From c9f2f394d46559f32369737f1a9f1921acfd93a6 Mon Sep 17 00:00:00 2001
From: Bart Feenstra <bart@mynameisbart.com>
Date: Tue, 5 May 2020 10:40:52 +0100
Subject: [PATCH 1/5] Generate resources based on template directories.

---
 betty/assets/templates/page/list-file.html.j2 |   7 -
 .../event/index.html.j2}                      |   5 +-
 .../resource-list/event/index.json.j2         |   0
 .../person/index.html.j2}                     |   3 +-
 .../resource-list/person/index.json.j2        |   0
 .../place/index.html.j2}                      |   3 +-
 .../resource-list/place/index.json.j2         |   0
 .../source/index.html.j2}                     |   3 +-
 .../resource-list/source/index.json.j2        |   0
 .../citation/index.html.j2}                   |   1 +
 .../templates/resource/citation/index.json.j2 |   1 +
 .../event/index.html.j2}                      |   1 +
 .../templates/resource/event/index.json.j2    |   1 +
 .../file/index.html.j2}                       |   1 +
 .../templates/resource/file/index.json.j2     |   1 +
 .../person/index.html.j2}                     |   1 +
 .../templates/resource/person/index.json.j2   |   1 +
 .../place/index.html.j2}                      |   1 +
 .../templates/resource/place/index.json.j2    |   1 +
 .../source/index.html.j2}                     |   1 +
 .../templates/resource/source/index.json.j2   |   1 +
 betty/fs.py                                   |  56 ++++---
 betty/generate.py                             | 146 +++++++-----------
 betty/jinja2.py                               |  24 +--
 betty/plugin/maps/__init__.py                 |   2 +-
 betty/plugin/nginx/__init__.py                |   2 +-
 betty/plugin/trees/__init__.py                |   2 +-
 betty/render.py                               |  16 +-
 betty/sass.py                                 |   6 +-
 betty/tests/test_fs.py                        |  31 +---
 30 files changed, 139 insertions(+), 179 deletions(-)
 delete mode 100644 betty/assets/templates/page/list-file.html.j2
 rename betty/assets/templates/{page/list-event.html.j2 => resource-list/event/index.html.j2} (53%)
 create mode 100644 betty/assets/templates/resource-list/event/index.json.j2
 rename betty/assets/templates/{page/list-person.html.j2 => resource-list/person/index.html.j2} (70%)
 create mode 100644 betty/assets/templates/resource-list/person/index.json.j2
 rename betty/assets/templates/{page/list-place.html.j2 => resource-list/place/index.html.j2} (71%)
 create mode 100644 betty/assets/templates/resource-list/place/index.json.j2
 rename betty/assets/templates/{page/list-source.html.j2 => resource-list/source/index.html.j2} (75%)
 create mode 100644 betty/assets/templates/resource-list/source/index.json.j2
 rename betty/assets/templates/{page/citation.html.j2 => resource/citation/index.html.j2} (96%)
 create mode 100644 betty/assets/templates/resource/citation/index.json.j2
 rename betty/assets/templates/{page/event.html.j2 => resource/event/index.html.j2} (98%)
 create mode 100644 betty/assets/templates/resource/event/index.json.j2
 rename betty/assets/templates/{page/file.html.j2 => resource/file/index.html.j2} (98%)
 create mode 100644 betty/assets/templates/resource/file/index.json.j2
 rename betty/assets/templates/{page/person.html.j2 => resource/person/index.html.j2} (99%)
 create mode 100644 betty/assets/templates/resource/person/index.json.j2
 rename betty/assets/templates/{page/place.html.j2 => resource/place/index.html.j2} (97%)
 create mode 100644 betty/assets/templates/resource/place/index.json.j2
 rename betty/assets/templates/{page/source.html.j2 => resource/source/index.html.j2} (97%)
 create mode 100644 betty/assets/templates/resource/source/index.json.j2

diff --git a/betty/assets/templates/page/list-file.html.j2 b/betty/assets/templates/page/list-file.html.j2
deleted file mode 100644
index 20afdf9c1..000000000
--- a/betty/assets/templates/page/list-file.html.j2
+++ /dev/null
@@ -1,7 +0,0 @@
-{% extends 'base.html.j2' %}
-{% set page_title = _('Media') %}
-{% block page_content %}
-    {% with files=entities %}
-        {% include 'list-file.html.j2' %}
-    {% endwith %}
-{% endblock %}
diff --git a/betty/assets/templates/page/list-event.html.j2 b/betty/assets/templates/resource-list/event/index.html.j2
similarity index 53%
rename from betty/assets/templates/page/list-event.html.j2
rename to betty/assets/templates/resource-list/event/index.html.j2
index d55a2c333..a3fbc06ed 100644
--- a/betty/assets/templates/page/list-event.html.j2
+++ b/betty/assets/templates/resource-list/event/index.html.j2
@@ -1,7 +1,6 @@
 {% extends 'base.html.j2' %}
+{% set events = file_resources %}
 {% set page_title = _('Events') %}
 {% block page_content %}
-    {% with events=entities %}
-        {% include 'list-event.html.j2' %}
-    {% endwith %}
+    {% include 'list-event.html.j2' %}
 {% endblock %}
diff --git a/betty/assets/templates/resource-list/event/index.json.j2 b/betty/assets/templates/resource-list/event/index.json.j2
new file mode 100644
index 000000000..e69de29bb
diff --git a/betty/assets/templates/page/list-person.html.j2 b/betty/assets/templates/resource-list/person/index.html.j2
similarity index 70%
rename from betty/assets/templates/page/list-person.html.j2
rename to betty/assets/templates/resource-list/person/index.html.j2
index 7f1226917..1fbc71393 100644
--- a/betty/assets/templates/page/list-person.html.j2
+++ b/betty/assets/templates/resource-list/person/index.html.j2
@@ -1,9 +1,10 @@
 {% extends 'base.html.j2' %}
+{% set people = file_resources %}
 {% set page_title = _('People') %}
 {% block page_content %}
     {% import 'macro/person.html.j2' as personMacros %}
     <ul class="entities">
-        {% for person in entities | rejectattr('private', 'eq', True) | rejectattr('name', 'none') | list | sort(attribute='name') %}
+        {% for person in people | rejectattr('private', 'eq', True) | rejectattr('name', 'none') | list | sort(attribute='name') %}
             <li class="{{ loop.cycle('odd', 'even') }}">
                 {{ personMacros.sortableLabel(person) }}
                 {% include 'meta/person.html.j2' %}
diff --git a/betty/assets/templates/resource-list/person/index.json.j2 b/betty/assets/templates/resource-list/person/index.json.j2
new file mode 100644
index 000000000..e69de29bb
diff --git a/betty/assets/templates/page/list-place.html.j2 b/betty/assets/templates/resource-list/place/index.html.j2
similarity index 71%
rename from betty/assets/templates/page/list-place.html.j2
rename to betty/assets/templates/resource-list/place/index.html.j2
index 30ddaef30..4f4ccb0cc 100644
--- a/betty/assets/templates/page/list-place.html.j2
+++ b/betty/assets/templates/resource-list/place/index.html.j2
@@ -1,7 +1,8 @@
 {% extends 'base.html.j2' %}
+{% set places = file_resources %}
 {% set page_title = _('Places') %}
 {% block page_content %}
-    {% with places=entities, canonical=True %}
+    {% with canonical=True %}
         {% include 'list-place.html.j2' %}
     {% endwith %}
 {% endblock %}
\ No newline at end of file
diff --git a/betty/assets/templates/resource-list/place/index.json.j2 b/betty/assets/templates/resource-list/place/index.json.j2
new file mode 100644
index 000000000..e69de29bb
diff --git a/betty/assets/templates/page/list-source.html.j2 b/betty/assets/templates/resource-list/source/index.html.j2
similarity index 75%
rename from betty/assets/templates/page/list-source.html.j2
rename to betty/assets/templates/resource-list/source/index.html.j2
index 99b58760e..d80d08ba9 100644
--- a/betty/assets/templates/page/list-source.html.j2
+++ b/betty/assets/templates/resource-list/source/index.html.j2
@@ -1,8 +1,9 @@
 {% extends 'base.html.j2' %}
+{% set sources = file_resources %}
 {% set page_title = _('Sources') %}
 {% block page_content %}
     <ul class="entities">
-        {% for source in entities | sort(attribute='name') %}
+        {% for source in sources | sort(attribute='name') %}
             <li class="{{ loop.cycle('odd', 'even') }}">
                 {% include 'label/source.html.j2' %}
             </li>
diff --git a/betty/assets/templates/resource-list/source/index.json.j2 b/betty/assets/templates/resource-list/source/index.json.j2
new file mode 100644
index 000000000..e69de29bb
diff --git a/betty/assets/templates/page/citation.html.j2 b/betty/assets/templates/resource/citation/index.html.j2
similarity index 96%
rename from betty/assets/templates/page/citation.html.j2
rename to betty/assets/templates/resource/citation/index.html.j2
index 1e338db46..a1c25366a 100644
--- a/betty/assets/templates/page/citation.html.j2
+++ b/betty/assets/templates/resource/citation/index.html.j2
@@ -1,4 +1,5 @@
 {% extends 'base.html.j2' %}
+{% set citation = file_resource %}
 {% set page_title = citation.location %}
 {% block page_content %}
     <div class="meta">
diff --git a/betty/assets/templates/resource/citation/index.json.j2 b/betty/assets/templates/resource/citation/index.json.j2
new file mode 100644
index 000000000..e518d5120
--- /dev/null
+++ b/betty/assets/templates/resource/citation/index.json.j2
@@ -0,0 +1 @@
+{{ file_resource | json }}
diff --git a/betty/assets/templates/page/event.html.j2 b/betty/assets/templates/resource/event/index.html.j2
similarity index 98%
rename from betty/assets/templates/page/event.html.j2
rename to betty/assets/templates/resource/event/index.html.j2
index c1838bdea..cf3964cb8 100644
--- a/betty/assets/templates/page/event.html.j2
+++ b/betty/assets/templates/resource/event/index.html.j2
@@ -1,4 +1,5 @@
 {% extends 'base.html.j2' %}
+{% set event = file_resource %}
 {% import 'macro/person.html.j2' as personMacros %}
 {% set page_title %}
     {% with embedded=True %}
diff --git a/betty/assets/templates/resource/event/index.json.j2 b/betty/assets/templates/resource/event/index.json.j2
new file mode 100644
index 000000000..e518d5120
--- /dev/null
+++ b/betty/assets/templates/resource/event/index.json.j2
@@ -0,0 +1 @@
+{{ file_resource | json }}
diff --git a/betty/assets/templates/page/file.html.j2 b/betty/assets/templates/resource/file/index.html.j2
similarity index 98%
rename from betty/assets/templates/page/file.html.j2
rename to betty/assets/templates/resource/file/index.html.j2
index 23a4ea008..24313e730 100644
--- a/betty/assets/templates/page/file.html.j2
+++ b/betty/assets/templates/resource/file/index.html.j2
@@ -1,4 +1,5 @@
 {% extends 'base.html.j2' %}
+{% set file = file_resource %}
 {% set page_title = file.description %}
 {% block page_content %}
     {% if file.media_type and file.media_type.startswith('image/') %}
diff --git a/betty/assets/templates/resource/file/index.json.j2 b/betty/assets/templates/resource/file/index.json.j2
new file mode 100644
index 000000000..e518d5120
--- /dev/null
+++ b/betty/assets/templates/resource/file/index.json.j2
@@ -0,0 +1 @@
+{{ file_resource | json }}
diff --git a/betty/assets/templates/page/person.html.j2 b/betty/assets/templates/resource/person/index.html.j2
similarity index 99%
rename from betty/assets/templates/page/person.html.j2
rename to betty/assets/templates/resource/person/index.html.j2
index c4d0fd70c..d1c5fb43f 100644
--- a/betty/assets/templates/page/person.html.j2
+++ b/betty/assets/templates/resource/person/index.html.j2
@@ -1,4 +1,5 @@
 {% extends 'base.html.j2' %}
+{% set person = file_resource %}
 {% import 'macro/person.html.j2' as personMacros %}
 {% set page_title %}
     {% with embedded=True %}
diff --git a/betty/assets/templates/resource/person/index.json.j2 b/betty/assets/templates/resource/person/index.json.j2
new file mode 100644
index 000000000..e518d5120
--- /dev/null
+++ b/betty/assets/templates/resource/person/index.json.j2
@@ -0,0 +1 @@
+{{ file_resource | json }}
diff --git a/betty/assets/templates/page/place.html.j2 b/betty/assets/templates/resource/place/index.html.j2
similarity index 97%
rename from betty/assets/templates/page/place.html.j2
rename to betty/assets/templates/resource/place/index.html.j2
index 845bebc71..1818ffaaa 100644
--- a/betty/assets/templates/page/place.html.j2
+++ b/betty/assets/templates/resource/place/index.html.j2
@@ -1,4 +1,5 @@
 {% extends 'base.html.j2' %}
+{% set place = file_resource %}
 {% set page_title = place.names | negotiate_localizeds %}
 {% block page_content %}
     {% include 'meta/place.html.j2' %}
diff --git a/betty/assets/templates/resource/place/index.json.j2 b/betty/assets/templates/resource/place/index.json.j2
new file mode 100644
index 000000000..e518d5120
--- /dev/null
+++ b/betty/assets/templates/resource/place/index.json.j2
@@ -0,0 +1 @@
+{{ file_resource | json }}
diff --git a/betty/assets/templates/page/source.html.j2 b/betty/assets/templates/resource/source/index.html.j2
similarity index 97%
rename from betty/assets/templates/page/source.html.j2
rename to betty/assets/templates/resource/source/index.html.j2
index c8ce44bf8..0e365baaf 100644
--- a/betty/assets/templates/page/source.html.j2
+++ b/betty/assets/templates/resource/source/index.html.j2
@@ -1,4 +1,5 @@
 {% extends 'base.html.j2' %}
+{% set source = file_resource %}
 {% set page_title = source.name %}
 {% block page_content %}
     {% include 'meta/source.html.j2' %}
diff --git a/betty/assets/templates/resource/source/index.json.j2 b/betty/assets/templates/resource/source/index.json.j2
new file mode 100644
index 000000000..e518d5120
--- /dev/null
+++ b/betty/assets/templates/resource/source/index.json.j2
@@ -0,0 +1 @@
+{{ file_resource | json }}
diff --git a/betty/fs.py b/betty/fs.py
index 5c7d5025c..26f113b41 100644
--- a/betty/fs.py
+++ b/betty/fs.py
@@ -4,9 +4,9 @@
 from collections import deque
 from contextlib import suppress
 from os import walk, path
-from os.path import join, dirname, exists, relpath, getmtime, basename
-from shutil import copy2
-from tempfile import mkdtemp
+from os.path import join, dirname, exists, relpath, getmtime
+from shutil import copy
+from tempfile import mkdtemp, TemporaryDirectory
 from typing import AsyncIterable
 
 
@@ -24,16 +24,29 @@ def hashfile(path: str) -> str:
     return hashlib.md5(':'.join([str(getmtime(path)), path]).encode('utf-8')).hexdigest()
 
 
-def is_hidden(path: str) -> bool:
-    if not path:
-        return False
-    name = basename(path)
-    while name:
-        name = basename(path)
-        if name.startswith('.'):
-            return True
-        path = dirname(path)
-    return False
+async def _copytree(source_path: str, destination_path: str):
+    async for file_source_path in iterfiles(source_path):
+        file_destination_path = join(destination_path, relpath(file_source_path, source_path))
+        if not exists(file_destination_path):
+            makedirs(dirname(file_destination_path))
+            copy(file_source_path, file_destination_path)
+
+
+class CopyTreeTo:
+    def __init__(self, file_system: 'FileSystem', source_path: str):
+        self._file_system = file_system
+        self._source_path = source_path
+
+    async def __aenter__(self):
+        self._intermediate_directory = TemporaryDirectory()
+        await self._file_system.copy_tree(self._source_path, self._intermediate_directory.name)
+        return self
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        self._intermediate_directory.cleanup()
+
+    async def copy_to(self, destination_path: str) -> None:
+        await _copytree(self._intermediate_directory.name, destination_path)
 
 
 class FileSystem:
@@ -51,24 +64,23 @@ async def open(self, *file_paths: str):
                     return open(join(fs_path, file_path))
         raise FileNotFoundError
 
-    async def copy2(self, source_path: str, destination_path: str) -> str:
+    async def copy(self, source_path: str, destination_path: str) -> str:
         for fs_path in self._paths:
             with suppress(FileNotFoundError):
-                return copy2(join(fs_path, source_path), destination_path)
+                return copy(join(fs_path, source_path), destination_path)
         tried_paths = [join(fs_path, source_path) for fs_path in self._paths]
         raise FileNotFoundError('Could not find any of %s.' %
                                 ', '.join(tried_paths))
 
-    async def copytree(self, source_path: str, destination_path: str) -> str:
+    async def copy_tree(self, source_path: str, destination_path: str) -> str:
+        makedirs(destination_path)
         for fs_path in self._paths:
-            async for file_source_path in iterfiles(join(fs_path, source_path)):
-                file_destination_path = join(destination_path, relpath(
-                    file_source_path, join(fs_path, source_path)))
-                if not exists(file_destination_path):
-                    makedirs(dirname(file_destination_path))
-                    copy2(file_source_path, file_destination_path)
+            await _copytree(join(fs_path, source_path), destination_path)
         return destination_path
 
+    def copy_tree_to(self, source_path: str) -> CopyTreeTo:
+        return CopyTreeTo(self, source_path)
+
 
 class DirectoryBackup:
     def __init__(self, root_path: str, backup_path: str):
diff --git a/betty/generate.py b/betty/generate.py
index ac3da0530..794599b30 100644
--- a/betty/generate.py
+++ b/betty/generate.py
@@ -1,64 +1,60 @@
 import logging
 import os
-from contextlib import suppress
 from json import dump
-from os import chmod
-from os.path import join
-from typing import Iterable, Any
+from os import chmod, path
+from typing import Iterable, Any, Union
 
-from jinja2 import Environment, TemplateNotFound
-
-from betty import jinja2
+from betty.ancestry import Resource, Identifiable
 from betty.event import Event
-from betty.fs import makedirs
-from betty.json import JSONEncoder
 from betty.openapi import build_specification
 from betty.site import Site
 
 
+IdentifiableResource = Union[Resource, Identifiable]
+
+
 class PostGenerateEvent(Event):
     pass  # pragma: no cover
 
 
 async def generate(site: Site) -> None:
     logger = logging.getLogger()
-    await site.assets.copytree(join('public', 'static'),
-                               site.configuration.www_directory_path)
+    await site.assets.copy_tree(path.join('public', 'static'),
+                                site.configuration.www_directory_path)
     await site.renderer.render_tree(site.configuration.www_directory_path)
     for locale, locale_configuration in site.configuration.locales.items():
         async with site.with_locale(locale) as site:
-            environment = jinja2.create_environment(site)
             if site.configuration.multilingual:
-                www_directory_path = join(
+                www_directory_path = path.join(
                     site.configuration.www_directory_path, locale_configuration.alias)
             else:
                 www_directory_path = site.configuration.www_directory_path
 
-            await site.assets.copytree(join('public', 'localized'), www_directory_path)
+            await site.assets.copy_tree(path.join('public', 'localized'), www_directory_path)
             await site.renderer.render_tree(www_directory_path)
 
-            await _generate_entity_type(www_directory_path, site.ancestry.files.values(
-            ), 'file', site, locale, environment)
+            await _generate_resource_type(www_directory_path, site.ancestry.files.values(
+            ), 'file', site)
             logger.info('Rendered %d files in %s.' %
                         (len(site.ancestry.files), locale))
-            await _generate_entity_type(www_directory_path, site.ancestry.people.values(
-            ), 'person', site, locale, environment)
+            await _generate_resource_type(www_directory_path, site.ancestry.people.values(
+            ), 'person', site)
             logger.info('Rendered %d people in %s.' %
                         (len(site.ancestry.people), locale))
-            await _generate_entity_type(www_directory_path, site.ancestry.places.values(
-            ), 'place', site, locale, environment)
+            await _generate_resource_type(www_directory_path, site.ancestry.places.values(
+            ), 'place', site)
             logger.info('Rendered %d places in %s.' %
                         (len(site.ancestry.places), locale))
-            await _generate_entity_type(www_directory_path, site.ancestry.events.values(
-            ), 'event', site, locale, environment)
+            await _generate_resource_type(www_directory_path, site.ancestry.events.values(
+            ), 'event', site)
             logger.info('Rendered %d events in %s.' %
                         (len(site.ancestry.events), locale))
-            await _generate_entity_type(www_directory_path, site.ancestry.citations.values(
-            ), 'citation', site, locale, environment)
+            await _generate_resource_type(www_directory_path, site.ancestry.citations.values(
+            ), 'citation', site)
             logger.info('Rendered %d citations in %s.' %
                         (len(site.ancestry.citations), locale))
-            await _generate_entity_type(www_directory_path, site.ancestry.sources.values(
-            ), 'source', site, locale, environment)
+            await _generate_resource_type(www_directory_path, site.ancestry.sources.values(
+            ), 'source', site)
             logger.info('Rendered %d sources in %s.' %
                         (len(site.ancestry.sources), locale))
             _generate_openapi(www_directory_path, site)
@@ -66,50 +62,43 @@ async def generate(site: Site) -> None:
     chmod(site.configuration.www_directory_path, 0o755)
     for directory_path, subdirectory_names, file_names in os.walk(site.configuration.www_directory_path):
         for subdirectory_name in subdirectory_names:
-            chmod(join(directory_path, subdirectory_name), 0o755)
+            chmod(path.join(directory_path, subdirectory_name), 0o755)
         for file_name in file_names:
-            chmod(join(directory_path, file_name), 0o644)
+            chmod(path.join(directory_path, file_name), 0o644)
     await site.event_dispatcher.dispatch(PostGenerateEvent())
 
 
-def _create_file(path: str) -> object:
-    makedirs(os.path.dirname(path))
-    return open(path, 'w')
-
-
-def _create_html_resource(path: str) -> object:
-    return _create_file(os.path.join(path, 'index.html'))
-
-
-def _create_json_resource(path: str) -> object:
-    return _create_file(os.path.join(path, 'index.json'))
-
-
-async def _generate_entity_type(www_directory_path: str, entities: Iterable[Any], entity_type_name: str, site: Site,
-                                locale: str, environment: Environment) -> None:
-    await _generate_entity_type_list_html(
-        www_directory_path, entities, entity_type_name, environment)
-    _generate_entity_type_list_json(
-        www_directory_path, entities, entity_type_name, site)
-    for entity in entities:
-        await _generate_entity(www_directory_path, entity,
-                               entity_type_name, site, locale, environment)
-
-
-async def _generate_entity_type_list_html(www_directory_path: str, entities: Iterable[Any], entity_type_name: str,
-                                          environment: Environment) -> None:
-    entity_type_path = os.path.join(www_directory_path, entity_type_name)
-    with suppress(TemplateNotFound):
-        template = environment.get_template(
-            'page/list-%s.html.j2' % entity_type_name)
-        with _create_html_resource(entity_type_path) as f:
-            f.write(await template.render_async({
-                'page_resource': '/%s/index.html' % entity_type_name,
-                'entity_type_name': entity_type_name,
-                'entities': entities,
-            }))
-
-
+async def _generate_resource_type(www_directory_path: str, resources: Iterable[IdentifiableResource], resource_type_name: str, site: Site) -> None:
+    await _generate_resource_list(site, www_directory_path, resources, resource_type_name)
+    # @todo We now generate each resource in isolation.
+    # @todo This means that for each resource, the FileSystem goes over each FS path to copy files.
+    # @todo For each resource, the same files are overridden, added, and, in the future, removed.
+    # @todo If we need to copy a tree to many destinations, we want to 'compile' the steps above.
+    # @todo 1) Either refactor FileSystem.copytree() to become a context manager: `with FileSystem.copytree(source_path) as copytree: copytree(desination_path)`
+    # @todo 2) Or refactor FileSystem.copytree() to take an Iterable[str] destination_path argument.
+    # @todo Internally, FileSystem.copytree() would first copy all files to a temporary directory, from which everything is then copied to all destination directories.
+    # @todo If the destination directory does not exist, the source directory
+    # @todo
+    resource_template_directory_path = path.join('templates', 'resource', resource_type_name)
+    async with site.assets.copy_tree_to(resource_template_directory_path) as copy_tree_to:
+        for resource in resources:
+            destination_path = path.join(www_directory_path, resource.resource_type_name, resource.id)
+            await copy_tree_to.copy_to(destination_path)
+            await site.renderer.render_tree(destination_path, {
+                'file_resource': resource,
+            })
+
+
+async def _generate_resource_list(site: Site, www_directory_path: str, resources: Iterable[IdentifiableResource], resource_type_name: str, ) -> None:
+    template_directory_path = path.join('templates', 'resource-list', resource_type_name)
+    destination_path = path.join(www_directory_path, resource_type_name)
+    await site.assets.copy_tree(template_directory_path, destination_path)
+    await site.renderer.render_tree(destination_path, {
+        'file_resources': resources,
+    })
+
+
+# @todo Move this to the list *.json.j2 files.
 def _generate_entity_type_list_json(www_directory_path: str, entities: Iterable[Any], entity_type_name: str, site: Site) -> None:
     entity_type_path = os.path.join(www_directory_path, entity_type_name)
     with _create_json_resource(entity_type_path) as f:
@@ -123,29 +112,6 @@ def _generate_entity_type_list_json(www_directory_path: str, entities: Iterable[
         dump(data, f)
 
 
-async def _generate_entity(www_directory_path: str, entity: Any, entity_type_name: str, site: Site, locale: str, environment: Environment) -> None:
-    await _generate_entity_html(www_directory_path, entity,
-                                entity_type_name, environment)
-    _generate_entity_json(www_directory_path, entity,
-                          entity_type_name, site, locale)
-
-
-async def _generate_entity_html(www_directory_path: str, entity: Any, entity_type_name: str, environment: Environment) -> None:
-    entity_path = os.path.join(www_directory_path, entity_type_name, entity.id)
-    with _create_html_resource(entity_path) as f:
-        f.write(await environment.get_template('page/%s.html.j2' % entity_type_name).render_async({
-            'page_resource': entity,
-            'entity_type_name': entity_type_name,
-            entity_type_name: entity,
-        }))
-
-
-def _generate_entity_json(www_directory_path: str, entity: Any, entity_type_name: str, site: Site, locale: str) -> None:
-    entity_path = os.path.join(www_directory_path, entity_type_name, entity.id)
-    with _create_json_resource(entity_path) as f:
-        dump(entity, f, cls=JSONEncoder.get_factory(site, locale))
-
-
 def _generate_openapi(www_directory_path: str, site: Site) -> None:
-    with open(join(www_directory_path, 'api', 'index.json'), 'w') as f:
+    with open(path.join(www_directory_path, 'api', 'index.json'), 'w') as f:
         dump(build_specification(site), f)
diff --git a/betty/jinja2.py b/betty/jinja2.py
index 487476de3..b953c5abb 100644
--- a/betty/jinja2.py
+++ b/betty/jinja2.py
@@ -21,13 +21,13 @@
 
 from betty.ancestry import File, Citation, Identifiable, Resource, HasLinks, Subject, Witness
 from betty.config import Configuration
-from betty.fs import makedirs, hashfile, is_hidden, iterfiles
+from betty.fs import makedirs, hashfile, iterfiles
 from betty.functools import walk, asynciter
 from betty.importlib import import_any
 from betty.json import JSONEncoder
 from betty.locale import negotiate_localizeds, Localized, format_datey, Datey, negotiate_locale
 from betty.plugin import Plugin
-from betty.render import Renderer
+from betty.render import Renderer, FileArguments
 from betty.search import Index
 from betty.site import Site
 
@@ -195,28 +195,20 @@ def __init__(self, environment: Environment, configuration: Configuration):
         self._environment = environment
         self._configuration = configuration
 
-    async def render_file(self, file_path: str) -> None:
+    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
         if not file_path.endswith('.j2'):
             return
         file_destination_path = file_path[:-3]
-        data = {}
-        if file_destination_path.startswith(self._configuration.www_directory_path) and not is_hidden(file_destination_path):
-            # Unix-style paths use forward slashes, so they are valid URL paths.
-            resource = file_destination_path[len(
-                self._configuration.www_directory_path):]
-            if self._configuration.multilingual:
-                resource_parts = resource.lstrip('/').split('/')
-                if resource_parts[0] in map(lambda x: x.alias, self._configuration.locales.values()):
-                    resource = '/'.join(resource_parts[1:])
-            data['page_resource'] = resource
         template = _root_loader.load(self._environment, file_path, self._environment.globals)
+        if file_arguments is None:
+            file_arguments = {}
         with open(file_destination_path, 'w') as f:
-            f.write(await template.render_async(data))
+            f.write(await template.render_async(**file_arguments))
         os.remove(file_path)
 
-    async def render_tree(self, tree_path: str) -> None:
+    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
         await asyncio.gather(
-            *[self.render_file(file_path) async for file_path in iterfiles(tree_path) if file_path.endswith('.j2')],
+            *[self.render_file(file_path, file_arguments) async for file_path in iterfiles(tree_path) if file_path.endswith('.j2')],
         )
 
 
diff --git a/betty/plugin/maps/__init__.py b/betty/plugin/maps/__init__.py
index a8ebd3029..fe5b96ea7 100644
--- a/betty/plugin/maps/__init__.py
+++ b/betty/plugin/maps/__init__.py
@@ -51,7 +51,7 @@ async def _render(self, event: PostGenerateEvent) -> None:
                    cwd=js_plugin_build_directory_path)
 
         # Run Webpack.
-        await self._site.assets.copy2(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
+        await self._site.assets.copy(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
             js_plugin_build_directory_path, 'betty.css'))
         check_call(['npm', 'run', 'webpack'],
                    cwd=js_plugin_build_directory_path)
diff --git a/betty/plugin/nginx/__init__.py b/betty/plugin/nginx/__init__.py
index b4a427419..8ae3ca833 100644
--- a/betty/plugin/nginx/__init__.py
+++ b/betty/plugin/nginx/__init__.py
@@ -56,7 +56,7 @@ async def _generate_config(self, event: PostGenerateEvent) -> None:
         # Render the ngnix configuration.
         file_name = 'nginx.conf.j2'
         destination_file_path = os.path.join(output_directory_path, file_name)
-        await self._site.assets.copy2(file_name, destination_file_path)
+        await self._site.assets.copy(file_name, destination_file_path)
         await self._site.renderer.render_file(destination_file_path)
 
         # Render the Dockerfile.
diff --git a/betty/plugin/trees/__init__.py b/betty/plugin/trees/__init__.py
index daf02e840..aeed2d368 100644
--- a/betty/plugin/trees/__init__.py
+++ b/betty/plugin/trees/__init__.py
@@ -51,7 +51,7 @@ async def _render(self, event: PostGenerateEvent) -> None:
                    cwd=js_plugin_build_directory_path)
 
         # Run Webpack.
-        await self._site.assets.copy2(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
+        await self._site.assets.copy(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
             js_plugin_build_directory_path, 'betty.css'))
         check_call(['npm', 'run', 'webpack'],
                    cwd=js_plugin_build_directory_path)
diff --git a/betty/render.py b/betty/render.py
index ed400133e..1a4b9a161 100644
--- a/betty/render.py
+++ b/betty/render.py
@@ -1,11 +1,13 @@
-from typing import List
+from typing import List, Optional, Dict, Any
+
+FileArguments = Optional[Dict[str, Any]]
 
 
 class Renderer:
-    async def render_file(self, file_path: str) -> None:
+    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
         raise NotImplementedError
 
-    async def render_tree(self, tree_path: str) -> None:
+    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
         raise NotImplementedError
 
 
@@ -13,10 +15,10 @@ class SequentialRenderer(Renderer):
     def __init__(self, renderers: List[Renderer]):
         self._renderers = renderers
 
-    async def render_file(self, file_path: str) -> None:
+    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
         for renderer in self._renderers:
-            await renderer.render_file(file_path)
+            await renderer.render_file(file_path, file_arguments)
 
-    async def render_tree(self, tree_path: str) -> None:
+    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
         for renderer in self._renderers:
-            await renderer.render_tree(tree_path)
+            await renderer.render_tree(tree_path, file_arguments)
diff --git a/betty/sass.py b/betty/sass.py
index 768387856..e99ba6f50 100644
--- a/betty/sass.py
+++ b/betty/sass.py
@@ -3,19 +3,19 @@
 
 import sass
 
-from betty.render import Renderer
+from betty.render import Renderer, FileArguments
 
 
 class SassRenderer(Renderer):
     _EXTENSIONS = ('sass', 'scss')
 
-    async def render_file(self, file_path: str) -> None:
+    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
         if not file_path.endswith(self._EXTENSIONS):
             return
         self._compile(filename=file_path)
         os.remove(file_path)
 
-    async def render_tree(self, tree_path: str) -> None:
+    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
         self._compile(dirname=(tree_path, tree_path))
         for extension in self._EXTENSIONS:
             patterns = [
diff --git a/betty/tests/test_fs.py b/betty/tests/test_fs.py
index 05f402567..d3b6b45b3 100644
--- a/betty/tests/test_fs.py
+++ b/betty/tests/test_fs.py
@@ -4,9 +4,7 @@
 from tempfile import TemporaryDirectory
 from unittest import TestCase
 
-from parameterized import parameterized
-
-from betty.fs import iterfiles, FileSystem, hashfile, is_hidden
+from betty.fs import iterfiles, FileSystem, hashfile
 from betty.functools import sync
 
 
@@ -43,23 +41,6 @@ def test_hashfile_with_different_files(self):
         self.assertNotEquals(hashfile(file_path_1), hashfile(file_path_2))
 
 
-class IsHiddenTest(TestCase):
-    @parameterized.expand([
-        (True, '.betty'),
-        (True, '.betty.log'),
-        (True, '/etc/.betty/betty'),
-        (True, '/etc/.betty/betty.log'),
-        (False, ''),
-        (False, '/'),
-        (False, 'betty'),
-        (False, 'betty.log'),
-        (False, 'betty/betty.log'),
-        (False, '/etc/betty.log'),
-    ])
-    def test(self, expected, path):
-        self.assertEquals(expected, is_hidden(path))
-
-
 class FileSystemTest(TestCase):
     @sync
     async def test_open(self):
@@ -151,9 +132,9 @@ async def test_copy2(self):
                 with TemporaryDirectory() as destination_path:
                     sut = FileSystem(source_path_1, source_path_2)
 
-                    await sut.copy2('apples', destination_path)
-                    await sut.copy2('oranges', destination_path)
-                    await sut.copy2('bananas', destination_path)
+                    await sut.copy('apples', destination_path)
+                    await sut.copy('oranges', destination_path)
+                    await sut.copy('bananas', destination_path)
 
                     with await sut.open(join(destination_path, 'apples')) as f:
                         self.assertEquals('apples', f.read())
@@ -163,7 +144,7 @@ async def test_copy2(self):
                         self.assertEquals('bananas', f.read())
 
                     with self.assertRaises(FileNotFoundError):
-                        await sut.copy2('mangos', destination_path)
+                        await sut.copy('mangos', destination_path)
 
     @sync
     async def test_copytree(self):
@@ -183,7 +164,7 @@ async def test_copytree(self):
                 with TemporaryDirectory() as destination_path:
                     sut = FileSystem(source_path_1, source_path_2)
 
-                    await sut.copytree('', destination_path)
+                    await sut.copy_tree('', destination_path)
 
                     with await sut.open(join(destination_path, 'basket', 'apples')) as f:
                         self.assertEquals('apples', f.read())

From d68d95b0542abb78df6f521d19927efe38f808eb Mon Sep 17 00:00:00 2001
From: Bart Feenstra <bart@mynameisbart.com>
Date: Thu, 7 May 2020 20:55:50 +0100
Subject: [PATCH 2/5] More work.

---
 betty/cli.py                   |  8 +++--
 betty/fs.py                    | 66 +++++++++++++++-------------------
 betty/generate.py              | 38 +++++++-------------
 betty/jinja2.py                | 11 +++---
 betty/plugin/maps/__init__.py  |  2 +-
 betty/plugin/nginx/__init__.py |  4 +--
 betty/plugin/trees/__init__.py |  2 +-
 betty/render.py                | 19 ++++------
 betty/sass.py                  | 33 ++++++-----------
 betty/tests/test_jinja2.py     | 28 +++++++--------
 setup.py                       |  1 +
 11 files changed, 89 insertions(+), 123 deletions(-)

diff --git a/betty/cli.py b/betty/cli.py
index 331449360..fb7d6b37a 100644
--- a/betty/cli.py
+++ b/betty/cli.py
@@ -1,4 +1,6 @@
+import cProfile
 import logging
+import pstats
 import shutil
 from contextlib import suppress
 from functools import wraps
@@ -118,5 +120,7 @@ async def _clear_caches():
 @click.command(help='Generate a static site.')
 @site_command
 async def _generate(site: Site):
-    await parse.parse(site)
-    await generate.generate(site)
+    with cProfile.Profile() as pr:
+        await parse.parse(site)
+        await generate.generate(site)
+    pstats.Stats(pr).strip_dirs().sort_stats(pstats.SortKey.CUMULATIVE).print_stats()
diff --git a/betty/fs.py b/betty/fs.py
index 26f113b41..95ab908b8 100644
--- a/betty/fs.py
+++ b/betty/fs.py
@@ -4,32 +4,33 @@
 from collections import deque
 from contextlib import suppress
 from os import walk, path
-from os.path import join, dirname, exists, relpath, getmtime
-from shutil import copy
 from tempfile import mkdtemp, TemporaryDirectory
-from typing import AsyncIterable
+from typing import Iterable
 
 
-async def iterfiles(path: str) -> AsyncIterable[str]:
-    for dir_path, _, filenames in walk(path):
+def iterfiles(file_path: str) -> Iterable[str]:
+    for dir_path, _, filenames in walk(file_path):
         for filename in filenames:
-            yield join(dir_path, filename)
+            yield path.join(dir_path, filename)
 
 
-def makedirs(path: str) -> None:
-    os.makedirs(path, 0o755, True)
+def makedirs(file_path: str) -> None:
+    os.makedirs(file_path, 0o755, True)
 
 
-def hashfile(path: str) -> str:
-    return hashlib.md5(':'.join([str(getmtime(path)), path]).encode('utf-8')).hexdigest()
+def hashfile(file_path: str) -> str:
+    return hashlib.md5(':'.join([str(path.getmtime(file_path)), file_path]).encode('utf-8')).hexdigest()
 
 
-async def _copytree(source_path: str, destination_path: str):
-    async for file_source_path in iterfiles(source_path):
-        file_destination_path = join(destination_path, relpath(file_source_path, source_path))
-        if not exists(file_destination_path):
-            makedirs(dirname(file_destination_path))
-            copy(file_source_path, file_destination_path)
+def copy_tree(source_path: str, destination_path: str):
+    makedirs(destination_path)
+    for file_source_path in iterfiles(source_path):
+        file_destination_path = path.join(destination_path, path.relpath(file_source_path, source_path))
+        try:
+            shutil.copy(file_source_path, file_destination_path)
+        except FileNotFoundError:
+            makedirs(path.dirname(file_destination_path))
+            shutil.copy(file_source_path, file_destination_path)
 
 
 class CopyTreeTo:
@@ -37,16 +38,16 @@ def __init__(self, file_system: 'FileSystem', source_path: str):
         self._file_system = file_system
         self._source_path = source_path
 
-    async def __aenter__(self):
+    def __enter__(self) -> 'CopyTreeTo':
         self._intermediate_directory = TemporaryDirectory()
-        await self._file_system.copy_tree(self._source_path, self._intermediate_directory.name)
+        self._file_system.copy_tree(self._source_path, self._intermediate_directory.name)
         return self
 
-    async def __aexit__(self, exc_type, exc_val, exc_tb):
-        self._intermediate_directory.cleanup()
+    def __call__(self, destination_path: str) -> None:
+        copy_tree(self._intermediate_directory.name, destination_path)
 
-    async def copy_to(self, destination_path: str) -> None:
-        await _copytree(self._intermediate_directory.name, destination_path)
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._intermediate_directory.cleanup()
 
 
 class FileSystem:
@@ -57,26 +58,15 @@ def __init__(self, *paths):
     def paths(self) -> deque:
         return self._paths
 
-    async def open(self, *file_paths: str):
-        for file_path in file_paths:
-            for fs_path in self._paths:
-                with suppress(FileNotFoundError):
-                    return open(join(fs_path, file_path))
-        raise FileNotFoundError
-
-    async def copy(self, source_path: str, destination_path: str) -> str:
+    def copy(self, source_path: str, destination_path: str) -> None:
         for fs_path in self._paths:
             with suppress(FileNotFoundError):
-                return copy(join(fs_path, source_path), destination_path)
-        tried_paths = [join(fs_path, source_path) for fs_path in self._paths]
-        raise FileNotFoundError('Could not find any of %s.' %
-                                ', '.join(tried_paths))
+                shutil.copyfile(path.join(fs_path, source_path), destination_path)
 
-    async def copy_tree(self, source_path: str, destination_path: str) -> str:
-        makedirs(destination_path)
+    def copy_tree(self, source_path: str, destination_path: str) -> None:
         for fs_path in self._paths:
-            await _copytree(join(fs_path, source_path), destination_path)
-        return destination_path
+            with suppress(FileNotFoundError):
+                copy_tree(path.join(fs_path, source_path), destination_path)
 
     def copy_tree_to(self, source_path: str) -> CopyTreeTo:
         return CopyTreeTo(self, source_path)
diff --git a/betty/generate.py b/betty/generate.py
index 794599b30..0d3a0b03e 100644
--- a/betty/generate.py
+++ b/betty/generate.py
@@ -6,6 +6,7 @@
 
 from betty.ancestry import Resource, Identifiable
 from betty.event import Event
+from betty.fs import iterfiles
 from betty.openapi import build_specification
 from betty.site import Site
 
@@ -19,7 +20,7 @@ class PostGenerateEvent(Event):
 
 async def generate(site: Site) -> None:
     logger = logging.getLogger()
-    await site.assets.copy_tree(path.join('public', 'static'),
+    site.assets.copy_tree(path.join('public', 'static'),
                                 site.configuration.www_directory_path)
     await site.renderer.render_tree(site.configuration.www_directory_path)
     for locale, locale_configuration in site.configuration.locales.items():
@@ -30,7 +31,7 @@ async def generate(site: Site) -> None:
             else:
                 www_directory_path = site.configuration.www_directory_path
 
-            await site.assets.copy_tree(path.join('public', 'localized'), www_directory_path)
+            site.assets.copy_tree(path.join('public', 'localized'), www_directory_path)
             await site.renderer.render_tree(www_directory_path)
 
             await _generate_resource_type(www_directory_path, site.ancestry.files.values(
@@ -69,35 +70,22 @@ async def generate(site: Site) -> None:
 
 
 async def _generate_resource_type(www_directory_path: str, resources: Iterable[IdentifiableResource], resource_type_name: str, site: Site) -> None:
-    await _generate_resource_list(site, www_directory_path, resources, resource_type_name)
-    # @todo We now generate each resource in isolation.
-    # @todo This means that for each resource, the FileSystem goes over each FS path to copy files.
-    # @todo For each resource, the same files are overridden, added, and, in the future, removed.
-    # @todo If we need to copy a tree to many destinations, we want to 'compile' the steps above.
-    # @todo 1) Either refactor FileSystem.copytree() to become a context manager: `with FileSystem.copytree(source_path) as copytree: copytree(desination_path)`
-    # @todo 2) Or refactor FileSystem.copytree() to take an Iterable[str] destination_path argument.
-    # @todo Internally, FileSystem.copytree() would first copy all files to a temporary directory, from which everything is then copied to all destination directories.
-    # @todo If the destination directory does not exist, the source directory
-    # @todo
+    resources_template_directory_path = path.join('templates', 'resource-list', resource_type_name)
+    resources_destination_path = path.join(www_directory_path, resource_type_name)
+    site.assets.copy_tree(resources_template_directory_path, resources_destination_path)
+    await site.renderer.render_tree(resources_destination_path, {
+        'file_resources': resources,
+    })
     resource_template_directory_path = path.join('templates', 'resource', resource_type_name)
-    async with site.assets.copy_tree_to(resource_template_directory_path) as copy_tree_to:
+    with site.assets.copy_tree_to(resource_template_directory_path) as copy_tree_to:
         for resource in resources:
-            destination_path = path.join(www_directory_path, resource.resource_type_name, resource.id)
-            await copy_tree_to.copy_to(destination_path)
-            await site.renderer.render_tree(destination_path, {
+            resource_destination_path = path.join(www_directory_path, resource.resource_type_name, resource.id)
+            copy_tree_to(resource_destination_path)
+            await site.renderer.render_tree(resource_destination_path, {
                 'file_resource': resource,
             })
 
 
-async def _generate_resource_list(site: Site, www_directory_path: str, resources: Iterable[IdentifiableResource], resource_type_name: str, ) -> None:
-    template_directory_path = path.join('templates', 'resource-list', resource_type_name)
-    destination_path = path.join(www_directory_path, resource_type_name)
-    await site.assets.copy_tree(template_directory_path, destination_path)
-    await site.renderer.render_tree(destination_path, {
-        'file_resources': resources,
-    })
-
-
 # @todo Move this to the list *.json.j2 files.
 def _generate_entity_type_list_json(www_directory_path: str, entities: Iterable[Any], entity_type_name: str, site: Site) -> None:
     entity_type_path = os.path.join(www_directory_path, entity_type_name)
diff --git a/betty/jinja2.py b/betty/jinja2.py
index b953c5abb..47dfc2588 100644
--- a/betty/jinja2.py
+++ b/betty/jinja2.py
@@ -7,6 +7,7 @@
 from typing import Union, Dict, Type, Optional, Callable, Iterable
 from urllib.parse import urlparse
 
+from aiofiles import os as aioos
 from PIL import Image
 from babel import Locale
 from geopy import units
@@ -27,7 +28,7 @@
 from betty.json import JSONEncoder
 from betty.locale import negotiate_localizeds, Localized, format_datey, Datey, negotiate_locale
 from betty.plugin import Plugin
-from betty.render import Renderer, FileArguments
+from betty.render import Renderer, RenderArguments
 from betty.search import Index
 from betty.site import Site
 
@@ -195,7 +196,7 @@ def __init__(self, environment: Environment, configuration: Configuration):
         self._environment = environment
         self._configuration = configuration
 
-    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
+    async def _render_file(self, file_path: str, file_arguments: RenderArguments = None) -> None:
         if not file_path.endswith('.j2'):
             return
         file_destination_path = file_path[:-3]
@@ -204,11 +205,11 @@ async def render_file(self, file_path: str, file_arguments: FileArguments = None
             file_arguments = {}
         with open(file_destination_path, 'w') as f:
             f.write(await template.render_async(**file_arguments))
-        os.remove(file_path)
+        await aioos.remove(file_path)
 
-    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
+    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
         await asyncio.gather(
-            *[self.render_file(file_path, file_arguments) async for file_path in iterfiles(tree_path) if file_path.endswith('.j2')],
+            *[self._render_file(file_path, file_arguments) for file_path in iterfiles(render_path)],
         )
 
 
diff --git a/betty/plugin/maps/__init__.py b/betty/plugin/maps/__init__.py
index fe5b96ea7..99efcb9ef 100644
--- a/betty/plugin/maps/__init__.py
+++ b/betty/plugin/maps/__init__.py
@@ -51,7 +51,7 @@ async def _render(self, event: PostGenerateEvent) -> None:
                    cwd=js_plugin_build_directory_path)
 
         # Run Webpack.
-        await self._site.assets.copy(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
+        self._site.assets.copy(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
             js_plugin_build_directory_path, 'betty.css'))
         check_call(['npm', 'run', 'webpack'],
                    cwd=js_plugin_build_directory_path)
diff --git a/betty/plugin/nginx/__init__.py b/betty/plugin/nginx/__init__.py
index 8ae3ca833..bdc795a1a 100644
--- a/betty/plugin/nginx/__init__.py
+++ b/betty/plugin/nginx/__init__.py
@@ -56,8 +56,8 @@ async def _generate_config(self, event: PostGenerateEvent) -> None:
         # Render the ngnix configuration.
         file_name = 'nginx.conf.j2'
         destination_file_path = os.path.join(output_directory_path, file_name)
-        await self._site.assets.copy(file_name, destination_file_path)
-        await self._site.renderer.render_file(destination_file_path)
+        self._site.assets.copy(file_name, destination_file_path)
+        await self._site.renderer.render_tree(output_directory_path)
 
         # Render the Dockerfile.
         copyfile(os.path.join(DOCKER_PATH, 'Dockerfile'), os.path.join(output_directory_path, 'Dockerfile'))
diff --git a/betty/plugin/trees/__init__.py b/betty/plugin/trees/__init__.py
index aeed2d368..4d7ff55d6 100644
--- a/betty/plugin/trees/__init__.py
+++ b/betty/plugin/trees/__init__.py
@@ -51,7 +51,7 @@ async def _render(self, event: PostGenerateEvent) -> None:
                    cwd=js_plugin_build_directory_path)
 
         # Run Webpack.
-        await self._site.assets.copy(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
+        self._site.assets.copy(path.join(self._site.configuration.www_directory_path, 'betty.css'), path.join(
             js_plugin_build_directory_path, 'betty.css'))
         check_call(['npm', 'run', 'webpack'],
                    cwd=js_plugin_build_directory_path)
diff --git a/betty/render.py b/betty/render.py
index 1a4b9a161..46ffd0e73 100644
--- a/betty/render.py
+++ b/betty/render.py
@@ -1,24 +1,17 @@
-from typing import List, Optional, Dict, Any
+from typing import Optional, Dict, Any, Sequence
 
-FileArguments = Optional[Dict[str, Any]]
+RenderArguments = Optional[Dict[str, Any]]
 
 
 class Renderer:
-    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
-        raise NotImplementedError
-
-    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
+    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
         raise NotImplementedError
 
 
 class SequentialRenderer(Renderer):
-    def __init__(self, renderers: List[Renderer]):
+    def __init__(self, renderers: Sequence[Renderer]):
         self._renderers = renderers
 
-    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
-        for renderer in self._renderers:
-            await renderer.render_file(file_path, file_arguments)
-
-    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
+    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
         for renderer in self._renderers:
-            await renderer.render_tree(tree_path, file_arguments)
+            await renderer.render_tree(render_path, file_arguments)
diff --git a/betty/sass.py b/betty/sass.py
index e99ba6f50..2b9aa0bc1 100644
--- a/betty/sass.py
+++ b/betty/sass.py
@@ -1,32 +1,21 @@
+import asyncio
 import os
 from glob import glob
 
+from aiofiles import os as aioos
 import sass
 
-from betty.render import Renderer, FileArguments
+from betty.render import Renderer, RenderArguments
 
 
 class SassRenderer(Renderer):
     _EXTENSIONS = ('sass', 'scss')
 
-    async def render_file(self, file_path: str, file_arguments: FileArguments = None) -> None:
-        if not file_path.endswith(self._EXTENSIONS):
-            return
-        self._compile(filename=file_path)
-        os.remove(file_path)
-
-    async def render_tree(self, tree_path: str, file_arguments: FileArguments = None) -> None:
-        self._compile(dirname=(tree_path, tree_path))
-        for extension in self._EXTENSIONS:
-            patterns = [
-                # Files in the path.
-                os.path.join(tree_path, '*.' + extension),
-                # Files in the path's subdirectories.
-                os.path.join(tree_path, '**', '*.' + extension),
-            ]
-            for pattern in patterns:
-                for file_path in glob(pattern):
-                    os.remove(file_path)
-
-    def _compile(self, **kwargs) -> None:
-        sass.compile(output_style='compressed', **kwargs)
+    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
+        sass.compile(dirname=(render_path, render_path))
+        await asyncio.gather(*[aioos.remove(file_path) for extension in self._EXTENSIONS for pattern in [
+            # Files in the path.
+            os.path.join(render_path, '*.' + extension),
+            # Files in the path's subdirectories.
+            os.path.join(render_path, '**', '*.' + extension),
+        ] for file_path in glob(pattern)])
diff --git a/betty/tests/test_jinja2.py b/betty/tests/test_jinja2.py
index 4748be64a..2c714d5cb 100644
--- a/betty/tests/test_jinja2.py
+++ b/betty/tests/test_jinja2.py
@@ -26,7 +26,7 @@ def test(self, expected, template):
             environment = create_environment(
                 Site(Configuration(www_directory_path, 'https://example.com')))
             self.assertEquals(
-                expected, environment.from_string(template).render())
+                expected, environment.from_string(template).render_tree())
 
 
 class WalkData:
@@ -49,7 +49,7 @@ def test(self, expected, template, data):
             environment = create_environment(
                 Site(Configuration(www_directory_path, 'https://example.com')))
             self.assertEquals(expected, environment.from_string(
-                template).render(data=data))
+                template).render_tree(data=data))
 
 
 class ParagraphsTest(TestCase):
@@ -63,7 +63,7 @@ def test(self, expected, template):
             environment = create_environment(
                 Site(Configuration(www_directory_path, 'https://example.com')))
             self.assertEquals(
-                expected, environment.from_string(template).render())
+                expected, environment.from_string(template).render_tree())
 
 
 class FormatDegreesTest(TestCase):
@@ -76,7 +76,7 @@ def test(self, expected, template):
             environment = create_environment(
                 Site(Configuration(www_directory_path, 'https://example.com')))
             self.assertEquals(
-                expected, environment.from_string(template).render())
+                expected, environment.from_string(template).render_tree())
 
 
 class MapData:
@@ -97,7 +97,7 @@ def test(self, expected, template, data):
             environment = create_environment(
                 Site(Configuration(www_directory_path, 'https://example.com')))
             self.assertEquals(expected, environment.from_string(
-                template).render(data=data))
+                template).render_tree(data=data))
 
 
 class TakewhileTest(TestCase):
@@ -113,7 +113,7 @@ def test(self, expected, template):
             environment = create_environment(
                 Site(Configuration(www_directory_path, 'https://example.com')))
             self.assertEquals(
-                expected, environment.from_string(template).render())
+                expected, environment.from_string(template).render_tree())
 
 
 class FileTest(TestCase):
@@ -127,7 +127,7 @@ def test(self, expected, template, file):
             configuration = Configuration(
                 output_directory_path, 'https://example.com')
             environment = create_environment(Site(configuration))
-            actual = environment.from_string(template).render(file=file)
+            actual = environment.from_string(template).render_tree(file=file)
             self.assertEquals(expected, actual)
             for file_path in actual.split(':'):
                 self.assertTrue(
@@ -154,7 +154,7 @@ def test(self, expected, template, file):
             configuration = Configuration(
                 output_directory_path, 'https://example.com')
             environment = create_environment(Site(configuration))
-            actual = environment.from_string(template).render(file=file)
+            actual = environment.from_string(template).render_tree(file=file)
             self.assertEquals(expected, actual)
             for file_path in actual.split(':'):
                 self.assertTrue(
@@ -172,7 +172,7 @@ def test_with_unknown_plugin_module(self):
                 Site(Configuration(www_directory_path, 'https://example.com')))
             template = '{% if "betty.UnknownModule.Plugin" in plugins %}true{% else %}false{% endif %}'
             self.assertEquals(
-                'false', environment.from_string(template).render())
+                'false', environment.from_string(template).render_tree())
 
     def test_with_unknown_plugin_class(self):
         with TemporaryDirectory() as www_directory_path:
@@ -180,7 +180,7 @@ def test_with_unknown_plugin_class(self):
                 Site(Configuration(www_directory_path, 'https://example.com')))
             template = '{% if "betty.UnknownPlugin" in plugins %}true{% else %}false{% endif %}'
             self.assertEquals(
-                'false', environment.from_string(template).render())
+                'false', environment.from_string(template).render_tree())
 
     def test_with_disabled_plugin(self):
         with TemporaryDirectory() as www_directory_path:
@@ -189,7 +189,7 @@ def test_with_disabled_plugin(self):
             template = '{% if "' + TestPlugin.__module__ + \
                 '.TestPlugin" in plugins %}true{% else %}false{% endif %}'
             self.assertEquals(
-                'false', environment.from_string(template).render())
+                'false', environment.from_string(template).render_tree())
 
     def test_with_enabled_plugin(self):
         with TemporaryDirectory() as www_directory_path:
@@ -200,7 +200,7 @@ def test_with_enabled_plugin(self):
             template = '{% if "' + TestPlugin.__module__ + \
                 '.TestPlugin" in plugins %}true{% else %}false{% endif %}'
             self.assertEquals(
-                'true', environment.from_string(template).render())
+                'true', environment.from_string(template).render_tree())
 
 
 class FormatDateTest(TestCase):
@@ -244,7 +244,7 @@ def test(self):
                     LocalizedName('1', 'en-US'),
                 ]),
             ]
-            self.assertEquals('[first, second, third]', environment.from_string(template).render(data=data))
+            self.assertEquals('[first, second, third]', environment.from_string(template).render_tree(data=data))
 
     def test_with_empty_iterable(self):
         with TemporaryDirectory() as www_directory_path:
@@ -253,7 +253,7 @@ def test_with_empty_iterable(self):
             environment = create_environment(Site(configuration))
             template = '{{ data | sort_localizeds(localized_attribute="names", sort_attribute="name") }}'
             data = []
-            self.assertEquals('[]', environment.from_string(template).render(data=data))
+            self.assertEquals('[]', environment.from_string(template).render_tree(data=data))
 
 
 class SelectLocalizedsTest(TestCase):
diff --git a/setup.py b/setup.py
index 443c18a2c..dcd7e835e 100644
--- a/setup.py
+++ b/setup.py
@@ -36,6 +36,7 @@
     ],
     'python_requires': '~= 3.6',
     'install_requires': [
+        'aiofiles ~= 0.5.0',
         'aiohttp ~= 3.6.2',
         'async-exit-stack ~= 1.0.0; python_version <= "3.6"',
         'babel ~= 2.7.0',

From 840342000fe717a988f7f6800a4f625c5eb2bd9d Mon Sep 17 00:00:00 2001
From: Bart Feenstra <bart@mynameisbart.com>
Date: Fri, 6 Nov 2020 01:38:35 +0000
Subject: [PATCH 3/5] Remove profiling code.

---
 betty/cli.py | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/betty/cli.py b/betty/cli.py
index 3fc681326..e78d341cd 100644
--- a/betty/cli.py
+++ b/betty/cli.py
@@ -1,6 +1,4 @@
-import cProfile
 import logging
-import pstats
 import shutil
 import sys
 from contextlib import suppress, contextmanager
@@ -134,7 +132,5 @@ async def _clear_caches():
 @click.command(help='Generate a static site.')
 @site_command
 async def _generate(site: Site):
-    with cProfile.Profile() as pr:
-        await parse.parse(site)
-        await generate.generate(site)
-    pstats.Stats(pr).strip_dirs().sort_stats(pstats.SortKey.CUMULATIVE).print_stats()
+    await parse.parse(site)
+    await generate.generate(site)

From 2004843851f817b5798791f589e4d85482f0f1b1 Mon Sep 17 00:00:00 2001
From: Bart Feenstra <bart@mynameisbart.com>
Date: Tue, 10 Nov 2020 00:55:32 +0000
Subject: [PATCH 4/5] Compile template directories.

---
 .../resource-collection/event/index.json.j2   |   2 +-
 .../resource-collection/person/index.json.j2  |   2 +-
 .../resource-collection/place/index.json.j2   |   2 +-
 .../resource-collection/source/index.json.j2  |   2 +-
 .../templates/resource/citation/index.json.j2 |   2 +-
 .../templates/resource/event/index.json.j2    |   2 +-
 .../templates/resource/file/index.json.j2     |   2 +-
 .../templates/resource/person/index.json.j2   |   2 +-
 .../templates/resource/place/index.json.j2    |   2 +-
 .../templates/resource/source/index.json.j2   |   2 +-
 betty/fs.py                                   |  39 ++---
 betty/generate.py                             |  22 +--
 betty/jinja2.py                               |  37 +++--
 betty/plugin/maps/__init__.py                 |   2 +-
 betty/plugin/nginx/__init__.py                |   4 +-
 betty/plugin/trees/__init__.py                |   2 +-
 betty/render.py                               | 143 +++++++++++++++++-
 betty/sass.py                                 |  31 +++-
 betty/site.py                                 |   4 +-
 betty/tests/test_fs.py                        |  10 +-
 20 files changed, 236 insertions(+), 78 deletions(-)

diff --git a/betty/assets/templates/resource-collection/event/index.json.j2 b/betty/assets/templates/resource-collection/event/index.json.j2
index 3bb10300d..b9bc12f6d 100644
--- a/betty/assets/templates/resource-collection/event/index.json.j2
+++ b/betty/assets/templates/resource-collection/event/index.json.j2
@@ -1,4 +1,4 @@
 {{ {
     '$schema': 'schema.json#/definitions/eventCollection' | static_url(absolute=True),
     'collection': file_resources | list,
-} | json }}
+} | json | safe }}
diff --git a/betty/assets/templates/resource-collection/person/index.json.j2 b/betty/assets/templates/resource-collection/person/index.json.j2
index cad0cf747..8c9061961 100644
--- a/betty/assets/templates/resource-collection/person/index.json.j2
+++ b/betty/assets/templates/resource-collection/person/index.json.j2
@@ -1,4 +1,4 @@
 {{ {
     '$schema': 'schema.json#/definitions/personCollection' | static_url(absolute=True),
     'collection': file_resources | list,
-} | json }}
+} | json | safe }}
diff --git a/betty/assets/templates/resource-collection/place/index.json.j2 b/betty/assets/templates/resource-collection/place/index.json.j2
index 99f8ec750..eef0e176b 100644
--- a/betty/assets/templates/resource-collection/place/index.json.j2
+++ b/betty/assets/templates/resource-collection/place/index.json.j2
@@ -1,4 +1,4 @@
 {{ {
     '$schema': 'schema.json#/definitions/placeCollection' | static_url(absolute=True),
     'collection': file_resources | list,
-} | json }}
+} | json | safe }}
diff --git a/betty/assets/templates/resource-collection/source/index.json.j2 b/betty/assets/templates/resource-collection/source/index.json.j2
index 1e58f601a..69c42ccce 100644
--- a/betty/assets/templates/resource-collection/source/index.json.j2
+++ b/betty/assets/templates/resource-collection/source/index.json.j2
@@ -1,4 +1,4 @@
 {{ {
     '$schema': 'schema.json#/definitions/sourceCollection' | static_url(absolute=True),
     'collection': file_resources | list,
-} | json }}
+} | json | safe }}
diff --git a/betty/assets/templates/resource/citation/index.json.j2 b/betty/assets/templates/resource/citation/index.json.j2
index e518d5120..1b8670df4 100644
--- a/betty/assets/templates/resource/citation/index.json.j2
+++ b/betty/assets/templates/resource/citation/index.json.j2
@@ -1 +1 @@
-{{ file_resource | json }}
+{{ file_resource | json | safe }}
diff --git a/betty/assets/templates/resource/event/index.json.j2 b/betty/assets/templates/resource/event/index.json.j2
index e518d5120..1b8670df4 100644
--- a/betty/assets/templates/resource/event/index.json.j2
+++ b/betty/assets/templates/resource/event/index.json.j2
@@ -1 +1 @@
-{{ file_resource | json }}
+{{ file_resource | json | safe }}
diff --git a/betty/assets/templates/resource/file/index.json.j2 b/betty/assets/templates/resource/file/index.json.j2
index e518d5120..1b8670df4 100644
--- a/betty/assets/templates/resource/file/index.json.j2
+++ b/betty/assets/templates/resource/file/index.json.j2
@@ -1 +1 @@
-{{ file_resource | json }}
+{{ file_resource | json | safe }}
diff --git a/betty/assets/templates/resource/person/index.json.j2 b/betty/assets/templates/resource/person/index.json.j2
index e518d5120..1b8670df4 100644
--- a/betty/assets/templates/resource/person/index.json.j2
+++ b/betty/assets/templates/resource/person/index.json.j2
@@ -1 +1 @@
-{{ file_resource | json }}
+{{ file_resource | json | safe }}
diff --git a/betty/assets/templates/resource/place/index.json.j2 b/betty/assets/templates/resource/place/index.json.j2
index e518d5120..1b8670df4 100644
--- a/betty/assets/templates/resource/place/index.json.j2
+++ b/betty/assets/templates/resource/place/index.json.j2
@@ -1 +1 @@
-{{ file_resource | json }}
+{{ file_resource | json | safe }}
diff --git a/betty/assets/templates/resource/source/index.json.j2 b/betty/assets/templates/resource/source/index.json.j2
index e518d5120..1b8670df4 100644
--- a/betty/assets/templates/resource/source/index.json.j2
+++ b/betty/assets/templates/resource/source/index.json.j2
@@ -1 +1 @@
-{{ file_resource | json }}
+{{ file_resource | json | safe }}
diff --git a/betty/fs.py b/betty/fs.py
index 5b2f4b939..25e7dc055 100644
--- a/betty/fs.py
+++ b/betty/fs.py
@@ -4,8 +4,8 @@
 from collections import deque
 from contextlib import suppress
 from os import walk, path
-from tempfile import mkdtemp, TemporaryDirectory
-from typing import Iterable
+from tempfile import mkdtemp
+from typing import Iterable, Dict
 
 
 def iterfiles(file_path: str) -> Iterable[str]:
@@ -22,7 +22,7 @@ def hashfile(file_path: str) -> str:
     return hashlib.md5(':'.join([str(path.getmtime(file_path)), file_path]).encode('utf-8')).hexdigest()
 
 
-async def copy_tree(source_path: str, destination_path: str):
+async def copy_directory(source_path: str, destination_path: str):
     for file_source_path in iterfiles(source_path):
         file_destination_path = path.join(destination_path, path.relpath(file_source_path, source_path))
         try:
@@ -32,23 +32,6 @@ async def copy_tree(source_path: str, destination_path: str):
             shutil.copy2(file_source_path, file_destination_path)
 
 
-class CopyTreeTo:
-    def __init__(self, file_system: 'FileSystem', source_path: str):
-        self._file_system = file_system
-        self._source_path = source_path
-
-    async def __aenter__(self) -> 'CopyTreeTo':
-        self._intermediate_directory = TemporaryDirectory()
-        await self._file_system.copy_tree(self._source_path, self._intermediate_directory.name)
-        return self
-
-    async def __call__(self, destination_path: str) -> None:
-        await copy_tree(self._intermediate_directory.name, destination_path)
-
-    async def __aexit__(self, exc_type, exc_val, exc_tb):
-        self._intermediate_directory.cleanup()
-
-
 class FileSystem:
     def __init__(self, *paths: str):
         """
@@ -60,7 +43,7 @@ def __init__(self, *paths: str):
     def paths(self) -> deque:
         return self._paths
 
-    async def copy(self, source_path: str, destination_path: str) -> None:
+    async def copy_file(self, source_path: str, destination_path: str) -> None:
         makedirs(path.dirname(destination_path))
 
         for fs_path in self._paths:
@@ -70,13 +53,13 @@ async def copy(self, source_path: str, destination_path: str) -> None:
         tried_paths = [path. join(fs_path, source_path) for fs_path in self._paths]
         raise FileNotFoundError('Could not find any of %s.' % ', '.join(tried_paths))
 
-    async def copy_tree(self, source_path: str, destination_path: str) -> None:
+    async def copy_directory(self, source_path: str, destination_path: str) -> None:
         makedirs(destination_path)
 
         tries = []
         for fs_path in reversed(self._paths):
             try:
-                await copy_tree(path.join(fs_path, source_path), destination_path)
+                await copy_directory(path.join(fs_path, source_path), destination_path)
                 tries.append(True)
             except FileNotFoundError:
                 tries.append(False)
@@ -85,8 +68,14 @@ async def copy_tree(self, source_path: str, destination_path: str) -> None:
             tried_paths = [path. join(fs_path, source_path) for fs_path in self._paths]
             raise FileNotFoundError('Could not find any of %s.' % ', '.join(tried_paths))
 
-    def copy_tree_to(self, source_path: str) -> CopyTreeTo:
-        return CopyTreeTo(self, source_path)
+    def iterfiles(self, directory_path: str) -> Dict[str, str]:
+        file_paths = {}
+        for fs_path in reversed(self._paths):
+            for dir_path, _, filenames in walk(directory_path):
+                for filename in filenames:
+                    file_path = path.join(dir_path, filename)
+                    file_paths[path.relpath(file_path, fs_path)] = file_path
+        return file_paths
 
 
 class DirectoryBackup:
diff --git a/betty/generate.py b/betty/generate.py
index 37247a166..6bb345a0b 100644
--- a/betty/generate.py
+++ b/betty/generate.py
@@ -2,6 +2,7 @@
 import os
 from json import dump
 from os import chmod, path
+from tempfile import TemporaryDirectory
 from typing import Iterable, Union
 
 from babel import Locale
@@ -26,9 +27,9 @@ async def post_generate(self) -> None:
 
 async def generate(site: Site) -> None:
     logger = logging.getLogger()
-    await site.assets.copy_tree(path.join('public', 'static'),
-                                site.configuration.www_directory_path)
-    await site.renderer.render_tree(site.configuration.www_directory_path)
+    await site.assets.copy_directory(path.join('public', 'static'),
+                                     site.configuration.www_directory_path)
+    await site.renderer.render_directory(site.configuration.www_directory_path)
     await site.dispatcher.dispatch(PostStaticGenerator, 'post_static_generate')()
     for locale, locale_configuration in site.configuration.locales.items():
         async with site.with_locale(locale) as site:
@@ -38,8 +39,8 @@ async def generate(site: Site) -> None:
             else:
                 www_directory_path = site.configuration.www_directory_path
 
-            await site.assets.copy_tree(path.join('public', 'localized'), www_directory_path)
-            await site.renderer.render_tree(www_directory_path)
+            await site.assets.copy_directory(path.join('public', 'localized'), www_directory_path)
+            await site.renderer.render_directory(www_directory_path)
 
             locale_label = Locale.parse(locale, '-').get_display_name()
             resources_by_type = {
@@ -68,18 +69,19 @@ async def generate(site: Site) -> None:
 async def _generate_resource_type(www_directory_path: str, resources: Iterable[IdentifiableResource], resource_type_name: str, site: Site) -> None:
     resources_template_directory_path = path.join('templates', 'resource-collection', resource_type_name)
     resources_destination_path = path.join(www_directory_path, resource_type_name)
-    await site.assets.copy_tree(resources_template_directory_path, resources_destination_path)
+    await site.assets.copy_directory(resources_template_directory_path, resources_destination_path)
     if path.exists(resources_destination_path):
-        await site.renderer.render_tree(resources_destination_path, {
+        await site.renderer.render_directory(resources_destination_path, {
             'file_resources': resources,
         })
 
     resource_template_directory_path = path.join('templates', 'resource', resource_type_name)
-    async with site.assets.copy_tree_to(resource_template_directory_path) as copy_tree_to:
+    with TemporaryDirectory() as intermediate_directory_path:
+        await site.assets.copy_directory(resource_template_directory_path, intermediate_directory_path)
+        render_directory_to = await site.renderer.render_directory_to(intermediate_directory_path)
         for resource in resources:
             resource_destination_path = path.join(www_directory_path, resource.resource_type_name, resource.id)
-            await copy_tree_to(resource_destination_path)
-            await site.renderer.render_tree(resource_destination_path, {
+            await render_directory_to(resource_destination_path, {
                 'file_resource': resource,
             })
 
diff --git a/betty/jinja2.py b/betty/jinja2.py
index 46ad7b092..ac3234bc3 100644
--- a/betty/jinja2.py
+++ b/betty/jinja2.py
@@ -36,7 +36,7 @@
 from betty.media_type import MediaType
 from betty.path import extension
 from betty.plugin import Plugin
-from betty.render import Renderer, RenderArguments
+from betty.render import Renderer, TemplateArguments
 from betty.search import Index
 from betty.site import Site
 
@@ -201,18 +201,33 @@ def _filter_url(context, resource, media_type=None, locale=None, **kwargs):
 
 
 class Jinja2Renderer(Renderer):
+    _EXTENSIONS = {'j2'}
+
     def __init__(self, environment: Environment, configuration: Configuration):
         self._environment = environment
         self._configuration = configuration
 
-    async def _render_file(self, file_path: str, file_arguments: RenderArguments = None) -> None:
-        if not file_path.endswith('.j2'):
-            return
+    def _assert_file_path(self, file_path: str) -> None:
+        if not self.consumes_file_path(file_path):
+            raise ValueError('Cannot consume "%s".' % file_path)
+
+    def consumes_file_path(self, file_path: str) -> bool:
+        return file_path.endswith('.j2')
+
+    def update_file_path(self, file_path: str) -> str:
+        self._assert_file_path(file_path)
+        return file_path[:-3]
+
+    async def render_string(self, template: str, template_arguments: TemplateArguments = None) -> str:
+        return await self._environment.from_string(template).render_async(**template_arguments)
+
+    async def render_file(self, file_path: str, template_arguments: TemplateArguments = None) -> None:
+        self._assert_file_path(file_path)
         file_destination_path = file_path[:-3]
         template = _root_loader.load(self._environment, file_path, self._environment.globals)
-        if file_arguments is None:
-            file_arguments = {}
-        if 'file_resource' not in file_arguments and file_destination_path.startswith(self._configuration.www_directory_path):
+        if template_arguments is None:
+            template_arguments = {}
+        if 'file_resource' not in template_arguments and file_destination_path.startswith(self._configuration.www_directory_path):
             # Unix-style paths use forward slashes, so they are valid URL paths.
             resource = file_destination_path[len(
                 self._configuration.www_directory_path):]
@@ -220,14 +235,14 @@ async def _render_file(self, file_path: str, file_arguments: RenderArguments = N
                 resource_parts = resource.lstrip('/').split('/')
                 if resource_parts[0] in map(lambda x: x.alias, self._configuration.locales.values()):
                     resource = '/'.join(resource_parts[1:])
-            file_arguments['file_resource'] = resource
+            template_arguments['file_resource'] = resource
         with open(file_destination_path, 'w') as f:
-            f.write(await template.render_async(**file_arguments))
+            f.write(await template.render_async(**template_arguments))
         os.remove(file_path)
 
-    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
+    async def render_directory(self, directory_path: str, template_arguments: TemplateArguments = None) -> None:
         await asyncio.gather(
-            *[self._render_file(file_path, file_arguments) for file_path in iterfiles(render_path)],
+            *[self.render_file(file_path, template_arguments) for file_path in iterfiles(directory_path) if self.consumes_file_path(file_path)],
         )
 
 
diff --git a/betty/plugin/maps/__init__.py b/betty/plugin/maps/__init__.py
index 757f482da..ed6b9dc81 100644
--- a/betty/plugin/maps/__init__.py
+++ b/betty/plugin/maps/__init__.py
@@ -37,7 +37,7 @@ async def _render(self) -> None:
             with suppress(FileNotFoundError):
                 shutil.rmtree(build_directory_path)
             shutil.copytree(path.join(self.assets_directory_path, 'js'), build_directory_path)
-        await self._site.renderer.render_tree(build_directory_path)
+        await self._site.renderer.render_directory(build_directory_path)
 
         self._site.executor.submit(_do_render, build_directory_path, self._site.configuration.www_directory_path)
 
diff --git a/betty/plugin/nginx/__init__.py b/betty/plugin/nginx/__init__.py
index 11a1343ba..ab9c44453 100644
--- a/betty/plugin/nginx/__init__.py
+++ b/betty/plugin/nginx/__init__.py
@@ -53,8 +53,8 @@ async def _generate_config(self) -> None:
         # Render the ngnix configuration.
         file_name = 'nginx.conf.j2'
         destination_file_path = os.path.join(output_directory_path, file_name)
-        await self._site.assets.copy(file_name, destination_file_path)
-        await self._site.renderer.render_tree(output_directory_path)
+        await self._site.assets.copy_file(file_name, destination_file_path)
+        await self._site.renderer.render_directory(output_directory_path)
 
         # Render the Dockerfile.
         copyfile(os.path.join(DOCKER_PATH, 'Dockerfile'), os.path.join(output_directory_path, 'Dockerfile'))
diff --git a/betty/plugin/trees/__init__.py b/betty/plugin/trees/__init__.py
index 5f2768e2b..611309cc2 100644
--- a/betty/plugin/trees/__init__.py
+++ b/betty/plugin/trees/__init__.py
@@ -37,7 +37,7 @@ async def _render(self) -> None:
             with suppress(FileNotFoundError):
                 shutil.rmtree(build_directory_path)
             shutil.copytree(path.join(self.assets_directory_path, 'js'), build_directory_path)
-        await self._site.renderer.render_tree(build_directory_path)
+        await self._site.renderer.render_directory(build_directory_path)
 
         self._site.executor.submit(_do_render, build_directory_path, self._site.configuration.www_directory_path)
 
diff --git a/betty/render.py b/betty/render.py
index 46ffd0e73..2ddc52379 100644
--- a/betty/render.py
+++ b/betty/render.py
@@ -1,17 +1,150 @@
-from typing import Optional, Dict, Any, Sequence
+from os import path
+from typing import Optional, Dict, Any, Sequence, Callable, Tuple, Awaitable, List
 
-RenderArguments = Optional[Dict[str, Any]]
+from betty.fs import iterfiles, makedirs
+
+_Pipeline = Sequence[Callable]
+_PipelineKwargs = Dict
+_Pipe = Callable[[_PipelineKwargs], Awaitable[_PipelineKwargs]]
+TemplateArguments = Optional[Dict[str, Any]]
+
+
+class SequentialRenderDirectoryTo:
+    def __init__(self, renderers: Sequence['Renderer'], source_directory_path: str):
+        self._renderers = renderers
+        self._source_directory_path = source_directory_path
+        self._pipelines = []
+        self._initialized = False
+
+    async def __call__(self, destination_directory_path: str, template_arguments: TemplateArguments = None) -> None:
+        await self._build_pipelines()
+        for pipeline, initial_pipeline_kwargs in self._pipelines:
+            pipeline_kwargs = initial_pipeline_kwargs.copy()
+            pipeline_kwargs['destination_directory_path'] = destination_directory_path
+            await self._execute_pipeline(pipeline, pipeline_kwargs, template_arguments)
+
+    async def _execute_pipeline(self, pipeline, pipeline_kwargs, template_arguments: TemplateArguments) -> None:
+        pipeline_kwargs['template_arguments'] = template_arguments
+        for pipe in pipeline:
+            pipeline_kwargs = await pipe(pipeline_kwargs)
+
+    async def _build_pipelines(self):
+        if self._initialized:
+            return
+        self._initialized = True
+
+        for file_path in iterfiles(self._source_directory_path):
+            self._pipelines.append(await self._build_pipeline(file_path, self._collect_renderers(file_path)))
+
+    def _collect_renderers(self, file_path: str) -> List['Renderer']:
+        for renderer in self._renderers:
+            if renderer.consumes_file_path(file_path):
+                return [renderer] + self._collect_renderers(renderer.update_file_path(file_path))
+        return []
+
+    async def _build_pipeline(self, file_path: str, renderers: Sequence['Renderer']) -> Tuple[_Pipeline, _PipelineKwargs]:
+        initial_pipeline_kwargs = {
+            'file_path': file_path,
+            'destination_directory_path': None,
+            'template': None,
+            'bytes': None,
+            'template_arguments': {},
+        }
+        if renderers:
+            initial_pipeline_kwargs = await self._render_file_to_string()(initial_pipeline_kwargs)
+            pipeline = []
+            for renderer in renderers:
+                pipeline.append(self._render_string(renderer))
+            pipeline.append(self._render_string_to_file())
+        else:
+            initial_pipeline_kwargs = await self._render_file_to_bytes()(initial_pipeline_kwargs)
+            pipeline = [lambda pipeline_kwargs: self._render_bytes_to_file()]
+
+        return pipeline, initial_pipeline_kwargs
+
+    def _render_string(self, renderer: 'Renderer') -> _Pipe:
+        async def _render(pipeline_kwargs: _PipelineKwargs) -> _PipelineKwargs:
+            pipeline_kwargs['file_path'] = renderer.update_file_path(pipeline_kwargs['file_path'])
+            pipeline_kwargs['template'] = await renderer.render_string(template=pipeline_kwargs['template'], template_arguments=pipeline_kwargs['template_arguments'])
+            return pipeline_kwargs
+        return _render
+
+    def _render_file_to_string(self) -> _Pipe:
+        async def _render(pipeline_kwargs: _PipelineKwargs) -> _PipelineKwargs:
+            with open(pipeline_kwargs['file_path']) as f:
+                pipeline_kwargs['template'] = f.read()
+            return pipeline_kwargs
+        return _render
+
+    def _render_string_to_file(self) -> _Pipe:
+        async def _render(pipeline_kwargs: _PipelineKwargs) -> _PipelineKwargs:
+            destination_file_path = path.join(pipeline_kwargs['destination_directory_path'], path.relpath(pipeline_kwargs['file_path'], self._source_directory_path))
+            makedirs(path.dirname(destination_file_path))
+            with open(destination_file_path, 'w') as f:
+                f.write(pipeline_kwargs['template'])
+            return pipeline_kwargs
+        return _render
+
+    def _render_file_to_bytes(self) -> _Pipe:
+        async def _render(pipeline_kwargs: _PipelineKwargs) -> _PipelineKwargs:
+            with open(pipeline_kwargs['file_path'], 'rb') as f:
+                pipeline_kwargs['bytes'] = f.read()
+            return pipeline_kwargs
+        return _render
+
+    def _render_bytes_to_file(self) -> _Pipe:
+        async def _render(pipeline_kwargs: _PipelineKwargs) -> _PipelineKwargs:
+            destination_file_path = path.join(pipeline_kwargs['destination_directory_path'], path.relpath(pipeline_kwargs['file_path'], self._source_directory_path))
+            makedirs(path.dirname(destination_file_path))
+            with open(destination_file_path, 'wb') as f:
+                f.write(pipeline_kwargs['bytes'])
+            return pipeline_kwargs
+        return _render
 
 
 class Renderer:
-    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
+    async def render_string(self, template: str, template_arguments: TemplateArguments = None) -> str:
+        raise NotImplementedError
+
+    def consumes_file_path(self, file_path: str) -> bool:
+        raise NotImplementedError
+
+    def update_file_path(self, file_path: str) -> str:
+        """
+        Update a file path as if it has been rendered by this renderer.
+        """
+        raise NotImplementedError
+
+    async def render_file(self, file_path: str, template_arguments: TemplateArguments = None) -> None:
+        raise NotImplementedError
+
+    async def render_directory(self, directory_path: str, template_arguments: TemplateArguments = None) -> None:
         raise NotImplementedError
 
+    async def render_directory_to(self, directory_path: str) -> SequentialRenderDirectoryTo:
+        return SequentialRenderDirectoryTo([self], directory_path)
+
 
 class SequentialRenderer(Renderer):
     def __init__(self, renderers: Sequence[Renderer]):
         self._renderers = renderers
 
-    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
+    def consumes_file_path(self, file_path: str) -> bool:
+        return True
+
+    def update_file_path(self, file_path: str) -> str:
+        for renderer in self._renderers:
+            if renderer.consumes_file_path(file_path):
+                file_path = renderer.update_file_path(file_path)
+        return file_path
+
+    async def render_file(self, file_path: str, template_arguments: TemplateArguments = None) -> None:
+        for renderer in self._renderers:
+            await renderer.render_file(file_path, template_arguments)
+
+    async def render_directory(self, directory_path: str, template_arguments: TemplateArguments = None) -> None:
         for renderer in self._renderers:
-            await renderer.render_tree(render_path, file_arguments)
+            await renderer.render_directory(directory_path, template_arguments)
+
+    async def render_directory_to(self, directory_path: str) -> SequentialRenderDirectoryTo:
+        return SequentialRenderDirectoryTo(self._renderers, directory_path)
diff --git a/betty/sass.py b/betty/sass.py
index 74be782b7..1464e8d95 100644
--- a/betty/sass.py
+++ b/betty/sass.py
@@ -3,20 +3,39 @@
 
 import sass
 
-from betty.render import Renderer, RenderArguments
+from betty.render import Renderer, TemplateArguments
 
 
 class SassRenderer(Renderer):
-    _EXTENSIONS = ('sass', 'scss')
+    _EXTENSIONS = {'sass', 'scss'}
 
-    async def render_tree(self, render_path: str, file_arguments: RenderArguments = None) -> None:
-        sass.compile(dirname=(render_path, render_path))
+    def _assert_file_path(self, file_path: str) -> None:
+        if not self.consumes_file_path(file_path):
+            raise ValueError('Cannot consume "%s".' % file_path)
+
+    def consumes_file_path(self, file_path: str) -> bool:
+        return file_path.endswith(tuple(self._EXTENSIONS))
+
+    def update_file_path(self, file_path: str) -> str:
+        self._assert_file_path(file_path)
+        return file_path[:-3]
+
+    async def render_string(self, template: str, template_arguments: TemplateArguments = None) -> str:
+        return sass.compile(string=template)
+
+    async def render_file(self, file_path: str, file_arguments: TemplateArguments = None) -> None:
+        self._assert_file_path(file_path)
+        sass.compile(filename=(file_path, file_path))
+        os.remove(file_path)
+
+    async def render_directory(self, directory_path: str, file_arguments: TemplateArguments = None) -> None:
+        sass.compile(dirname=(directory_path, directory_path))
         for extension in self._EXTENSIONS:
             patterns = [
                 # Files in the path.
-                os.path.join(render_path, '*.' + extension),
+                os.path.join(directory_path, '*.' + extension),
                 # Files in the path's subdirectories.
-                os.path.join(render_path, '**', '*.' + extension),
+                os.path.join(directory_path, '**', '*.' + extension),
             ]
             for pattern in patterns:
                 for file_path in glob(pattern):
diff --git a/betty/site.py b/betty/site.py
index e8aeb9786..751622784 100644
--- a/betty/site.py
+++ b/betty/site.py
@@ -8,7 +8,7 @@
 from betty.concurrent import ExceptionRaisingExecutor
 from betty.dispatch import Dispatcher
 from betty.lock import Locks
-from betty.render import Renderer, SequentialRenderer
+from betty.render import SequentialRenderer
 from betty.sass import SassRenderer
 
 try:
@@ -178,7 +178,7 @@ def jinja2_environment(self) -> Environment:
         return self._jinja2_environment
 
     @property
-    def renderer(self) -> Renderer:
+    def renderer(self) -> SequentialRenderer:
         if not self._renderer:
             from betty.jinja2 import Jinja2Renderer
             self._renderer = SequentialRenderer([
diff --git a/betty/tests/test_fs.py b/betty/tests/test_fs.py
index 34e913a97..d563b9a50 100644
--- a/betty/tests/test_fs.py
+++ b/betty/tests/test_fs.py
@@ -57,9 +57,9 @@ async def test_copy(self):
                 with TemporaryDirectory() as destination_path:
                     sut = FileSystem(source_path_1, source_path_2)
 
-                    await sut.copy('apples', join(destination_path, 'apples'))
-                    await sut.copy('oranges', join(destination_path, 'oranges'))
-                    await sut.copy('bananas', join(destination_path, 'bananas'))
+                    await sut.copy_file('apples', join(destination_path, 'apples'))
+                    await sut.copy_file('oranges', join(destination_path, 'oranges'))
+                    await sut.copy_file('bananas', join(destination_path, 'bananas'))
 
                     with open(join(destination_path, 'apples')) as f:
                         self.assertEquals('apples', f.read())
@@ -69,7 +69,7 @@ async def test_copy(self):
                         self.assertEquals('bananas', f.read())
 
                     with self.assertRaises(FileNotFoundError):
-                        await sut.copy('mangos', destination_path)
+                        await sut.copy_file('mangos', destination_path)
 
     @sync
     async def test_copy_tree(self):
@@ -89,7 +89,7 @@ async def test_copy_tree(self):
                 with TemporaryDirectory() as destination_path:
                     sut = FileSystem(source_path_1, source_path_2)
 
-                    await sut.copy_tree('', destination_path)
+                    await sut.copy_directory('', destination_path)
 
                     with open(join(destination_path, 'basket', 'apples')) as f:
                         self.assertEquals('apples', f.read())

From 1866bfee028280f871b2cf1d8a74ccca938e0b31 Mon Sep 17 00:00:00 2001
From: Bart Feenstra <bart@mynameisbart.com>
Date: Wed, 11 Nov 2020 22:42:08 +0000
Subject: [PATCH 5/5] Try and make Jinja2 rendering sync to see if that reduces
 overhead. MASSIVE STASH DOES NOT WORK.

---
 betty/cli.py                                  |  8 +++--
 betty/functools.py                            | 15 +++------
 betty/jinja2.py                               | 33 ++++++++++---------
 .../assets/public/localized/people.json.j2    |  4 +--
 betty/plugin/wikipedia/__init__.py            |  2 ++
 betty/search.py                               | 15 +++++----
 6 files changed, 40 insertions(+), 37 deletions(-)

diff --git a/betty/cli.py b/betty/cli.py
index e78d341cd..3fc681326 100644
--- a/betty/cli.py
+++ b/betty/cli.py
@@ -1,4 +1,6 @@
+import cProfile
 import logging
+import pstats
 import shutil
 import sys
 from contextlib import suppress, contextmanager
@@ -132,5 +134,7 @@ async def _clear_caches():
 @click.command(help='Generate a static site.')
 @site_command
 async def _generate(site: Site):
-    await parse.parse(site)
-    await generate.generate(site)
+    with cProfile.Profile() as pr:
+        await parse.parse(site)
+        await generate.generate(site)
+    pstats.Stats(pr).strip_dirs().sort_stats(pstats.SortKey.CUMULATIVE).print_stats()
diff --git a/betty/functools.py b/betty/functools.py
index 6c4d0b730..e87a8a1a4 100644
--- a/betty/functools.py
+++ b/betty/functools.py
@@ -22,18 +22,13 @@ def walk(item, attribute_name):
         yield from walk(child, attribute_name)
 
 
-async def asynciter(items: Union[Iterable, AsyncIterable]) -> AsyncIterable:
-    if hasattr(items, '__aiter__'):
-        async for item in items:
-            yield item
-        return
-    for item in items:
-        yield item
-
-
 def sync(f):
     if iscoroutine(f):
-        return asyncio.get_event_loop().run_until_complete(f)
+        try:
+            loop = asyncio.get_running_loop()
+        except RuntimeError:
+            loop = asyncio.get_event_loop()
+        return loop.run_until_complete(f)
     elif iscoroutinefunction(f):
         @wraps(f)
         def _synced(*args, **kwargs):
diff --git a/betty/jinja2.py b/betty/jinja2.py
index ac3234bc3..d1f68ad8c 100644
--- a/betty/jinja2.py
+++ b/betty/jinja2.py
@@ -16,7 +16,6 @@
 from geopy import units
 from geopy.format import DEGREES_FORMAT
 from jinja2 import Environment, select_autoescape, evalcontextfilter, escape, FileSystemLoader, contextfilter, Template
-from jinja2.asyncsupport import auto_await
 from jinja2.filters import prepare_map, make_attrgetter
 from jinja2.runtime import Macro, resolve_or_missing, StrictUndefined
 from jinja2.utils import htmlsafe_json_dumps
@@ -27,7 +26,6 @@
     RESOURCE_TYPES
 from betty.config import Configuration
 from betty.fs import makedirs, hashfile, iterfiles
-from betty.functools import walk, asynciter
 from betty.html import HtmlProvider
 from betty.importlib import import_any
 from betty.json import JSONEncoder
@@ -96,7 +94,7 @@ def __init__(self, site: Site):
         template_directory_paths = [join(path, 'templates') for path in site.assets.paths]
 
         Environment.__init__(self,
-                             enable_async=True,
+                             # enable_async=True,
                              loader=FileSystemLoader(template_directory_paths),
                              undefined=StrictUndefined,
                              autoescape=select_autoescape(['html']),
@@ -219,7 +217,7 @@ def update_file_path(self, file_path: str) -> str:
         return file_path[:-3]
 
     async def render_string(self, template: str, template_arguments: TemplateArguments = None) -> str:
-        return await self._environment.from_string(template).render_async(**template_arguments)
+        return self._environment.from_string(template).render(**template_arguments)
 
     async def render_file(self, file_path: str, template_arguments: TemplateArguments = None) -> None:
         self._assert_file_path(file_path)
@@ -237,18 +235,21 @@ async def render_file(self, file_path: str, template_arguments: TemplateArgument
                     resource = '/'.join(resource_parts[1:])
             template_arguments['file_resource'] = resource
         with open(file_destination_path, 'w') as f:
-            f.write(await template.render_async(**template_arguments))
+            f.write(template.render(**template_arguments))
         os.remove(file_path)
 
     async def render_directory(self, directory_path: str, template_arguments: TemplateArguments = None) -> None:
-        await asyncio.gather(
-            *[self.render_file(file_path, template_arguments) for file_path in iterfiles(directory_path) if self.consumes_file_path(file_path)],
-        )
+        # await asyncio.gather(
+        #     *[self.render_file(file_path, template_arguments) for file_path in iterfiles(directory_path) if self.consumes_file_path(file_path)],
+        # )
+        for file_path in iterfiles(directory_path):
+            if self.consumes_file_path(file_path):
+                await self.render_file(file_path, template_arguments)
 
 
-async def _filter_flatten(items):
-    async for item in asynciter(items):
-        async for child in asynciter(item):
+def _filter_flatten(items):
+    for item in items:
+        for child in item:
             yield child
 
 
@@ -286,18 +287,18 @@ def _filter_format_degrees(degrees):
 
 
 @contextfilter
-async def _filter_map(*args, **kwargs):
+def _filter_map(*args, **kwargs):
     if len(args) == 3 and isinstance(args[2], Macro):
         seq = args[1]
         func = args[2]
     else:
         seq, func = prepare_map(args, kwargs)
     if seq:
-        async for item in asynciter(seq):
-            yield await auto_await(func(item))
+        for item in seq:
+            yield func(item)
 
 
-async def _filter_file(site: Site, file: File) -> str:
+def _filter_file(site: Site, file: File) -> str:
     file_directory_path = os.path.join(site.configuration.www_directory_path, 'file')
 
     destination_name = '%s.%s' % (file.id, file.extension)
@@ -316,7 +317,7 @@ def _do_filter_file(file_path: str, destination_directory_path: str, destination
     os.link(file_path, destination_file_path)
 
 
-async def _filter_image(site: Site, file: File, width: Optional[int] = None, height: Optional[int] = None) -> str:
+def _filter_image(site: Site, file: File, width: Optional[int] = None, height: Optional[int] = None) -> str:
     if width is None and height is None:
         raise ValueError('At least the width or height must be given.')
 
diff --git a/betty/plugin/trees/assets/public/localized/people.json.j2 b/betty/plugin/trees/assets/public/localized/people.json.j2
index 437ee5c67..f676f8a7d 100644
--- a/betty/plugin/trees/assets/public/localized/people.json.j2
+++ b/betty/plugin/trees/assets/public/localized/people.json.j2
@@ -10,8 +10,8 @@
             'id': person.id,
             'label': person_label | striptags,
             'url': person | url,
-            'parentIds': person.parents | map(attribute='id') | list,
-            'childIds': person.children | map(attribute='id') | list,
+            'parentIds': person.parents | list,
+            'childIds': person.children | list,
         }
     }) %}
 {% endfor %}
diff --git a/betty/plugin/wikipedia/__init__.py b/betty/plugin/wikipedia/__init__.py
index 52542bae5..ea470cfbd 100644
--- a/betty/plugin/wikipedia/__init__.py
+++ b/betty/plugin/wikipedia/__init__.py
@@ -15,6 +15,7 @@
 
 from betty.ancestry import Link, HasLinks, Resource
 from betty.fs import makedirs
+from betty.functools import sync
 from betty.jinja2 import Jinja2Provider
 from betty.locale import Localized, negotiate_locale
 from betty.parse import PostParser
@@ -227,6 +228,7 @@ def filters(self) -> Dict[str, Callable]:
         }
 
     @contextfilter
+    @sync
     async def _filter_wikipedia_links(self, context, links: Iterable[Link]) -> Iterable[Entry]:
         locale = parse_locale(resolve_or_missing(context, 'locale'), '-')[0]
         return filter(None, await asyncio.gather(*[self._filter_wikipedia_link(locale, link) for link in links]))
diff --git a/betty/search.py b/betty/search.py
index 80a1732f3..86f92177b 100644
--- a/betty/search.py
+++ b/betty/search.py
@@ -9,15 +9,16 @@ class Index:
     def __init__(self, site: Site):
         self._site = site
 
-    async def build(self) -> Iterable[Dict]:
-        return filter(None, await asyncio.gather(*[
-            *[self._build_person(person) for person in self._site.ancestry.people.values()],
-            *[self._build_place(place) for place in self._site.ancestry.places.values()],
-            *[self._build_file(file) for file in self._site.ancestry.files.values()],
-        ]))
+    def build(self) -> Iterable[Dict]:
+        return [{}]
+        # return filter(None, await asyncio.gather(*[
+        #     *[self._build_person(person) for person in self._site.ancestry.people.values()],
+        #     *[self._build_place(place) for place in self._site.ancestry.places.values()],
+        #     *[self._build_file(file) for file in self._site.ancestry.files.values()],
+        # ]))
 
     async def _render_resource(self, resource: Resource):
-        return await self._site.jinja2_environment.get_template('search/result-%s.html.j2' % resource.resource_type_name).render_async({
+        return self._site.jinja2_environment.get_template('search/result-%s.html.j2' % resource.resource_type_name).render({
             resource.resource_type_name: resource,
         })