index.html is not reliably loaded from a plugin

[simonw]

Lots of detail in simonw/datasette-search-all#2 - short version is that I have a plugin with its own index.html template and Datasette intermittently fails to load it and uses the default index.html that ships with Datasette instead.

Related:

• "Templates considered" comment broken in >=0.35 #689: "Templates considered" comment broken in >=0.35
• Variables from extra_template_vars() not exposed in _context=1 #693: Variables from extra_template_vars() not exposed in _context=1 (may as well fix this while I'm in there)

[simonw]

I think the bug is in this code:

datasette/datasette/app.py

Lines 612 to 623 in 7508477

	default_templates = str(app_root / "datasette" / "templates")
	template_paths = []
	if self.template_dir:
	template_paths.append(self.template_dir)
	template_paths.extend(
	[
	plugin["templates_path"]
	for plugin in get_plugins(pm)
	if plugin["templates_path"]
	]
	)
	template_paths.append(default_templates)

I added some debug logging to it and found that the bit that returns the plugin["templates_path"] list is producing this:

plugin_template_paths: [
  '/Users/simonw/Dropbox/Development/datasette/datasette/templates',
  '/Users/simonw/Dropbox/Development/datasette/datasette/templates',
  '/Users/simonw/Dropbox/Development/datasette-search-all/datasette_search_all/templates'
]

[simonw]

More debugging code shows this:

[
    (
        {
            "name": "datasette.facets",
            "static_path": "/Users/simonw/Dropbox/Development/datasette/datasette/static",
            "templates_path": "/Users/simonw/Dropbox/Development/datasette/datasette/templates",
        },
        "/Users/simonw/Dropbox/Development/datasette/datasette/templates",
    ),
    (
        {
            "name": "datasette.sql_functions",
            "static_path": "/Users/simonw/Dropbox/Development/datasette/datasette/static",
            "templates_path": "/Users/simonw/Dropbox/Development/datasette/datasette/templates",
        },
        "/Users/simonw/Dropbox/Development/datasette/datasette/templates",
    ),
    (
        {
            "name": "datasette-search-all",
            "static_path": None,
            "templates_path": "/Users/simonw/Dropbox/Development/datasette-search-all/datasette_search_all/templates",
            "version": "0.1",
        },
        "/Users/simonw/Dropbox/Development/datasette-search-all/datasette_search_all/templates",
    ),
]

So the problem is that the default plugins that ship with Datasette are adding a template path to the lookup list!

[simonw]

I think the bug is in this code:

datasette/datasette/utils/__init__.py

Lines 619 to 645 in 7508477

	def get_plugins(pm):
	plugins = []
	plugin_to_distinfo = dict(pm.list_plugin_distinfo())
	for plugin in pm.get_plugins():
	static_path = None
	templates_path = None
	try:
	if pkg_resources.resource_isdir(plugin.__name__, "static"):
	static_path = pkg_resources.resource_filename(plugin.__name__, "static")
	if pkg_resources.resource_isdir(plugin.__name__, "templates"):
	templates_path = pkg_resources.resource_filename(
	plugin.__name__, "templates"
	)
	except (KeyError, ImportError):
	# Caused by --plugins_dir= plugins - KeyError/ImportError thrown in Py3.5
	pass
	plugin_info = {
	"name": plugin.__name__,
	"static_path": static_path,
	"templates_path": templates_path,
	}
	distinfo = plugin_to_distinfo.get(plugin)
	if distinfo:
	plugin_info["version"] = distinfo.version
	plugin_info["name"] = distinfo.project_name
	plugins.append(plugin_info)
	return plugins

[simonw]

I need that code to set static_path and templates_path to None for plugins that ship as part of Datasette.

[simonw]

I'm going to release this as 0.37.2.

This is the first time I've released a version NOT from master (since I don't want to ship the --memory feature for Cloud Run until 0.38 - #694). So I've cut a v0.37.2 release branch instead.

[simonw]

Cancel that plan: I'm pretty sure the Travis configuration that publishes a demo to Zeit Now and builds a Docker image isn't designed to handle releases that don't correspond to current master. I guess I'll release 0.38 instead.

[simonw]

Shipped in Datasette 0.38.