frontend/extension-config: allow default json files in a .d directory

notebook/auth/__main__.py

@@ -1,6 +1,6 @@
 from notebook.auth import passwd
 from getpass import getpass
-from traitlets.config.manager import BaseJSONConfigManager
+from notebook.manager import BaseJSONConfigManager
 from jupyter_core.paths import jupyter_config_dir
 import argparse
 import sys

notebook/bundler/bundlerextensions.py

@@ -5,10 +5,10 @@
 
 from ..extensions import BaseExtensionApp, _get_config_dir, GREEN_ENABLED, RED_DISABLED
 from .._version import __version__
+from notebook.manager import BaseJSONConfigManager
 
 from jupyter_core.paths import jupyter_config_path
 
-from traitlets.config.manager import BaseJSONConfigManager
 from traitlets.utils.importstring import import_item
 from traitlets import Bool
 

notebook/bundler/tests/test_bundlerextension.py

@@ -15,10 +15,10 @@
 from ipython_genutils.tempdir import TemporaryDirectory
 from ipython_genutils import py3compat
 
-from traitlets.config.manager import BaseJSONConfigManager
 from traitlets.tests.utils import check_help_all_output
 
 import notebook.nbextensions as nbextensions
+from notebook.manager import BaseJSONConfigManager
 from ..bundlerextensions import (_get_config_dir, enable_bundler_python, 
     disable_bundler_python)
 

notebook/manager.py

@@ -0,0 +1,103 @@
+"""Manager to read and modify config data in JSON files.
+"""
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+import errno
+import glob
+import io
+import json
+import os
+
+from six import PY3
+from traitlets.config import LoggingConfigurable
+from traitlets.traitlets import Unicode, Bool
+
+
+def recursive_update(target, new):
+    """Recursively update one dictionary using another.
+
+    None values will delete their keys.
+    """
+    for k, v in new.items():
+        if isinstance(v, dict):
+            if k not in target:
+                target[k] = {}
+            recursive_update(target[k], v)
+            if not target[k]:
+                # Prune empty subdicts
+                del target[k]
+
+        elif v is None:
+            target.pop(k, None)
+
+        else:
+            target[k] = v
+
+
+class BaseJSONConfigManager(LoggingConfigurable):
+    """General JSON config manager
+
+    Deals with persisting/storing config in a json file with optionally
+    default values in a {section_name}.d directory.
+    """
+
+    config_dir = Unicode('.')
+    read_directory = Bool(True)
+
+    def ensure_config_dir_exists(self):
+        try:
+            os.makedirs(self.config_dir, 0o755)
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+
+    def file_name(self, section_name):
+        return os.path.join(self.config_dir, section_name+'.json')
+
+    def directory(self, section_name):
+        return os.path.join(self.config_dir, section_name+'.d')
+
+    def get(self, section_name):
+        """Retrieve the config data for the specified section.
+
+        Returns the data as a dictionary, or an empty dictionary if the file
+        doesn't exist.
+        """
+        paths = [self.file_name(section_name)]
+        if self.read_directory:
+            pattern = os.path.join(self.directory(section_name), '*.json')
+            # These json files should be processed first so that the
+            # {section_name}.json take precedence.
+            # The idea behind this is that installing a Python package may
+            # put a json file somewhere in the a .d directory, while the 
+            # .json file is probably a user configuration.
+            paths = sorted(glob.glob(pattern)) + paths
+        data = {}
+        for path in paths:
+            if os.path.isfile(path):
+                with io.open(path, encoding='utf-8') as f:
+                    recursive_update(data, json.load(f))
+        return data
+
+    def set(self, section_name, data):
+        """Store the given config data.
+        """
+        filename = self.file_name(section_name)
+        self.ensure_config_dir_exists()
+
+        if PY3:
+            f = io.open(filename, 'w', encoding='utf-8')
+        else:
+            f = open(filename, 'wb')
+        with f:
+            json.dump(data, f, indent=2)
+
+    def update(self, section_name, new_data):
+        """Modify the config section by recursively updating it with new_data.
+
+        Returns the modified config data as a dictionary.
+        """
+        data = self.get(section_name)
+        recursive_update(data, new_data)
+        self.set(section_name, data)
+        return data

notebook/nbextensions.py

@@ -29,7 +29,7 @@
 from ipython_genutils.tempdir import TemporaryDirectory
 from ._version import __version__
 
-from traitlets.config.manager import BaseJSONConfigManager
+from notebook.manager import BaseJSONConfigManager
 from traitlets.utils.importstring import import_item
 
 DEPRECATED_ARGUMENT = object()

notebook/serverextensions.py

@@ -16,7 +16,7 @@
 )
 from traitlets import Bool
 from traitlets.utils.importstring import import_item
-from traitlets.config.manager import BaseJSONConfigManager
+from notebook.manager import BaseJSONConfigManager
 
 
 # ------------------------------------------------------------------------------

notebook/services/config/manager.py

@@ -5,7 +5,7 @@
 
 import os.path
 
-from traitlets.config.manager import BaseJSONConfigManager, recursive_update
+from notebook.manager import BaseJSONConfigManager, recursive_update
 from jupyter_core.paths import jupyter_config_dir, jupyter_config_path
 from traitlets import Unicode, Instance, List, observe, default
 from traitlets.config import LoggingConfigurable

notebook/tests/test_manager.py

@@ -0,0 +1,39 @@
+import json
+import os
+import shutil
+import tempfile
+
+from notebook.manager import BaseJSONConfigManager
+
+
+def test_json():
+    tmpdir = tempfile.mkdtemp()
+    try:
+        with open(os.path.join(tmpdir, 'foo.json'), 'w') as f:
+            json.dump(dict(a=1), f)
+        # also make a foo.d/ directory with multiple json files
+        os.makedirs(os.path.join(tmpdir, 'foo.d'))
+        with open(os.path.join(tmpdir, 'foo.d', 'a.json'), 'w') as f:
+            json.dump(dict(a=2, b=1), f)
+        with open(os.path.join(tmpdir, 'foo.d', 'b.json'), 'w') as f:
+            json.dump(dict(a=3, b=2, c=3), f)
+        manager = BaseJSONConfigManager(config_dir=tmpdir, read_directory=False)
+        data = manager.get('foo')
+        assert 'a' in data
+        assert 'b' not in data
+        assert 'c' not in data
+        assert data['a'] == 1
+
+        manager = BaseJSONConfigManager(config_dir=tmpdir, read_directory=True)
+        data = manager.get('foo')
+        assert 'a' in data
+        assert 'b' in data
+        assert 'c' in data
+        # files should be read in order foo.d/a.json foo.d/b.json foo.json
+        assert data['a'] == 1
+        assert data['b'] == 2
+        assert data['c'] == 3
+    finally:
+        shutil.rmtree(tmpdir)
+
+

notebook/tests/test_nbextensions.py

@@ -30,7 +30,7 @@
     validate_nbextension, validate_nbextension_python
 )
 
-from traitlets.config.manager import BaseJSONConfigManager
+from notebook.manager import BaseJSONConfigManager
 
 
 def touch(file_name, mtime=None):

notebook/tests/test_serverextensions.py

@@ -10,7 +10,7 @@
 from ipython_genutils.tempdir import TemporaryDirectory
 from ipython_genutils import py3compat
 
-from traitlets.config.manager import BaseJSONConfigManager
+from notebook.manager import BaseJSONConfigManager
 from traitlets.tests.utils import check_help_all_output
 from jupyter_core import paths