1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
.. _contents_api:
Contents API
============
.. currentmodule:: notebook.services.contents
The Jupyter Notebook web application provides a graphical interface for
creating, opening, renaming, and deleting files in a virtual filesystem.
The :class:`~manager.ContentsManager` class defines an abstract
API for translating these interactions into operations on a particular storage
medium. The default implementation,
:class:`~filemanager.FileContentsManager`, uses the local
filesystem of the server for storage and straightforwardly serializes notebooks
into JSON. Users can override these behaviors by supplying custom subclasses
of ContentsManager.
This section describes the interface implemented by ContentsManager subclasses.
We refer to this interface as the **Contents API**.
Data Model
----------
.. currentmodule:: notebook.services.contents.manager
Filesystem Entities
~~~~~~~~~~~~~~~~~~~
.. _notebook models:
ContentsManager methods represent virtual filesystem entities as dictionaries,
which we refer to as **models**.
Models may contain the following entries:
+--------------------+-----------+------------------------------+
| Key | Type |Info |
+====================+===========+==============================+
|**name** |unicode |Basename of the entity. |
+--------------------+-----------+------------------------------+
|**path** |unicode |Full |
| | |(:ref:`API-style<apipaths>`) |
| | |path to the entity. |
+--------------------+-----------+------------------------------+
|**type** |unicode |The entity type. One of |
| | |``"notebook"``, ``"file"`` or |
| | |``"directory"``. |
+--------------------+-----------+------------------------------+
|**created** |datetime |Creation date of the entity. |
+--------------------+-----------+------------------------------+
|**last_modified** |datetime |Last modified date of the |
| | |entity. |
+--------------------+-----------+------------------------------+
|**content** |variable |The "content" of the entity. |
| | |(:ref:`See |
| | |Below<modelcontent>`) |
+--------------------+-----------+------------------------------+
|**mimetype** |unicode or |The mimetype of ``content``, |
| |``None`` |if any. (:ref:`See |
| | |Below<modelcontent>`) |
+--------------------+-----------+------------------------------+
|**format** |unicode or |The format of ``content``, |
| |``None`` |if any. (:ref:`See |
| | |Below<modelcontent>`) |
+--------------------+-----------+------------------------------+
.. _modelcontent:
Certain model fields vary in structure depending on the ``type`` field of the
model. There are three model types: **notebook**, **file**, and **directory** .
- ``notebook`` models
- The ``format`` field is always ``"json"``.
- The ``mimetype`` field is always ``None``.
- The ``content`` field contains a
:class:`nbformat.notebooknode.NotebookNode` representing the .ipynb file
represented by the model. See the `NBFormat`_ documentation for a full
description.
- ``file`` models
- The ``format`` field is either ``"text"`` or ``"base64"``.
- The ``mimetype`` field is ``text/plain`` for text-format models and
``application/octet-stream`` for base64-format models.
- The ``content`` field is always of type ``unicode``. For text-format
file models, ``content`` simply contains the file's bytes after decoding
as UTF-8. Non-text (``base64``) files are read as bytes, base64 encoded,
and then decoded as UTF-8.
- ``directory`` models
- The ``format`` field is always ``"json"``.
- The ``mimetype`` field is always ``None``.
- The ``content`` field contains a list of :ref:`content-free<contentfree>`
models representing the entities in the directory.
.. note::
.. _contentfree:
In certain circumstances, we don't need the full content of an entity to
complete a Contents API request. In such cases, we omit the ``mimetype``,
``content``, and ``format`` keys from the model. This most commonly occurs
when listing a directory, in which circumstance we represent files within
the directory as content-less models to avoid having to recursively traverse
and serialize the entire filesystem.
**Sample Models**
.. sourcecode:: python
# Notebook Model with Content
{
'content': {
'metadata': {},
'nbformat': 4,
'nbformat_minor': 0,
'cells': [
{
'cell_type': 'markdown',
'metadata': {},
'source': 'Some **Markdown**',
},
],
},
'created': datetime(2015, 7, 25, 19, 50, 19, 19865),
'format': 'json',
'last_modified': datetime(2015, 7, 25, 19, 50, 19, 19865),
'mimetype': None,
'name': 'a.ipynb',
'path': 'foo/a.ipynb',
'type': 'notebook',
'writable': True,
}
# Notebook Model without Content
{
'content': None,
'created': datetime.datetime(2015, 7, 25, 20, 17, 33, 271931),
'format': None,
'last_modified': datetime.datetime(2015, 7, 25, 20, 17, 33, 271931),
'mimetype': None,
'name': 'a.ipynb',
'path': 'foo/a.ipynb',
'type': 'notebook',
'writable': True
}
API Paths
~~~~~~~~~
.. _apipaths:
ContentsManager methods represent the locations of filesystem resources as
**API-style paths**. Such paths are interpreted as relative to the root
directory of the notebook server. For compatibility across systems, the
following guarantees are made:
* Paths are always ``unicode``, not ``bytes``.
* Paths are not URL-escaped.
* Paths are always forward-slash (/) delimited, even on Windows.
* Leading and trailing slashes are stripped. For example, ``/foo/bar/buzz/``
becomes ``foo/bar/buzz``.
* The empty string (``""``) represents the root directory.
Writing a Custom ContentsManager
--------------------------------
The default ContentsManager is designed for users running the notebook as an
application on a personal computer. It stores notebooks as .ipynb files on the
local filesystem, and it maps files and directories in the Notebook UI to files
and directories on disk. It is possible to override how notebooks are stored
by implementing your own custom subclass of ``ContentsManager``. For example,
if you deploy the notebook in a context where you don't trust or don't have
access to the filesystem of the notebook server, it's possible to write your
own ContentsManager that stores notebooks and files in a database.
Required Methods
~~~~~~~~~~~~~~~~
A minimal complete implementation of a custom
:class:`~manager.ContentsManager` must implement the following
methods:
.. autosummary::
ContentsManager.get
ContentsManager.save
ContentsManager.delete_file
ContentsManager.rename_file
ContentsManager.file_exists
ContentsManager.dir_exists
ContentsManager.is_hidden
Customizing Checkpoints
-----------------------
TODO:
Testing
-------
.. currentmodule:: notebook.services.contents.tests
:mod:`notebook.services.contents.tests` includes several test suites written
against the abstract Contents API. This means that an excellent way to test a
new ContentsManager subclass is to subclass our tests to make them use your
ContentsManager.
.. note::
PGContents_ is an example of a complete implementation of a custom
``ContentsManager``. It stores notebooks and files in PostgreSQL_ and encodes
directories as SQL relations. PGContents also provides an example of how to
re-use the notebook's tests.
.. _NBFormat: http://nbformat.readthedocs.org/en/latest/index.html
.. _PGContents: https://github.com/quantopian/pgcontents
.. _PostgreSQL: http://www.postgresql.org/
|
