mirror of https://github.com/mitsuhiko/flask.git
Armin Ronacher
12 years ago
9 changed files with 224 additions and 81 deletions
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# -*- coding: utf-8 -*- |
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""" |
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flask.jsonimpl |
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~~~~~~~~~~~~~~ |
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Implementation helpers for the JSON support in Flask. |
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:copyright: (c) 2012 by Armin Ronacher. |
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:license: BSD, see LICENSE for more details. |
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""" |
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from datetime import datetime |
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from .globals import current_app, request |
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from werkzeug.http import http_date |
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# Use the same json implementation as itsdangerous on which we |
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# depend anyways. |
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from itsdangerous import simplejson as _json |
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# figure out if simplejson escapes slashes. This behavior was changed |
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# from one version to another without reason. |
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_slash_escape = '\\/' not in _json.dumps('/') |
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__all__ = ['dump', 'dumps', 'load', 'loads', 'htmlsafe_dump', |
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'htmlsafe_dumps', 'JSONDecoder', 'JSONEncoder', |
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'jsonify'] |
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class JSONEncoder(_json.JSONEncoder): |
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"""The default Flask JSON encoder. This one extends the default simplejson |
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encoder by also supporting ``datetime`` objects as well as ``Markup`` |
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objects which are serialized as RFC 822 datetime strings (same as the HTTP |
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date format). In order to support more data types override the |
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:meth:`default` method. |
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""" |
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def default(self, o): |
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"""Implement this method in a subclass such that it returns a |
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serializable object for ``o``, or calls the base implementation (to |
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raise a ``TypeError``). |
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For example, to support arbitrary iterators, you could implement |
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default like this:: |
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def default(self, o): |
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try: |
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iterable = iter(o) |
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except TypeError: |
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pass |
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else: |
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return list(iterable) |
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return JSONEncoder.default(self, o) |
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""" |
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if isinstance(o, datetime): |
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return http_date(o) |
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if hasattr(o, '__html__'): |
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return unicode(o.__html__()) |
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return _json.JSONEncoder.default(self, o) |
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class JSONDecoder(_json.JSONDecoder): |
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"""The default JSON decoder. This one does not change the behavior from |
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the default simplejson encoder. Consult the :mod:`json` documentation |
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for more information. This decoder is not only used for the load |
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functions of this module but also :attr:`~flask.Request`. |
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""" |
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def dumps(obj, **kwargs): |
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"""Serialize ``obj`` to a JSON formatted ``str`` by using the application's |
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configured encoder (:attr:`~flask.Flask.json_encoder`). |
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""" |
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kwargs.setdefault('cls', current_app.json_encoder) |
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return _json.dumps(obj, **kwargs) |
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def dump(obj, fp, **kwargs): |
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"""Like :func:`dumps` but writes into a file object.""" |
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kwargs.setdefault('cls', current_app.json_encoder) |
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return _json.dump(obj, fp, **kwargs) |
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def loads(s, **kwargs): |
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"""Unserialize a JSON object from a string ``s`` by using the application's |
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configured decoder (:attr:`~flask.Flask.json_decoder`). |
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""" |
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kwargs.setdefault('cls', current_app.json_decoder) |
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return _json.loads(s, **kwargs) |
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def load(fp, **kwargs): |
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"""Like :func:`loads` but reads from a file object. |
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""" |
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kwargs.setdefault('cls', current_app.json_decoder) |
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return _json.load(fp, **kwargs) |
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def htmlsafe_dumps(obj, **kwargs): |
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"""Works exactly like :func:`dumps` but is safe for use in ``<script>`` |
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tags. It accepts the same arguments and returns a JSON string. Note that |
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this is available in templates through the ``|tojson`` filter but it will |
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have to be wrapped in ``|safe`` unless **true** XHTML is being used. |
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""" |
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rv = dumps(obj, **kwargs) |
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if _slash_escape: |
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rv = rv.replace('/', '\\/') |
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return rv.replace('<!', '<\\u0021') |
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def htmlsafe_dump(obj, fp, **kwargs): |
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"""Like :func:`htmlsafe_dumps` but writes into a file object.""" |
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fp.write(htmlsafe_dumps(obj, **kwargs)) |
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def jsonify(*args, **kwargs): |
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"""Creates a :class:`~flask.Response` with the JSON representation of |
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the given arguments with an `application/json` mimetype. The arguments |
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to this function are the same as to the :class:`dict` constructor. |
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Example usage:: |
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@app.route('/_get_current_user') |
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def get_current_user(): |
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return jsonify(username=g.user.username, |
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email=g.user.email, |
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id=g.user.id) |
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This will send a JSON response like this to the browser:: |
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{ |
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"username": "admin", |
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"email": "admin@localhost", |
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"id": 42 |
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} |
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This requires Python 2.6 or an installed version of simplejson. For |
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security reasons only objects are supported toplevel. For more |
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information about this, have a look at :ref:`json-security`. |
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.. versionadded:: 0.2 |
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""" |
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return current_app.response_class(dumps(dict(*args, **kwargs), |
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indent=None if request.is_xhr else 2), |
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mimetype='application/json') |
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