web/views/json.py
author Julien Cristau <julien.cristau@logilab.fr>
Tue, 16 Sep 2014 18:01:51 +0200
changeset 9948 798ab1216523
parent 9492 c7fc56eecd1a
child 10013 b68088082280
permissions -rw-r--r--
[test] Make test_undo_api less random The order in which hooks are run is not predictable if they have the same 'order' attribute, which is the case for SetOwnershipHook and SetInitialStateHook. So don't assume in_state will be set before created_by.

# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
"""json export views"""

__docformat__ = "restructuredtext en"
_ = unicode

from cubicweb.utils import json_dumps
from cubicweb.predicates import any_rset
from cubicweb.view import EntityView, AnyRsetView
from cubicweb.web.application import anonymized_request
from cubicweb.web.views import basecontrollers

class JsonpController(basecontrollers.ViewController):
    """The jsonp controller is the same as a ViewController but :

    - anonymize request (avoid CSRF attacks)
    - if ``vid`` parameter is passed, make sure it's sensible (i.e. either
      "jsonexport" or "ejsonexport")
    - if ``callback`` request parameter is passed, it's used as json padding


    Response's content-type will either be ``application/javascript`` or
    ``application/json`` depending on ``callback`` parameter presence or not.
    """
    __regid__ = 'jsonp'

    def publish(self, rset=None):
        if 'vid' in self._cw.form:
            vid = self._cw.form['vid']
            if vid not in ('jsonexport', 'ejsonexport'):
                self.warning("vid %s can't be used with jsonp controller, "
                             "falling back to jsonexport", vid)
                self._cw.form['vid'] = 'jsonexport'
        else: # if no vid is specified, use jsonexport
            self._cw.form['vid'] = 'jsonexport'
        if self._cw.vreg.config['anonymize-jsonp-queries']:
            with anonymized_request(self._cw):
                return self._get_json_data(rset)
        else:
            return self._get_json_data(rset)

    def _get_json_data(self, rset):
        json_data = super(JsonpController, self).publish(rset)
        if 'callback' in self._cw.form: # jsonp
            json_padding = self._cw.form['callback']
            # use ``application/javascript`` is ``callback`` parameter is
            # provided, let ``application/json`` otherwise
            self._cw.set_content_type('application/javascript')
            json_data = '%s(%s)' % (json_padding, json_data)
        return json_data


class JsonMixIn(object):
    """mixin class for json views

    Handles the following optional request parameters:

    - ``_indent`` : must be an integer. If found, it is used to pretty print
      json output
    """
    templatable = False
    content_type = 'application/json'
    binary = True

    def wdata(self, data):
        if '_indent' in self._cw.form:
            indent = int(self._cw.form['_indent'])
        else:
            indent = None
        self.w(json_dumps(data, indent=indent))


class JsonRsetView(JsonMixIn, AnyRsetView):
    """dumps raw result set in JSON format"""
    __regid__ = 'jsonexport'
    __select__ = any_rset() # means rset might be empty or have any shape
    title = _('json-export-view')

    def call(self):
        # XXX mimic w3c recommandations to serialize SPARQL results in json?
        #     http://www.w3.org/TR/rdf-sparql-json-res/
        self.wdata(self.cw_rset.rows)


class JsonEntityView(JsonMixIn, EntityView):
    """dumps rset entities in JSON

    The following additional metadata is added to each row :

    - ``__cwetype__`` : entity type
    """
    __regid__ = 'ejsonexport'
    title = _('json-entities-export-view')

    def call(self):
        entities = []
        for entity in self.cw_rset.entities():
            entity.complete() # fetch all attributes
            # hack to add extra metadata
            entity.cw_attr_cache.update({
                    '__cwetype__': entity.cw_etype,
                    })
            entities.append(entity)
        self.wdata(entities)