1 # copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

     2 # contact http://www.logilab.fr/ -- mailto:contact@logilab.fr

     3 #

     4 # This file is part of CubicWeb.

     5 #

     6 # CubicWeb is free software: you can redistribute it and/or modify it under the

     7 # terms of the GNU Lesser General Public License as published by the Free

     8 # Software Foundation, either version 2.1 of the License, or (at your option)

     9 # any later version.

    10 #

    11 # CubicWeb is distributed in the hope that it will be useful, but WITHOUT

    12 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

    13 # FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more

    14 # details.

    15 #

    16 # You should have received a copy of the GNU Lesser General Public License along

    17 # with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

    18 """SPARQL integration"""

    19 

    20 __docformat__ = "restructuredtext en"

    21 from cubicweb import _

    22 

    23 from six.moves import range

    24 

    25 from yams import xy

    26 from rql import TypeResolverException

    27 

    28 from lxml import etree

    29 from lxml.builder import E

    30 

    31 from cubicweb.view import StartupView, AnyRsetView

    32 from cubicweb.web import Redirect, form, formfields, formwidgets as fwdgs

    33 from cubicweb.web.views import forms

    34 try:

    35     from cubicweb.spa2rql import Sparql2rqlTranslator, UnsupportedQuery

    36 except ImportError:

    37     # fyzz not available (only a recommends)

    38     Sparql2rqlTranslator = None

    39 

    40 class SparqlForm(forms.FieldsForm):

    41     __regid__ = 'sparql'

    42     sparql = formfields.StringField(help=_('type here a sparql query'))

    43     resultvid = formfields.StringField(choices=((_('table'), 'table'),

    44                                                 (_('sparql xml'), 'sparqlxml')),

    45                                        widget=fwdgs.Radio,

    46                                        value='table')

    47     form_buttons = [fwdgs.SubmitButton()]

    48     @property

    49     def action(self):

    50         return self._cw.url()

    51 

    52 

    53 class SparqlFormView(form.FormViewMixIn, StartupView):

    54     __regid__ = 'sparql'

    55     def call(self):

    56         form = self._cw.vreg['forms'].select('sparql', self._cw)

    57         form.render(w=self.w)

    58         sparql = self._cw.form.get('sparql')

    59         vid = self._cw.form.get('resultvid', 'table')

    60         if sparql:

    61             try:

    62                 qinfo = Sparql2rqlTranslator(self._cw.vreg.schema).translate(sparql)

    63             except TypeResolverException as exc:

    64                 self.w(self._cw._('can not resolve entity types:') + u' ' + unicode(exc))

    65             except UnsupportedQuery:

    66                 self.w(self._cw._('we are not yet ready to handle this query'))

    67             except xy.UnsupportedVocabulary as exc:

    68                 self.w(self._cw._('unknown vocabulary:') + u' ' + unicode(exc))

    69             else:

    70                 rql, args = qinfo.finalize()

    71                 if vid == 'sparqlxml':

    72                     url = self._cw.build_url('view', rql=rql % args, vid=vid)

    73                     raise Redirect(url)

    74                 rset = self._cw.execute(rql, args)

    75                 self.wview(vid, rset, 'null')

    76 

    77 

    78 ## sparql resultset views #####################################################

    79 

    80 YAMS_XMLSCHEMA_MAPPING = {

    81     'String': 'string',

    82 

    83     'Boolean': 'boolean',

    84     'Int': 'integer',

    85     'BigInt': 'integer',

    86     'Float': 'float',

    87 

    88     'Datetime': 'dateTime',

    89     'TZDatetime': 'dateTime',

    90     'Date': 'date',

    91     'Time': 'time',

    92     'TZTime': 'time',

    93 

    94     # XXX the following types don't have direct mapping

    95     'Decimal': 'string',

    96     'Interval': 'duration',

    97     'Bytes': 'base64Binary',

    98     'Password': 'string',

    99     }

   100 

   101 def xmlschema(yamstype):

   102     return 'http://www.w3.org/2001/XMLSchema#%s' % YAMS_XMLSCHEMA_MAPPING[yamstype]

   103 

   104 class SparqlResultXmlView(AnyRsetView):

   105     """The spec can be found here: http://www.w3.org/TR/rdf-sparql-XMLres/

   106     """

   107     __regid__ = 'sparqlxml'

   108     content_type = 'application/sparql-results+xml'

   109     templatable = False

   110 

   111     def call(self):

   112         # XXX handle UNION

   113         rqlst = self.cw_rset.syntax_tree().children[0]

   114         varnames = [var.name for var in rqlst.selection]

   115         results = E.results()

   116         for rowidx in range(len(self.cw_rset)):

   117             result = E.result()

   118             for colidx, varname in enumerate(varnames):

   119                 result.append(self.cell_binding(rowidx, colidx, varname))

   120             results.append(result)

   121         sparql = E.sparql(E.head(*(E.variable(name=name) for name in varnames)),

   122                           results)

   123         self.w(u'<?xml version="1.0"?>\n')

   124         self.w(etree.tostring(sparql, encoding=unicode, pretty_print=True))

   125 

   126     def cell_binding(self, row, col, varname):

   127         celltype = self.cw_rset.description[row][col]

   128         if self._cw.vreg.schema.eschema(celltype).final:

   129             cellcontent = self._cw.view('cell', self.cw_rset, row=row, col=col)

   130             return E.binding(E.literal(cellcontent,

   131                                        datatype=xmlschema(celltype)),

   132                              name=varname)

   133         else:

   134             entity = self.cw_rset.get_entity(row, col)

   135             return E.binding(E.uri(entity.absolute_url()), name=varname)

   136 

   137     def set_request_content_type(self):

   138         """overriden to set the correct filetype and filename"""

   139         self._cw.set_content_type(self.content_type,

   140                                   filename='sparql.xml',

   141                                   encoding=self._cw.encoding)

   142 

   143 def registration_callback(vreg):

   144     if Sparql2rqlTranslator is not None:

   145         vreg.register_all(globals().values(), __name__)