1 # -*- coding: utf-8 -*-

     2 '''

     3 Created on Jun 11, 2013

     4 

     5 @author: ymh

     6 '''

     7 

     8 from rdflib import plugin, ConjunctiveGraph, URIRef, Literal

     9 from rdflib.store import Store

    10 from django.db import connections

    11 

    12 class TermGraph(ConjunctiveGraph):

    13     

    14     def __init__(self, do_open=False, create=False):

    15         identifier = "jocondelab"        

    16         store = plugin.get("SQLAlchemy", Store)(identifier=identifier)

    17         ConjunctiveGraph.__init__(self, store=store, identifier=identifier)

    18         if do_open:

    19             self.open(create)

    20 

    21     def open(self, create=False):

    22         db_settings = connections['default'].settings_dict

    23         sa_db_settings = {

    24             'engine': 'postgresql+psycopg2' if db_settings['ENGINE'] == "django.db.backends.postgresql_psycopg2" else db_settings['ENGINE'],

    25             'user': db_settings['USER'],

    26             'password': db_settings['PASSWORD'],

    27             'port': db_settings['PORT'] if db_settings['PORT'] else "5432",

    28             'host': db_settings['HOST'] if db_settings['HOST'] else "localhost",

    29             'name': db_settings['NAME']             

    30         } 

    31         connect_config = "%(engine)s://%(user)s:%(password)s@%(host)s:%(port)s/%(name)s"%sa_db_settings 

    32 

    33         return ConjunctiveGraph.open(self, connect_config, create=create)

    34 

    35     def get_uri_for_term(self, term, context):

    36         c = URIRef(context)

    37         tl = Literal(term)

    38         

    39         for s,p,_ in self.triples((None, None, tl), context=c):

    40             if p in [URIRef("http://www.w3.org/2004/02/skos/core#prefLabel"), URIRef("http://www.w3.org/2004/02/skos/core#alternateLabel")]:

    41                 return unicode(s)

    42         return None

    43 

    44 graph = TermGraph(do_open=True, create=False)