1 files changed, 141 insertions, 0 deletions
diff --git a/creactivistore/_templates/lib/triplestore/datastore.py b/creactivistore/_templates/lib/triplestore/datastore.py
new file mode 100644
index 0000000..f83b21b
--- /dev/null
+++ b/creactivistore/_templates/lib/triplestore/datastore.py
@@ -0,0 +1,141 @@
+'''
+Created on Feb 19, 2011
+
+@author: cgueret
+'''
+from rdflib import ConjunctiveGraph, RDF, URIRef, Namespace, Literal
+import httplib
+import urllib
+import uuid
+
+OLPC = Namespace("http://example.org/")
+
+class DatastoreItem(object):
+    def __init__(self, type, id=None):
+        self.id = uuid.uuid1() if id is None else id
+        self.meta = {}
+        self.meta[RDF.type] = URIRef(OLPC[type])
+
+    def append_metadata(self, key, value):
+        '''
+        Append a new value for a given key
+        '''
+        # Set the namespace to the key
+        if type(key) == type(''):
+            key = OLPC[key]
+        # If not in, create
+        if key not in self.meta.keys():
+            self.meta[key] = []
+        else:
+            # Convert the key to an array if it was a singleton
+            if (type(self.meta[key]) != type([])):
+                tmp = self.meta[key]
+                self.meta[key] = [tmp]
+        # Append the value
+        self.meta[key].append(value)
+
+    def delete_metadata(self, key, value=None):
+        '''
+        Suppress a key or a value within a specific key
+        '''
+        # Set the namespace to the key
+        if type(key) == type(''):
+            key = OLPC[key]
+        if key not in self.meta.keys():
+            return
+        if value == None:
+            del self.meta[key]
+        else:
+            if (type(self.meta[key]) == type([])):
+                self.meta[key].remove(value)
+                if len(self.meta[key]) == 0:
+                    del self.meta[key]
+
+    def set_metadata(self, key, value):
+        '''
+        Assign a specific value to a meta data key
+        '''
+        # If the key is a string, force the default namespace
+        if type(key) == type(''):
+            key = OLPC[key]
+        self.meta[key] = [value]
+
+    def get_metadata(self, key = None):
+        if key == None:
+            return self.meta.items()
+        else:
+            if type(key) == type(''):
+                key = OLPC[key]
+            if key not in self.meta.keys():
+                return []
+            return self.meta[key]
+
+    def get_resource(self):
+        return URIRef(OLPC['resource/%s' % self.id])
+
+class Datastore(object):
+    def __init__(self, url):
+        self.url = url
+
+    def sparql_get(self, query):
+        params = {'query': query, 'format' : 'csv'}
+        headers = {'Content-Type': 'application/x-www-form-urlencoded'}
+        conn = httplib.HTTPConnection(self.url)
+        conn.request("POST", "/sparql",
+                     urllib.urlencode(params), headers=headers)
+        response = conn.getresponse()
+        results = response.read().split('\n')[1:-1]
+        conn.close()
+        return results
+
+    def get_items(self, type):
+        '''
+        Query the datastore for all the items
+        '''
+        query = 'SELECT * WHERE { ?s <%s> <%s>} ORDER BY ?s'\
+                % (RDF.type, OLPC[type])
+        items = []
+        for line in self.sparql_get(query):
+            uri = line.split(',')[-1][4:-1]
+            id = uri.split('/')[-1]
+            print "load item %s" % id
+            item = DatastoreItem(type, id)
+            items.append(item)
+            # Load all the meta data
+            query = 'SELECT * WHERE { <%s> ?p ?o}' % item.get_resource()
+            for line in self.sparql_get(query):
+                (p,o) = line.split(',')[1:]
+                if p[4:-1] == 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type':
+                    continue
+                p = URIRef(p[4:-1])
+                if o[0:3] == 'uri':
+                    o = URIRef(o[4:-1])
+                elif o[0] == '"':
+                    o = Literal(o[1:-1])
+                item.set_metadata(p, o)
+        return items
+
+    def save_item(self, item):
+        '''
+        Convert the item into a graph and put the graph into the triple store
+        '''
+        # Delete the previous triples associated to that resource
+        # conn = httplib.HTTPConnection(self.url)
+        # conn.request("DELETE", "/data/%s" % item.get_resource())
+        # conn.close()
+        # Generate the new graph
+        graph = ConjunctiveGraph()
+        for (key, values) in item.get_metadata():
+            if type(values) == type([]):
+                for value in values:
+                    graph.add((item.get_resource(), key, value))
+            else:
+                graph.add((item.get_resource(), key, values))
+        # Save it
+        #print graph.serialize()
+        headers = { 'Accept' : '*/*', 'Content-Type': 'application/rdf+xml' }
+        conn = httplib.HTTPConnection(self.url)
+        conn.request("PUT", "/data/%s" % item.get_resource(),
+                     body=graph.serialize(), headers=headers)
+        conn.getresponse()
+        conn.close()