[FEATURE] Added a RESTful URL :...

[FEATURE] Added a RESTful URL : /api/corpus/95/data?mesured=ngrams.count&parameters[]=metadata.publication_year&filters[]=ngram.terms|bees

gargantext_web/api.py

@@ -3,7 +3,7 @@ from django.core.exceptions import PermissionDenied, SuspiciousOperation
 from django.core.exceptions import ValidationError
 
 from django.db.models import Avg, Max, Min, Count
-from node.models import NodeType, Node, Ngram
+from node.models import NodeType, Node, Node_Ngram, Ngram
 
 from django.db import connection
 
@@ -82,3 +82,80 @@ def corpus_metadata(request, corpus_id):
     return JsonHttpResponse({
         "list" : [row[0] for row in cursor.fetchall()],
     })
+    
+
+# ?mesured=documents.count
+# &parameters[]=metadata.publication_year
+# &filter[]=ngrams.in.test,ht,grf
+
+def corpus_data(request, corpus_id):
+    # parameters retrieval and control
+    corpusQuery = Node.objects.filter(id = corpus_id)
+    if not corpusQuery:
+        raise Http404("No such corpus.")
+    corpus = corpusQuery.first()
+    if corpus.type.name != 'Corpus':
+        raise Http404("No such corpus.")
+    # query building: initialization
+    columns     = []
+    conditions  = []
+    group       = []
+    order       = []
+    join_ngrams = False
+    # query building: parameters
+    for parameter in request.GET.getlist('parameters[]'):
+        c = len(columns)
+        parameter_array = parameter.split('.')
+        if len(parameter_array) != 2:
+            raise ValidationError('Unrecognized "parameter[]=%s"' % (parameter, ))
+        origin = parameter_array[0]
+        key = parameter_array[1]
+        if origin == "metadata":
+            key = key.replace('\'', '\\\'')
+            columns.append("node.metadata->'%s' AS c%d" % (key, c, ))
+            conditions.append("node.metadata ? '%s'" % (key, ))
+            group.append("c%d" % (c, ))
+            order.append("c%d" % (c, ))
+        else:
+            raise ValidationError('Unrecognized type "%s" in "parameter[]=%s"' % (origin, parameter, ))
+    # query building: mesured value
+    mesured = request.GET.get('mesured', '')
+    c = len(columns)
+    if mesured == "documents.count":
+        columns.append("COUNT(node.id) AS c%d " % (c, ))
+    elif mesured == "ngrams.count":
+        columns.append("COUNT(ngram.id) AS c%d " % (c, ))
+        join_ngrams = True
+    else:
+        raise ValidationError('The "mesured" parameter should take one of the following values: "documents.count", "ngrams.count"')
+    # query building: filters
+    for filter in request.GET.getlist('filters[]', ''):
+        if '|' in filter:
+            filter_array = filter.split("|")
+            key = filter_array[0]
+            values = filter_array[1].replace("'", "\\'").split(",")
+            if key == 'ngram.terms':
+                conditions.append("ngram.terms IN ('%s')" % ("', '".join(values), ))
+                join_ngrams = True
+        else:
+            raise ValidationError('Unrecognized "filter[]=%s"' % (filter, ))
+    # query building: assembling
+    sql = "SELECT %s FROM %s AS node" % (', '.join(columns), Node._meta.db_table, )
+    if join_ngrams:
+        sql += " INNER JOIN %s AS node_ngram ON node_ngram.node_id = node.id" % (Node_Ngram._meta.db_table, )
+        sql += " INNER JOIN %s AS ngram ON ngram.id = node_ngram.ngram_id" % (Ngram._meta.db_table, )
+    if conditions:
+        sql += " WHERE %s" % (" AND ".join(conditions), )
+    if group:
+        sql += " GROUP BY %s" % (", ".join(group), )
+    if order:
+        sql += " ORDER BY %s" % (", ".join(order), )
+    # query execution
+    # return HttpResponse(sql)
+    cursor = connection.cursor()
+    cursor.execute(sql)
+    # response building
+    return JsonHttpResponse({
+        "list": [row for row in cursor.fetchall()],
+    })
+

gargantext_web/urls.py

@@ -42,6 +42,7 @@ urlpatterns = patterns('',
 
     url(r'^api/corpus/(\d+)/ngrams$', gargantext_web.api.corpus_ngrams),
     url(r'^api/corpus/(\d+)/metadata$', gargantext_web.api.corpus_metadata),
+    url(r'^api/corpus/(\d+)/data$', gargantext_web.api.corpus_data),
 )
 
 from django.conf import settings