[GRAPH EXPLORER] Better types to check parameters and give user some usefull...

[GRAPH EXPLORER] Better types to check parameters and give user some usefull informations. I extensively use the Either type of Haskell that is needed to easyly understand the logic of the process.

graph/graph.py

@@ -27,6 +27,15 @@ def get_graph( request=None         , corpus=None
         ):
     '''
     Get_graph : main steps:
+    0) Check the parameters
+    
+    get_graph :: GraphParameters -> Either (Dic Nodes Links) (Dic State Length)
+        where type Length = Int
+
+    get_graph first checks the parameters and return either graph data or a dic with 
+    state "type" with an integer to indicate the size of the parameter 
+    (maybe we could add a String in that step to factor and give here the error message)
+
     1) count Cooccurrences  (function countCooccurrences)
             main parameters: threshold
 
@@ -54,11 +63,11 @@ def get_graph( request=None         , corpus=None
         if mapList_id is None:
             mapList_id = session.query(Node.id).filter(Node.typename == "MAPLIST").first()[0]
 
-        mapList_size = session.query(NodeNgram).filter(NodeNgram.node_id == mapList_id)
-        
-        if mapList_size.count() < graph_constraints['mapList']:
+        mapList_size_query = session.query(NodeNgram).filter(NodeNgram.node_id == mapList_id)
+        mapList_size = mapList_size_query.count()
+        if mapList_size < graph_constraints['mapList']:
             # Do not compute the graph if mapList is not big enough
-            return {'nodes':[mapList_size.count()], 'links':[0,0,0]}
+            return {'state': "mapListError", "length" : mapList_size}
 
 
         # case of corpus not big enough
@@ -103,7 +112,8 @@ def get_graph( request=None         , corpus=None
 
         # Finally test if the size of the corpora is big enough
         # --------------------------------
-        if corpus_size_query.count() > graph_constraints['corpusMax']:
+        corpus_size = corpus_size_query.count()
+        if corpus_size > graph_constraints['corpusMax']:
             # Then compute cooc asynchronously with celery
             scheduled(countCooccurrences)( corpus_id=corpus.id
                                        #, field1="ngrams", field2="ngrams"
@@ -113,13 +123,13 @@ def get_graph( request=None         , corpus=None
                                         , save_on_db = True
                                        #, limit=size
                                         )
-            # Dic hack to inform user that graph is computed asynchronously
-            # (Impossible graph: no nodes with one link)
-            return {'nodes':[], 'links':[0]}  
+            # Dic to inform user that corpus maximum is reached then
+            # graph is computed asynchronously
+            return {"state" : "corpusMax", "length" : corpus_size}
         
-        elif corpus_size_query.count() <= graph_constraints['corpusMin']:
+        elif corpus_size <= graph_constraints['corpusMin']:
             # Do not compute the graph if corpus is not big enough
-            return {'nodes':[corpus_size_query.count()], 'links':[0,0]}  
+            return {"state" : "corpusMin", "length" : corpus_size}
   
         else:
             # If graph_constraints are ok then compute the graph in live

graph/rest.py

@@ -142,10 +142,12 @@ class Graph(APIView):
                                    )
 
 
-                # Test data length
-                # A graph needs more than 3 nodes and 3 links
-                # Others graphs are used to check the errors
-                if len(data['nodes']) > 3 and len(data['links']) > 3 :
+                # data :: Either (Dic Nodes Links) (Dic State Length)
+                
+                # data_test :: Either String Bool
+                data_test = data.get("state", True)
+
+                if data_test is True:
                     # normal case --------------------------------
                     if format_ == 'json':
                         return JsonHttpResponse(
@@ -154,7 +156,9 @@ class Graph(APIView):
                                )
                     # --------------------------------------------
                 
-                elif len(data['nodes']) == 1 and len(data['links']) == 2 :
+                else:
+                    # All other cases (more probable are higher in the if list)
+                    if data["state"] == "corpusMin":
                         # async data case
                         return JsonHttpResponse({
                             'msg': '''Problem: your corpus is too small (only %d documents).
@@ -164,14 +168,14 @@ class Graph(APIView):
 
                                       You can manage your corpus here:
                                       http://%sgargantext.org/projects/%d/
-                                  ''' % ( data['nodes'][0]
+                                      ''' % ( data["length"]
                                             , graph_constraints['corpusMin']
                                             , "dev."
                                             , corpus.parent_id
                                             ),
                             }, status=400)
                 
-                elif len(data['nodes']) == 1 and len(data['links']) == 3 :
+                    elif data["state"] == "mapListError":
                         # async data case
                         return JsonHttpResponse({
                             'msg': '''Problem: your map list is too small (currently %d terms).
@@ -181,7 +185,7 @@ class Graph(APIView):
 
                                       You can manage your map terms here:
                                       http://%sgargantext.org/projects/%d/corpora/%d/terms
-                                  ''' % ( data['nodes'][0]
+                                      ''' % ( data["length"]
                                             , graph_constraints['mapList']
                                             , "dev."
                                             , corpus.parent_id
@@ -190,21 +194,27 @@ class Graph(APIView):
                             }, status=400)
 
 
-                elif len(data['nodes']) == 0 and len(data['links']) == 0 :
+                    elif data["state"] == "corpusMax":
                         # async data case
                         return JsonHttpResponse({
-                        'msg': '''Warning: Async graph generation.
+                            'msg': '''Warning: Async graph generation since your corpus is
+                                      big (about %d documents).
 
                                       Wait a while and discover your graph very soon.
 
-                                  Click on the link and see your current graph 
+                                      Click on the link below and see your current graph 
                                       processing on top of the list:
                                       
-                                  http://%sgargantext.org/projects/%d/corpora/%d/myGraph
-                                  ''' % ("dev.", corpus.parent_id, corpus.id),
+                                      http://%sgargantext.org/projects/%d/corpora/%d/myGraphs
+                                      ''' % (data["length"], "dev.", corpus.parent_id, corpus.id),
+                            }, status=400)
+                    else :
+                       return JsonHttpResponse({
+                            'msg': '''Programming error.''',
                             }, status=400)
 
-                else:
+
+            elif len(data["nodes"]) < 2 and len(data["links"]) < 2:
                 # empty data case
                 return JsonHttpResponse({
                     'msg': '''Empty graph warning