Merge pull request #252 from timrichardson/issue/1692v3

Issue/1692v3 OK merged my fix for virtual fields when fields argument is specified

gluon/sqlhtml.py

@@ -1913,6 +1913,11 @@ class SQLFORM(FORM):
                 tablenames += db._adapter.tables(join)
         tables = [db[tablename] for tablename in tablenames]
         if fields:
+            #add missing tablename to virtual fields
+            for table in tables:
+                for k,f in table.iteritems():
+                    if isinstance(f,Field.Virtual):
+                        f.tablename = table._tablename
             columns = [f for f in fields if f.tablename in tablenames]
         else:
             fields = []
@@ -1926,9 +1931,8 @@ class SQLFORM(FORM):
                     if not k.startswith('_'):
                         if isinstance(f,Field.Virtual) and f.readable:
                             f.tablename = table._tablename
-                            columns.append(f)
                             fields.append(f)
-                        
+                            columns.append(f)
         if not field_id:
             if groupby is None:
                 field_id = tables[0]._id
@@ -2271,11 +2275,9 @@ class SQLFORM(FORM):
             limitby = (paginate*page,paginate*(page+1))
         else:
             limitby = None
-
         try:
-            table_fields = filter(
-                lambda f: (f.tablename in tablenames) and \
-                    (not(isinstance(f,Field.Virtual))),fields)
+            table_fields = [field for field in fields
+                            if (field.tablename in tablenames and not(isinstance(field,Field.Virtual)))]
             if dbset._db._adapter.dbengine=='google:datastore':
                 rows = dbset.select(left=left,orderby=orderby,
                                     groupby=groupby,limitby=limitby,