Add source column inheritance and exclusions

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

HISTORY.rst

@@ -6,6 +6,8 @@
 - Use Select2 widget for the document type selection form.
 - Backport the vertical main menu update.
 - Backport workflow preview refactor. GitLab issue #532.
+- Add support for source column inheritance.
+- Add support for source column exclusion.
 
 3.2.5 (2019-07-05)
 ==================

docs/releases/3.3.rst

@@ -18,6 +18,8 @@ Changes
   a browser refresh will also restore its state to match the selected
   view.
 - Backport workflow preview refactor. GitLab issue #532.
+- Add support for source column inheritance.
+- Add support for source column exclusion.
 
 Removals
 --------

mayan/apps/navigation/classes.py

@@ -577,44 +577,63 @@ class SourceColumn(object):
 
     @classmethod
     def get_for_source(cls, context, source, exclude_identifier=False, only_identifier=False):
+        columns = []
+
+        source_classes = set()
+
+        if hasattr(source, '_meta'):
+            source_classes.add(source._meta.model)
+        else:
+            source_classes.add(source)
+
         try:
-            result = cls._registry[source]
+            columns.extend(cls._registry[source])
+        except KeyError:
+            pass
+
+        try:
+            # Might be an instance, try its class
+            columns.extend(cls._registry[source.__class__])
         except KeyError:
             try:
-                # Might be an instance, try its class
-                result = cls._registry[source.__class__]
+                # Might be a subclass, try its root class
+                columns.extend(cls._registry[source.__class__.__mro__[-2]])
             except KeyError:
-                try:
-                    # Might be a subclass, try its root class
-                    result = cls._registry[source.__class__.__mro__[-2]]
-                except KeyError:
-                    try:
-                        # Might be an inherited class insance, try its source class
-                        result = cls._registry[source.source_ptr.__class__]
-                    except (KeyError, AttributeError):
-                        try:
-                            # Try it as a queryset
-                            result = cls._registry[source.model]
-                        except AttributeError:
-                            try:
-                                # Special case for queryset items produced from
-                                # .defer() or .only() optimizations
-                                result = cls._registry[list(source._meta.parents.items())[0][0]]
-                            except (AttributeError, KeyError, IndexError):
-                                result = ()
-        except TypeError:
-            # unhashable type: list
-            result = ()
+                pass
 
-        result = SourceColumn.sort(columns=result)
+        try:
+            # Might be an inherited class instance, try its source class
+            columns.extend(cls._registry[source.source_ptr.__class__])
+        except (KeyError, AttributeError):
+            pass
+
+        try:
+            # Try it as a queryset
+            columns.extend(cls._registry[source.model])
+        except AttributeError:
+            try:
+                # Special case for queryset items produced from
+                # .defer() or .only() optimizations
+                result = cls._registry[list(source._meta.parents.items())[0][0]]
+            except (AttributeError, KeyError, IndexError):
+                pass
+            else:
+                # Second level special case for model subclasses from
+                # .defer and .only querysets
+                # Examples: Workflow runtime proxy and index instances in 3.2.x
+                for column in result:
+                    if not source_classes.intersection(set(column.exclude)):
+                        columns.append(column)
+
+        columns = SourceColumn.sort(columns=columns)
 
         if exclude_identifier:
-            result = [item for item in result if not item.is_identifier]
+            columns = [column for column in columns if not column.is_identifier]
         else:
             if only_identifier:
-                for item in result:
-                    if item.is_identifier:
-                        return item
+                for column in columns:
+                    if column.is_identifier:
+                        return column
                 return None
 
         final_result = []
@@ -635,12 +654,12 @@ class SourceColumn(object):
                 return result
 
         current_view_name = get_current_view_name(request=request)
-        for item in result:
-            if item.views:
-                if current_view_name in item.views:
-                    final_result.append(item)
+        for column in columns:
+            if column.views:
+                if current_view_name in column.views:
+                    final_result.append(column)
             else:
-                final_result.append(item)
+                final_result.append(column)
 
         return final_result
 
@@ -655,6 +674,7 @@ class SourceColumn(object):
         self._label = label
         self.attribute = attribute
         self.empty_value = empty_value
+        self.exclude = ()
         self.func = func
         self.is_attribute_absolute_url = is_attribute_absolute_url
         self.is_object_absolute_url = is_object_absolute_url
@@ -697,6 +717,9 @@ class SourceColumn(object):
 
         self.label = self._label
 
+    def add_exclude(self, source):
+        self.exclude = self.exclude + (source,)
+
     def get_absolute_url(self, obj):
         if self.is_object_absolute_url:
             return obj.get_absolute_url()