Improve the resolve_attribute function

Update the arguments of the function to be full length and more explicit.
Use exceptions to find the correct way of using the attribute of the
object passed instead of trying to use introspection.
Add support for passing key word arguments to the attribute being
resolved even if it is a class method.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/acls/managers.py

@@ -46,7 +46,7 @@ class AccessControlListManager(models.Manager):
                 stored_permissions = (permissions.stored_permission,)
 
             if related:
-                obj = resolve_attribute(obj, related)
+                obj = resolve_attribute(obj=obj, attribute=related)
 
             try:
                 parent_accessor = ModelPermission.get_inheritance(
@@ -200,7 +200,7 @@ class AccessControlListManager(models.Manager):
         else:
             try:
                 parent_object = resolve_attribute(
-                    obj=instance, attrib=parent_accessor
+                    obj=instance, attribute=parent_accessor
                 )
             except AttributeError:
                 # Parent accessor is not an attribute, try it as a related

mayan/apps/common/forms.py

@@ -43,7 +43,7 @@ class DetailForm(forms.ModelForm):
         super(DetailForm, self).__init__(*args, **kwargs)
 
         for extra_field in self.extra_fields:
-            result = resolve_attribute(self.instance, extra_field['field'])
+            result = resolve_attribute(obj=self.instance, attribute=extra_field['field'])
             label = 'label' in extra_field and extra_field['label'] or None
             # TODO: Add others result types <=> Field types
             if isinstance(result, models.query.QuerySet):
@@ -54,8 +54,8 @@ class DetailForm(forms.ModelForm):
                 self.fields[extra_field['field']] = forms.CharField(
                     label=extra_field['label'],
                     initial=resolve_attribute(
-                        self.instance,
-                        extra_field['field'], None
+                        obj=self.instance,
+                        attribute=extra_field['field']
                     ),
                     widget=extra_field.get('widget', PlainWidget)
                 )

mayan/apps/common/templatetags/common_tags.py

@@ -32,8 +32,8 @@ def get_collections():
 @register.filter
 def get_encoded_parameter(item, parameters_dict):
     result = {}
-    for attrib_name, attrib in parameters_dict.items():
-        result[attrib_name] = resolve_attribute(item, attrib)
+    for key, value in parameters_dict.items():
+        result[key] = resolve_attribute(obj=item, attribute=value)
     return dumps(result)
 
 
@@ -44,7 +44,7 @@ def get_type(value):
 
 @register.filter
 def object_property(value, arg):
-    return resolve_attribute(value, arg)
+    return resolve_attribute(obj=value, attribute=arg)
 
 
 @register.simple_tag

mayan/apps/common/utils.py

@@ -130,29 +130,37 @@ def resolve(path, urlconf=None):
     return django_resolve(path=path, urlconf=urlconf)
 
 
-def resolve_attribute(obj, attrib, arguments=None):
-    if isinstance(attrib, types.FunctionType):
-        return attrib(obj)
-    elif isinstance(obj, dict_type) or isinstance(obj, dictionary_type):
-        return obj[attrib]
-    else:
+def resolve_attribute(obj, attribute, kwargs=None):
+    if not kwargs:
+        kwargs = {}
+
+    # Try as a callable
+    try:
+        return attribute(obj, **kwargs)
+    except TypeError:
+        # Try as a dictionary
         try:
-            result = reduce_function(getattr, attrib.split('.'), obj)
-            if isinstance(result, types.MethodType):
-                if arguments:
-                    return result(**arguments)
+            return obj[attribute]
+        except TypeError:
+            try:
+                # If there are dots in the attribute name, traverse them
+                # to the final attribute
+                result = reduce_function(getattr, attribute.split('.'), obj)
+                try:
+                    # Try it as a method
+                    return result(**kwargs)
+                except TypeError:
+                    # Try it as a property
+                    return result
+            except AttributeError:
+                # Try as a related model field
+                if LOOKUP_SEP in attribute:
+                    attrib = attribute.replace(LOOKUP_SEP, '.')
+                    return resolve_attribute(
+                        obj=obj, attribute=attribute, kwargs=kwargs
+                    )
                 else:
-                    return result()
-            else:
-                return result
-        except AttributeError:
-            if LOOKUP_SEP in attrib:
-                attrib = attrib.replace(LOOKUP_SEP, '.')
-                return resolve_attribute(
-                    obj=obj, attrib=attrib, arguments=arguments
-                )
-            else:
-                raise
+                    raise
 
 
 def return_related(instance, related_field):