add support for ``is_created`` to inline forms

flask_admin/contrib/mongoengine/fields.py

@@ -36,13 +36,14 @@ class ModelFormField(InlineFormField):
 
     def populate_obj(self, obj, name):
         candidate = getattr(obj, name, None)
-        if candidate is None:
+        is_created = candidate is None
+        if is_created:
             candidate = self.model()
             setattr(obj, name, candidate)
 
         self.form.populate_obj(candidate)
 
-        self.view.on_model_change(self.form, candidate)
+        self.view._on_model_change(self.form, candidate, is_created)
 
 
 class MongoFileField(fields.FileField):

flask_admin/contrib/peewee/form.py

@@ -61,7 +61,8 @@ class InlineModelFormList(InlineFieldList):
         for field in self.entries:
             field_id = field.get_pk()
 
-            if field_id in pk_map:
+            is_created = field_id not in pk_map
+            if not is_created:
                 model = pk_map[field_id]
 
                 if self.should_delete(field):
@@ -75,7 +76,7 @@ class InlineModelFormList(InlineFieldList):
             # Force relation
             setattr(model, self.prop, model_id)
 
-            self.inline_view.on_model_change(field, model)
+            self.inline_view._on_model_change(field, model, is_created)
 
             model.save()
 

flask_admin/contrib/sqla/fields.py

@@ -279,7 +279,8 @@ class InlineModelFormList(InlineFieldList):
         for field in self.entries:
             field_id = field.get_pk()
 
-            if field_id in pk_map:
+            is_created = field_id not in pk_map
+            if not is_created:
                 model = pk_map[field_id]
 
                 if self.should_delete(field):
@@ -291,7 +292,7 @@ class InlineModelFormList(InlineFieldList):
 
             field.populate_obj(model, None)
 
-            self.inline_view.on_model_change(field, model)
+            self.inline_view._on_model_change(field, model, is_created)
 
 
 def get_pk_from_identity(obj):

flask_admin/model/form.py

 import inspect
+import warnings
 
 from flask_admin.form import BaseForm, rules
 from flask_admin._compat import iteritems
@@ -107,7 +108,7 @@ class InlineBaseFormAdmin(object):
         """
         return form_class
 
-    def on_model_change(self, form, model):
+    def on_model_change(self, form, model, is_created):
         """
             Called when inline model is about to be saved.
 
@@ -115,9 +116,24 @@ class InlineBaseFormAdmin(object):
                 Inline form
             :param model:
                 Model
+            :param is_created:
+                Will be set to True if the model is being created, False if edited
         """
         pass
 
+    def _on_model_change(self, form, model, is_created):
+        """
+            Compatibility helper.
+        """
+        try:
+            self.on_model_change(form, model, is_created)
+        except TypeError:
+            msg = ('%s.on_model_change() now accepts third ' +
+                   'parameter is_created. Please update your code') % self.model
+            warnings.warn(msg)
+
+            self.on_model_change(form, model)
+
 
 class InlineFormAdmin(InlineBaseFormAdmin):
     """