Fix according to review comments.

pdc/apps/component/serializers.py

@@ -541,40 +541,13 @@ class Meta:
         fields = ('id', 'type', 'from_component', 'to_component')
 
 
-def _check_role_count(component_contact_model, component, role):
-    current_role_count = component_contact_model.objects.filter(component=component, role=role).count()
-    if role.count_limit != ContactRole.UNLIMITED and current_role_count >= role.count_limit:
-        raise serializers.ValidationError({
-            'detail': 'Exceed contact role limit for the component. The limit is %d' % role.count_limit})
-
-
-def validate_component_role_count(component_contact_model, value, instance):
-    role = value.get('role')
-    component = value.get('component')
-    # POST with role
-    if not instance and role:
-        _check_role_count(component_contact_model, component, role)
-
-    # PUT or PATCH
-    else:
-        if (role and role != instance.role) or (component and component != instance.component):
-            # with model unique restriction, it will increase 1 to destination component's role count.
-            role = role if role else instance.role
-            component = component if component else instance.component
-            _check_role_count(component_contact_model, component, role)
-
-
 class GlobalComponentContactSerializer(StrictSerializerMixin, serializers.ModelSerializer):
     component = serializers.SlugRelatedField(slug_field='name', read_only=False,
                                              queryset=GlobalComponent.objects.all())
     role = serializers.SlugRelatedField(slug_field='name', read_only=False,
                                         queryset=ContactRole.objects.all())
     contact = ContactField()
 
-    def validate(self, value):
-        validate_component_role_count(GlobalComponentContact, value, self.instance)
-        return value
-
     class Meta:
         model = GlobalComponentContact
         fields = ('id', 'component', 'role', 'contact')
@@ -587,10 +560,6 @@ class ReleaseComponentContactSerializer(StrictSerializerMixin, serializers.Model
                                         queryset=ContactRole.objects.all())
     contact = ContactField()
 
-    def validate(self, value):
-        validate_component_role_count(ReleaseComponentContact, value, self.instance)
-        return value
-
     class Meta:
         model = ReleaseComponentContact
         fields = ('id', 'component', 'role', 'contact')

pdc/apps/contact/models.py

@@ -8,6 +8,7 @@
 from django.db import models
 from django.db.models.query import QuerySet
 from django.forms.models import model_to_dict
+from django.core.exceptions import ValidationError
 
 
 class ContactRole(models.Model):
@@ -144,7 +145,27 @@ def create(self, **kwargs):
         return self.get_queryset().create(**create_kwargs)
 
 
-class GlobalComponentContact(models.Model):
+class ValidateRoleCountMixin(object):
+
+    def _check_role_count(self):
+        current_role_count = type(self).objects.filter(component=self.component, role=self.role).count()
+        if self.role.count_limit != ContactRole.UNLIMITED and current_role_count >= self.role.count_limit:
+            raise ValidationError(
+                {'detail': 'Exceed contact role limit for the component. The limit is %d' % self.role.count_limit})
+
+    def clean(self):
+        # Create
+        if not self.pk:
+            self._check_role_count()
+        # Update
+        else:
+            old_instance = type(self).objects.get(pk=self.pk)
+            if self.role != old_instance.role or self.component != old_instance.component:
+                # with model unique restriction, it will increase 1 to destination component's role count.
+                self._check_role_count()
+
+
+class GlobalComponentContact(ValidateRoleCountMixin, models.Model):
 
     role      = models.ForeignKey(ContactRole, on_delete=models.PROTECT)
     contact   = models.ForeignKey(Contact, on_delete=models.PROTECT)
@@ -165,15 +186,15 @@ def export(self, fields=None):
         }
 
 
-class ReleaseComponentContact(models.Model):
+class ReleaseComponentContact(ValidateRoleCountMixin, models.Model):
 
     role      = models.ForeignKey(ContactRole, on_delete=models.PROTECT)
     contact   = models.ForeignKey(Contact, on_delete=models.PROTECT)
     component = models.ForeignKey('component.ReleaseComponent',
                                   on_delete=models.PROTECT)
 
     def __unicode__(self):
-        return u'%s: %s: %s' % (unicode(self.component), self.contact_role, unicode(self.contact))
+        return u'%s: %s: %s' % (unicode(self.component), self.role, unicode(self.contact))
 
     class Meta:
         unique_together = (('role', 'component', 'contact'), )

pdc/apps/contact/serializers.py

@@ -20,7 +20,7 @@ class ContactRoleSerializer(StrictSerializerMixin,
 
     class Meta:
         model = ContactRole
-        fields = ('name', )
+        fields = ('name', 'count_limit')
 
 
 class PersonSerializer(DynamicFieldsSerializerMixin,