Changes between Version 12 and Version 13 of new_meta_api

Timestamp:

Jul 11, 2014, 7:00:09 AM (10 years ago)

Author:

pirosb3

Comment:

--

new_meta_api

@@ -169 +169 @@
      <RelatedObject: admin:logentry related to user>)
 }}}
+
+===== get_field
+
+{{{
+    def get_field(self, field_name, m2m=True, data=True, related_m2m=False, related_objects=False, virtual=False)
+}}}
+
+'get_field' returns a field_instance from a given field name. field_name can be anything from name, attname and related_query name.
+get_field is recursive by default and does not include any hidden or proxied relations. There has still not been any reason to add these
+and they can be derived from 'get_fields'.
+If a given name is not found, it will raise a FieldDoesNotExist error.
+'get_field' is internally cached and gets all field information from 'get_fields' internally.
+
+NOTE: There is an inconsistency between the defaults of get_field and get_fields. 'get_fields' by default enables only data fields
+while 'get_field' by default enables data and m2m. This is because of backwards-compatibility issues (get_field already existed).
+
+{{{
+    >>> User._meta.get_new_field('username') # A data field
+    <django.db.models.fields.CharField: username>
+
+    >>> User._meta.get_new_field('logentry', related_objects=True) # A related object
+    <RelatedObject: admin:logentry related to user>
+
+    >>> LogEntry._meta.get_field('user') # ForeignKey can be queried by field name
+    <django.db.models.fields.related.ForeignKey: user>
+    >>> LogEntry._meta.get_field('user_id') # .. and also by database column name
+    <django.db.models.fields.related.ForeignKey: user>
+
+    >>> User._meta.get_new_field('does_not_exist') # A non existent field
+    *** FieldDoesNotExist: User has no field named 'does_not_exist'
+}}}