Add SerializerMethodField

1 files changed, 14 insertions, 0 deletions

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index c68c39b5..d1e9c45d 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -1019,3 +1019,17 @@ class ImageField(FileField):
         if hasattr(f, 'seek') and callable(f.seek):
             f.seek(0)
         return f
+
+
+class SerializerMethodField(Field):
+    """
+    A field that gets its value by calling a method on the serializer it's attached to.
+    """
+
+    def __init__(self, method_name):
+        self.method_name = method_name
+        super(SerializerMethodField, self).__init__()
+
+    def field_to_native(self, obj, field_name):
+        value = getattr(self.parent, self.method_name)(obj)
+        return self.to_native(value)