Form fields should use textual only value representations. Closes #3139…

…. Closes #2416. Closes #2558.

rest_framework/renderers.py

@@ -318,6 +318,9 @@ def render_field(self, field, parent_style):
             style['template_pack'] = parent_style.get('template_pack', self.template_pack)
         style['renderer'] = self
 
+        # Get a clone of the field with text-only value representation.
+        field = field.as_form_field()
+
         if style.get('input_type') == 'datetime-local' and isinstance(field.value, six.text_type):
             field.value = field.value.rstrip('Z')
 

rest_framework/utils/serializer_helpers.py

@@ -2,7 +2,7 @@
 
 import collections
 
-from rest_framework.compat import OrderedDict, unicode_to_repr
+from rest_framework.compat import OrderedDict, force_text, unicode_to_repr
 
 
 class ReturnDict(OrderedDict):
@@ -54,6 +54,7 @@ class BoundField(object):
     """
     def __init__(self, field, value, errors, prefix=''):
         self._field = field
+        self._prefix = prefix
         self.value = value
         self.errors = errors
         self.name = prefix + self.field_name
@@ -70,6 +71,9 @@ def __repr__(self):
             self.__class__.__name__, self.value, self.errors
         ))
 
+    def as_form_field(self):
+        return BoundField(self._field, force_text(self.value), self.errors, self._prefix)
+
 
 class NestedBoundField(BoundField):
     """