--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/utils/maxlength.py Fri Jul 18 18:22:23 2008 +0000
@@ -0,0 +1,65 @@
+"""
+Utilities for providing backwards compatibility for the maxlength argument,
+which has been replaced by max_length. See ticket #2101.
+"""
+
+from warnings import warn
+
+def get_maxlength(self):
+ return self.max_length
+
+def set_maxlength(self, value):
+ self.max_length = value
+
+def legacy_maxlength(max_length, maxlength):
+ """
+ Consolidates max_length and maxlength, providing backwards compatibilty
+ for the legacy "maxlength" argument.
+
+ If one of max_length or maxlength is given, then that value is returned.
+ If both are given, a TypeError is raised. If maxlength is used at all, a
+ deprecation warning is issued.
+ """
+ if maxlength is not None:
+ warn("maxlength is deprecated. Use max_length instead.", DeprecationWarning, stacklevel=3)
+ if max_length is not None:
+ raise TypeError("Field cannot take both the max_length argument and the legacy maxlength argument.")
+ max_length = maxlength
+ return max_length
+
+def remove_maxlength(func):
+ """
+ A decorator to be used on a class's __init__ that provides backwards
+ compatibilty for the legacy "maxlength" keyword argument, i.e.
+ name = models.CharField(maxlength=20)
+
+ It does this by changing the passed "maxlength" keyword argument
+ (if it exists) into a "max_length" keyword argument.
+ """
+ def inner(self, *args, **kwargs):
+ max_length = kwargs.get('max_length', None)
+ # pop maxlength because we don't want this going to __init__.
+ maxlength = kwargs.pop('maxlength', None)
+ max_length = legacy_maxlength(max_length, maxlength)
+ # Only set the max_length keyword argument if we got a value back.
+ if max_length is not None:
+ kwargs['max_length'] = max_length
+ func(self, *args, **kwargs)
+ return inner
+
+# This metaclass is used in two places, and should be removed when legacy
+# support for maxlength is dropped.
+# * oldforms.FormField
+# * db.models.fields.Field
+
+class LegacyMaxlength(type):
+ """
+ Metaclass for providing backwards compatibility support for the
+ "maxlength" keyword argument.
+ """
+ def __init__(cls, name, bases, attrs):
+ super(LegacyMaxlength, cls).__init__(name, bases, attrs)
+ # Decorate the class's __init__ to remove any maxlength keyword.
+ cls.__init__ = remove_maxlength(cls.__init__)
+ # Support accessing and setting to the legacy maxlength attribute.
+ cls.maxlength = property(get_maxlength, set_maxlength)