Show undefined variable errors in Django templates?

Question

How can I ask Django to tell me when it encounters, for example, an undefined variable error while it\'s rendering templates?

I\'ve tried the obvious DEBUG = T

Answer 1

Put this in your debug settings:

class InvalidString(str):
    def __mod__(self, other):
        from django.template.base import TemplateSyntaxError
        raise TemplateSyntaxError(
            "Undefined variable or unknown value for: \"%s\"" % other)

TEMPLATE_STRING_IF_INVALID = InvalidString("%s")

This should raise an error when the template engine sees or finds an undefined value.