Invalid regexp in URLValidator can't handle file:// schemes

[Marcin Nowak]

Regexp does not allow to use file scheme in URLValidator.

Steps to reproduce

from django.core.validators import URLValidator
URLValidator(schemes=['file'])('file:///tmp/somefile')

Expected result

No exception should be raised.

Current result

ValidationError: [u'Enter a valid URL.']

[Tim Graham]

Can this be fixed without special casing the file scheme in the validation?

[Claude Paroz]

It's URLValidator not URIValidator, I think you might need your own custom validator for this. The current regex is already bloated, I'm not sure we should continue to complexify it...

[Tim Graham]

I had a similar skepticism. If we don't make a change, then let's clarify the documentation to prevent further tickets about this.

[Johannes Maron]

I thinks this is both a documentation and code problem. The URLValidator should raise a value error, if a unsupported schema is set. In the documentation it should be explained with RFC 1738 schemas are supported. Currently one gets the impression that all are.

[Johannes Maron]

Interestingly enough, if you include the optional host parameter in RFC1738 it works: file://localhost/tmp/file/name