fix auth in wps

[cehbrecht]

This PR fixes #609 in the wps module. It keeps the old interface with verify only for the WebProcessingService class. Internally only the self.auth parameter should be used.

I have made a quick test with birdy.

[cehbrecht]

@eric-spitler @Tiranno Please give a comment.

[eric-spitler]

The WPS* classes already had the username|password|cert|verify arguments at the time of addition of the Authentication class. They were left in there for backward compatibility with the attempt to allow them to override the values in an Authentication instance (if needed) when using readFromUrl and such. It is certainly more consistent to enforce the use of auth=, but the changes here will be breaking changes for anyone using the original authentication methods.

There is a comment in the class docs about deprecation, but deprecated functionality needs to remain functional and produce warnings to the developer so they can make the necessary updates prior to removing the functionality altogether.

@cehbrecht - Does owslib have a development timeline for how long to keep deprecated functionality? Number of releases?

[eric-spitler]

Should really issue a DeprecationWarning here for some time before removing existing functionality to avoid breaking code.

Note that this means a two-phase change - one to add the DeprecationWarning, another later to remove the kwargs.

def readFromUrl(self, url, username=None, password=None, headers=None, verify=True, cert=None):
    import warnings
    message = 'The use of "username", "password", "verify", and "cert" is deprecated. ' + \
        'Please use the "auth" keyword during class instantiation. ' + \
        'These keywords will be removed in a future release.'
    warnings.warn(message, DeprecationWarning)
    # rest of the method

[cehbrecht]

I can add the deprecation warning in this PR.

I would have considered the WPSReader class as part of the internal interface. Though this is not obvious from the code.

[cehbrecht]

@tomkralidis Do you have recommendations on how to handle interface deprecations?

[tomkralidis]

@cehbrecht we have had such warnings in other parts of OWSLib (example: d4e26ea) for quite some time. Technically OWSLib is a pre 1.0 project so we have not gone the route of stable branch support (everything happens straight and away in master).

All to say I would leave deprecation handling (how long, etc.) up to the maintainer of the given code. We don't have an overall policy for OWSLib (yet) but perhaps this is a good time to make one).

[cehbrecht]

@eric-spitler @Tiranno @tomkralidis I have added the method _fix_auth which handles the deprecation warning. The interface is converted to the master branch version ... except that I use verify=None instead of verify=True.

[cehbrecht]

@tomkralidis Can I merge? It fixes at least the WPS for HTTPS ...

[tomkralidis]

@cehbrecht +1