Add support for multiple languages

[davidcaron]

Overview

The 3 requests types are translated (GetCapabilities, DescribeProcess, Execute).

I translated only the title and abstract attributes for processes, inputs and outputs. Should something else be translated?

See the changes to docs/process.rst for an example of the interface.

Contribution Agreement

• I'd like to contribute this feature to PyWPS. I confirm that my contributions to PyWPS will be compatible with the PyWPS license guidelines at the time of contribution.
• I have already previously agreed to the PyWPS Contributions and Licensing Guidelines

[davidcaron]

Codacy complains about mutable default arguments (not in this PR) and TravisCI fails because http://test.opendap.org/opendap is down right now...

[davidcaron]

Here is an example of how we would add translations for a process and its inputs:

    from pywps import Process, LiteralInput, LiteralOutput


    class SayHello(Process):
        def __init__(self):
            inputs = [
                LiteralInput(
                    'name',
                    title='Input name',
                    abstract='The name to say hello to.',
                    translations={"fr-CA": {"abstract": "Le nom à saluer."}}
                )
            ],
            outputs=[
                LiteralOutput(
                    'response',
                    title='Output response',
                    abstract='The complete output message.',
                    translations={"fr-CA": {
                        "title": "La réponse", 
                        "abstract": "Le message complet."
                    }}
                )
            ],

            super().__init__(
                self._handler,
                identifier='say_hello',
                title='Process Say Hello',
                abstract='Returns a literal string output with Hello plus the inputed name',
                version='1.0',
                inputs=inputs,
                outputs=outputs,
                store_supported=True,
                status_supported=True,
                translations={"fr-CA": {
                    "title": "Processus Dire Bonjour", 
                    "abstract": "Retourne une chaine de caractères qui dit bonjour au nom fournit en entrée."
                }},
            )

@huard, do you think there could be a more intuitive way to specify the translations?

[huard]

@davidcaron I like the interface. It's close to the code, it obvious what to do. 👍

[coveralls]

Coverage increased (+0.5%) to 75.676% when pulling 6ac48ee on davidcaron:add-multiple-languages into a1c8502 on geopython:master.

[cehbrecht]

Looks good.

[cehbrecht]

tests are working now. I have checked for merge conflicts with PR #505 and there are none. Safe to merge.

[cehbrecht]

@davidcaron merged. Thanks for adding this :)