Can't use apispec tornado plugin icw complex paths

[lafrech]

Issue by p0psicles Monday Dec 11, 2017 at 19:41 GMT Originally opened as https://github.com/marshmallow-code/apispec/issues/176

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I'm trying to use apispec icw the 'apispec.ext.tornado' and 'apispec.ext.marshmallow' plugins. Only i'm getting the following error:

Traceback (most recent call last):
  File "D:\JetBrains\PyCharm 2017.2.4\helpers\pydev\pydevd.py", line 1599, in <module>
    globals = debugger.run(setup['file'], None, None, is_module)
  File "D:\JetBrains\PyCharm 2017.2.4\helpers\pydev\pydevd.py", line 1026, in run
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "D:\myproj/start.py", line 7, in <module>
    main()
  File "D:\myproj\medusa\__main__.py", line 2104, in main
    application.start(sys.argv[1:])
  File "D:\myproj\medusa\__main__.py", line 347, in start
    self.web_server = AppWebServer(self.web_options)
  File "D:\myproj\medusa\server\core.py", line 230, in __init__
    spec.add_path(urlspec=urlspec)
  File "D:\Python27\lib\site-packages\apispec\core.py", line 211, in add_path
    raise APISpecError('Path template is not specified')
apispec.exceptions.APISpecError: Path template is not specified

It seems to be happening because matcher._path is None. https://github.com/marshmallow-code/apispec/blob/dev/apispec/ext/tornado.py#L95

urlspec.matcher._path returns None, because of this: https://github.com/tornadoweb/tornado/blob/master/tornado/routing.py#L571

And my route looks like this: '/api/v2/series/(?P<series_slug>\\w+)/episode(?:(?:(?:(?:/(?P<episode_slug>[\\w-]+))|/?)(?:(?:/(?P<path_param>\\w+))|/?))|/?)/?$'

So because the tornado plugin uses the matcher._path, it's can't translate to an OpenApi compliant path. Is there anything I can do about it?