terom@92: from werkzeug.wrappers import Request, Response
terom@92: from werkzeug.exceptions import (
terom@92:         HTTPException,
terom@92:         BadRequest,         # 400
terom@92:         NotFound,           # 404
terom@92: )
terom@92: from werkzeug.utils import redirect
terom@92: 
terom@92: class Application:
terom@92:     URLS = None
terom@92: 
terom@92:     def __init__ (self, urls=None):
terom@92:         """
terom@92:             urls        - werkzeug.routing.Map -> Handler
terom@92:         """
terom@92: 
terom@92:         if not urls:
terom@92:             urls = self.URLS
terom@92: 
terom@92:         if not urls:
terom@92:             raise ValueError("Required URLS/urls=...")
terom@92: 
terom@92:         self.urls = urls
terom@92: 
terom@103:     def lookup (self, request):
terom@92:         """
terom@103:             Lookup Request -> Handler, params
terom@92:         """
terom@92:         
terom@92:         # bind to request
terom@92:         urls = self.urls.bind_to_environ(request)
terom@92:         
terom@92:         # lookup
terom@92:         handler, params = urls.match()
terom@92: 
terom@92:         # handler instance
terom@92:         handler = handler(self, request, urls)
terom@103:         
terom@103:         return handler, params
terom@103:    
terom@103:     def respond (self, request):
terom@103:         """
terom@103:             Process Request -> Response, using lookup()
terom@103:         """
terom@103: 
terom@103:         handler, params = self.lookup(request)
terom@92: 
terom@92:         try :
terom@92:             handler.init()
terom@92: 
terom@92:             # apply
terom@92:             return handler.respond(**params)
terom@92: 
terom@92:         finally :
terom@92:             handler.cleanup()
terom@92: 
terom@92:     @Request.application
terom@92:     def __call__ (self, request) :
terom@92:         """
terom@92:             WSGI entry point, werkzeug Request -> Response
terom@92:         """
terom@92: 
terom@92:         try :
terom@92:             return self.respond(request)
terom@92:         
terom@92:         except HTTPException as ex :
terom@92:             return ex
terom@92: 
terom@92: class Handler (object) :
terom@92:     """
terom@92:         Per-Request controller/view, containing the request context and generating the response.
terom@92:     """
terom@92:     
terom@92:     # werkzeug defaults to UTF-8
terom@92:     MIMETYPE = 'text/html'
terom@92: 
terom@92:     def __init__ (self, app, request, urls) :
terom@92:         """
terom@92:             app     - wsgi.Application
terom@92:             request - werkzeug.Request
terom@92:             urls    - werkzeug.routing.Map.bind_to_environ()
terom@92:         """
terom@92: 
terom@92:         self.app = app
terom@92:         self.request = request
terom@92:         self.urls = urls
terom@92: 
terom@92:     def url (self, handler=None, **params) :
terom@92:         """
terom@92:             Return an URL for given endpoint, with parameters,
terom@92:         """
terom@92: 
terom@92:         if not handler :
terom@92:             handler = self.__class__
terom@92: 
terom@92:         return self.urls.build(handler, params)
terom@92: 
terom@92:     ## processing stages
terom@92:     def init (self) :
terom@92:         """
terom@92:             Initialize on request start.
terom@92:         """
terom@92: 
terom@92:         pass
terom@92: 
terom@92:     def process (self, **params) :
terom@92:         """
terom@92:             Process request args to build internal request state.
terom@92: 
terom@92:             May optionally return a Response, to e.g. redirect after POST.
terom@92:         """
terom@92: 
terom@92:         pass
terom@92: 
terom@92:     def render (self) :
terom@92:         """
terom@92:             Render response.
terom@92:         """
terom@92: 
terom@92:         raise NotImplementedError()
terom@92: 
terom@109:     def status (self):
terom@109:         return 200
terom@109: 
terom@109:     def headers (self):
terom@109:         return [ ]
terom@109:     
terom@92:     def mimetype (self):
terom@92:         return self.MIMETYPE
terom@92: 
terom@92: 
terom@92:     def respond (self, **params) :
terom@92:         """
terom@92:             Generate a response, or raise an HTTPException
terom@92:         """
terom@92:         
terom@92:         # returning e.g. redirect?
terom@92:         response = self.process(**params)
terom@92: 
terom@92:         if response :
terom@92:             return response
terom@92:         
terom@109:         return Response(self.render_response(), mimetype=self.mimetype(), status=self.status(), headers=self.headers())
terom@103: 
terom@92:     def cleanup (self) :
terom@92:         """
terom@92:             After request processing. Do not fail :)
terom@92:         """
terom@92:         
terom@92:         pass
terom@92: