| 57 | | |
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| 58 | | |
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| 59 | | # Internal Redirect # |
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| 60 | | |
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| 61 | | |
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| 62 | | class InternalRedirector(object): |
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| 63 | | """WSGI middleware which handles cherrypy.InternalRedirect. |
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| 64 | | |
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| 65 | | When cherrypy.InternalRedirect is raised, this middleware traps it, |
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| 66 | | rewrites the WSGI environ using the new path and query_string, |
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| 67 | | and calls the next application again. Because the wsgi.input stream |
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| 68 | | may have already been consumed by the next application, the redirected |
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| 69 | | call will always be of HTTP method "GET", and therefore any params must |
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| 70 | | be passed in the InternalRedirect object's query_string attribute. |
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| 71 | | If you need something more complicated, make and raise your own |
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| 72 | | exception and your own WSGI middleware to trap it. ;) |
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| 73 | | |
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| 74 | | It would be a bad idea to raise InternalRedirect after you've already |
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| 75 | | yielded response content, although an enterprising soul could choose |
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| 76 | | to abuse this. |
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| 77 | | |
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| 78 | | nextapp: the next application callable in the WSGI chain. |
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| 79 | | |
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| 80 | | recursive: if False (the default), each URL (path + qs) will be |
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| 81 | | stored, and, if the same URL is requested again, RuntimeError will |
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| 82 | | be raised. If 'recursive' is True, no such error will be raised. |
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| 83 | | """ |
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| 84 | | |
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| 85 | | def __init__(self, nextapp, recursive=False): |
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| 86 | | self.nextapp = nextapp |
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| 87 | | self.recursive = recursive |
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| 88 | | |
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| 89 | | def __call__(self, environ, start_response): |
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| 90 | | return IRResponse(self.nextapp, environ, start_response, self.recursive) |
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| 91 | | |
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| 92 | | |
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| 93 | | class IRResponse(object): |
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| 94 | | |
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| 95 | | def __init__(self, nextapp, environ, start_response, recursive): |
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| 96 | | self.redirections = [] |
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| 97 | | self.recursive = recursive |
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| 98 | | self.environ = environ.copy() |
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| 99 | | self.nextapp = nextapp |
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| 100 | | self.start_response = start_response |
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| 101 | | self.response = None |
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| 102 | | self.iter_response = None |
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| 103 | | self.setapp() |
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| 104 | | |
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| 105 | | def setapp(self): |
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| 106 | | while True: |
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| 107 | | try: |
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| 108 | | self.response = self.nextapp(self.environ, self.start_response) |
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| 109 | | self.iter_response = iter(self.response) |
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| 110 | | return |
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| 111 | | except _cherrypy.InternalRedirect, ir: |
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| 112 | | self.close() |
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| 113 | | self.setenv(ir) |
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| 114 | | |
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| 115 | | def setenv(self, ir): |
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| 116 | | env = self.environ |
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| 117 | | if not self.recursive: |
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| 118 | | if ir.path in self.redirections: |
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| 119 | | raise RuntimeError("InternalRedirector visited the " |
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| 120 | | "same URL twice: %r" % ir.path) |
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| 121 | | else: |
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| 122 | | # Add the *previous* path_info + qs to redirections. |
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| 123 | | sn = env.get('SCRIPT_NAME', '') |
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| 124 | | path = env.get('PATH_INFO', '') |
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| 125 | | qs = env.get('QUERY_STRING', '') |
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| 126 | | if qs: |
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| 127 | | qs = "?" + qs |
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| 128 | | self.redirections.append(_http.urljoin(sn, path) + qs) |
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| 129 | | |
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| 130 | | # Munge environment and try again. |
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| 131 | | env['REQUEST_METHOD'] = "GET" |
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| 132 | | env['PATH_INFO'] = ir.path |
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| 133 | | env['QUERY_STRING'] = ir.query_string |
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| 134 | | env['wsgi.input'] = _StringIO.StringIO() |
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| 135 | | env['CONTENT_LENGTH'] = "0" |
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| 136 | | |
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| 137 | | def close(self): |
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| 138 | | if hasattr(self.response, "close"): |
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| 139 | | self.response.close() |
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| 140 | | |
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| 141 | | def __iter__(self): |
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| 142 | | return self |
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| 143 | | |
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| 144 | | def next(self): |
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| 145 | | while True: |
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| 146 | | try: |
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| 147 | | return self.iter_response.next() |
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| 148 | | except _cherrypy.InternalRedirect, ir: |
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| 149 | | self.close() |
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| 150 | | self.setenv(ir) |
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| 151 | | self.setapp() |
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