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1 """ |
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2 WSGI Application. |
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3 """ |
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4 |
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5 import werkzeug |
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6 from werkzeug.wrappers import Request, Response |
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7 from werkzeug.exceptions import HTTPException |
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8 |
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9 import logging; log = logging.getLogger('pvl.web.application') |
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10 |
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11 class Application (object) : |
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12 """ |
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13 Main state. |
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14 """ |
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15 |
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16 URLS = None |
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17 |
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18 def __init__ (self, urls=None) : |
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19 """ |
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20 urls - werkzeug.routing.Map -> Handler |
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21 """ |
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22 |
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23 if not urls : |
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24 urls = self.URLS |
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25 |
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26 if not urls : |
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27 raise ValueError("No URLS/urls=... given") |
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28 |
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29 self.urls = urls |
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30 |
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31 def respond (self, request) : |
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32 """ |
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33 Lookup Request -> web.Handler, params |
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34 """ |
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35 |
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36 # bind to request |
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37 urls = self.urls.bind_to_environ(request) |
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38 |
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39 # lookup |
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40 handler, params = urls.match() |
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41 |
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42 # handler instance |
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43 handler = handler(self, request, urls, params) |
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44 |
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45 try : |
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46 # apply |
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47 return handler.respond() |
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48 |
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49 finally : |
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50 handler.cleanup() |
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51 |
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52 @Request.application |
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53 def __call__ (self, request) : |
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54 """ |
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55 WSGI entry point, werkzeug Request -> Response |
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56 """ |
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57 |
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58 try : |
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59 return self.respond(request) |
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60 |
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61 except HTTPException as ex : |
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62 return ex |
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63 |
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64 from pvl.invoke import merge # XXX |
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65 from pvl.web.html import tags as html |
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66 |
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67 class Handler (object) : |
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68 """ |
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69 Per-Request controller/view, containing the request context and generating the response. |
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70 """ |
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71 |
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72 TITLE = None |
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73 CSS = ( |
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74 #"/static/...css", |
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75 ) |
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76 JS = ( |
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77 #"/static/....js" |
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78 ) |
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79 |
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80 def __init__ (self, app, request, urls, params) : |
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81 """ |
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82 app - wsgi.Application |
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83 request - werkzeug.Request |
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84 urls - werkzeug.routing.Map.bind_to_environ() |
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85 """ |
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86 |
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87 self.app = app |
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88 self.request = request |
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89 self.urls = urls |
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90 self.params = params |
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91 |
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92 def url (self, handler=None, **params) : |
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93 """ |
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94 Return an URL for given endpoint, with parameters, |
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95 """ |
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96 |
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97 if not handler : |
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98 # XXX: just generate a plain-relative '?foo=...' url instead? |
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99 handler = self.__class__ |
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100 params = merge(self.params, params) |
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101 |
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102 return self.urls.build(handler, params) |
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103 |
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104 def title (self) : |
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105 """ |
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106 Render site/page title as text. |
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107 """ |
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108 |
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109 return self.TITLE |
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110 |
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111 def render (self) : |
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112 """ |
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113 Render page content (as <body>...</body>). |
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114 """ |
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115 |
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116 raise NotImplementedError() |
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117 |
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118 def render_html (self) : |
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119 """ |
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120 Render page layout (as <html>). |
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121 """ |
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122 |
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123 title = self.title() |
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124 |
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125 return html.html( |
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126 html.head( |
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127 html.title(title), |
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128 ( |
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129 html.link(rel='Stylesheet', type="text/css", href=src) for src in self.CSS |
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130 ), |
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131 ( |
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132 html.script(src=src, type='text/javascript', _selfclosing=False) for src in self.JS |
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133 ), |
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134 ), |
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135 html.body( |
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136 html.h1(title), |
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137 self.render() |
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138 ) |
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139 ) |
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140 |
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141 def process (self, **params) : |
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142 """ |
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143 Process request args to build internal request state. |
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144 """ |
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145 |
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146 pass |
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147 |
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148 def respond (self) : |
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149 """ |
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150 Generate a response, or raise an HTTPException |
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151 |
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152 Does an HTML layout'd response per default. |
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153 """ |
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154 |
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155 # returning e.g. redirect? |
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156 response = self.process(**self.params) |
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157 |
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158 if response : |
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159 return response |
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160 |
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161 # render as html per default |
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162 render = self.render_html() |
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163 text = unicode(html.document(render)) |
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164 |
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165 return Response(text, mimetype='text/html') |
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166 |
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167 def cleanup (self) : |
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168 """ |
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169 After request processing. Do not fail :) |
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170 """ |
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171 |
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172 pass |