openo-portal/portal-common/src/main/webapp/common/thirdparty/cometd/cometd/ReloadExtension.js

   1 /*\r
   2  * Copyright (c) 2010 the original author or authors.\r
   3  *\r
   4  * Licensed under the Apache License, Version 2.0 (the "License");\r
   5  * you may not use this file except in compliance with the License.\r
   6  * You may obtain a copy of the License at\r
   7  *\r
   8  *     http://www.apache.org/licenses/LICENSE-2.0\r
   9  *\r
  10  * Unless required by applicable law or agreed to in writing, software\r
  11  * distributed under the License is distributed on an "AS IS" BASIS,\r
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  13  * See the License for the specific language governing permissions and\r
  14  * limitations under the License.\r
  15  */\r
  16 \r
  17 (function()\r
  18 {\r
  19     function bind(org_cometd)\r
  20     {\r
  21         if (!org_cometd.COOKIE)\r
  22         {\r
  23             org_cometd.COOKIE = {};\r
  24             org_cometd.COOKIE.set = function(name, value, options)\r
  25             {\r
  26                 throw 'Abstract';\r
  27             };\r
  28             org_cometd.COOKIE.get = function(name)\r
  29             {\r
  30                 throw 'Abstract';\r
  31             };\r
  32         }\r
  33 \r
  34         /**\r
  35          * The reload extension allows a page to be loaded (or reloaded)\r
  36          * without having to re-handshake in the new (or reloaded) page,\r
  37          * therefore resuming the existing cometd connection.\r
  38          *\r
  39          * When the reload() method is called, the state of the cometd\r
  40          * connection and of the cometd subscriptions is stored in a cookie\r
  41          * with a short max-age.\r
  42          * The reload() method must therefore be called by page unload\r
  43          * handlers, often provided by JavaScript toolkits.\r
  44          *\r
  45          * When the page is (re)loaded, this extension checks the cookie\r
  46          * and restores the cometd connection and the cometd subscriptions.\r
  47          */\r
  48         return org_cometd.ReloadExtension = function(configuration)\r
  49         {\r
  50             var _cometd;\r
  51             var _debug;\r
  52             var _state = null;\r
  53             var _cookieName = 'org.cometd.reload';\r
  54             var _cookiePath = '/';\r
  55             var _cookieMaxAge = 5;\r
  56             var _batch = false;\r
  57 \r
  58             function _reload(config)\r
  59             {\r
  60                 if (_state && _state.handshakeResponse !== null)\r
  61                 {\r
  62                     _configure(config);\r
  63                     _state.cookiePath = _cookiePath;\r
  64                     var cookie = org_cometd.JSON.toJSON(_state);\r
  65                     _debug('Reload extension saving cookie value', cookie);\r
  66                     org_cometd.COOKIE.set(_cookieName, cookie, {\r
  67                         'max-age': _cookieMaxAge,\r
  68                         path: _cookiePath,\r
  69                         expires: new Date(new Date().getTime() + _cookieMaxAge * 1000)\r
  70                     });\r
  71                 }\r
  72             }\r
  73 \r
  74             function _similarState(oldState)\r
  75             {\r
  76                 // We want to check here that the CometD object\r
  77                 // did not change much between reloads.\r
  78                 // We just check the URL for now, but in future\r
  79                 // further checks may involve the transport type\r
  80                 // and other configuration parameters.\r
  81                 return _state.url == oldState.url;\r
  82             }\r
  83 \r
  84             function _configure(config)\r
  85             {\r
  86                 if (config)\r
  87                 {\r
  88                     if (typeof config.cookieMaxAge === 'number')\r
  89                     {\r
  90                         _cookieMaxAge = config.cookieMaxAge;\r
  91                     }\r
  92                     if (typeof config.cookieName === 'string')\r
  93                     {\r
  94                         _cookieName = config.cookieName;\r
  95                     }\r
  96                     if (typeof config.cookiePath === 'string')\r
  97                     {\r
  98                         _cookiePath = config.cookiePath;\r
  99                     }\r
 100                 }\r
 101             }\r
 102 \r
 103             this.configure = _configure;\r
 104 \r
 105             this.registered = function(name, cometd)\r
 106             {\r
 107                 _cometd = cometd;\r
 108                 _cometd.reload = _reload;\r
 109                 _debug = _cometd._debug;\r
 110             };\r
 111 \r
 112             this.unregistered = function()\r
 113             {\r
 114                 delete _cometd.reload;\r
 115                 _cometd = null;\r
 116             };\r
 117 \r
 118             this.outgoing = function(message)\r
 119             {\r
 120                 var channel = message.channel;\r
 121 \r
 122                 if (channel == '/meta/handshake')\r
 123                 {\r
 124                     _state = {};\r
 125                     _state.url = _cometd.getURL();\r
 126 \r
 127                     var cookie = org_cometd.COOKIE.get(_cookieName);\r
 128                     _debug('Reload extension found cookie value', cookie);\r
 129                     // Is there a saved handshake response from a prior load ?\r
 130                     if (cookie)\r
 131                     {\r
 132                         try\r
 133                         {\r
 134                             var oldState = org_cometd.JSON.fromJSON(cookie);\r
 135 \r
 136                             // Remove the cookie, not needed anymore\r
 137                             org_cometd.COOKIE.set(_cookieName, '', {\r
 138                                 'max-age': -1,\r
 139                                 path: oldState.cookiePath,\r
 140                                 expires: -1\r
 141                             });\r
 142 \r
 143                             if (oldState.handshakeResponse && _similarState(oldState))\r
 144                             {\r
 145                                 _debug('Reload extension restoring state', oldState);\r
 146                                 setTimeout(function()\r
 147                                 {\r
 148                                     _debug('Reload extension replaying handshake response', oldState.handshakeResponse);\r
 149                                     _state.handshakeResponse = oldState.handshakeResponse;\r
 150                                     _state.transportType = oldState.transportType;\r
 151                                     _state.reloading = true;\r
 152                                     var response = _cometd._mixin(true, {}, _state.handshakeResponse, {ext: {reload: true}});\r
 153                                     response.supportedConnectionTypes = [_state.transportType];\r
 154                                     _cometd.receive(response);\r
 155                                     _debug('Reload extension replayed handshake response', response);\r
 156                                 }, 0);\r
 157 \r
 158                                 // delay any sends until first connect is complete.\r
 159                                 if (!_batch)\r
 160                                 {\r
 161                                     _batch = true;\r
 162                                     _cometd.startBatch();\r
 163                                 }\r
 164                                 // This handshake is aborted, as we will replay the prior handshake response\r
 165                                 return null;\r
 166                             }\r
 167                             else\r
 168                             {\r
 169                                 _debug('Reload extension could not restore state', oldState);\r
 170                             }\r
 171                         }\r
 172                         catch(x)\r
 173                         {\r
 174                             _debug('Reload extension error while trying to restore cookie', x);\r
 175                         }\r
 176                     }\r
 177                 }\r
 178                 else if (channel == '/meta/connect')\r
 179                 {\r
 180                     if (!_state.transportType)\r
 181                     {\r
 182                         _state.transportType = message.connectionType;\r
 183                         _debug('Reload extension tracked transport type', _state.transportType);\r
 184                     }\r
 185                 }\r
 186                 return message;\r
 187             };\r
 188 \r
 189             this.incoming = function(message)\r
 190             {\r
 191                 if (message.successful)\r
 192                 {\r
 193                     switch (message.channel)\r
 194                     {\r
 195                         case '/meta/handshake':\r
 196                             // If the handshake response is already present, then we're replaying it.\r
 197                             // Since the replay may have modified the handshake response, do not record it here.\r
 198                             if (!_state.handshakeResponse)\r
 199                             {\r
 200                                 // Save successful handshake response\r
 201                                 _state.handshakeResponse = message;\r
 202                                 _debug('Reload extension tracked handshake response', message);\r
 203                             }\r
 204                             break;\r
 205                         case '/meta/disconnect':\r
 206                             _state = null;\r
 207                             break;\r
 208                         case '/meta/connect':\r
 209                             if (_batch)\r
 210                             {\r
 211                                 _cometd.endBatch();\r
 212                                 _batch = false;\r
 213                             }\r
 214                             break;\r
 215                         default:\r
 216                             break;\r
 217                     }\r
 218                 }\r
 219                 return message;\r
 220             };\r
 221 \r
 222             _configure(configuration);\r
 223         };\r
 224     }\r
 225 \r
 226     if (typeof define === 'function' && define.amd)\r
 227     {\r
 228         define(['org/cometd'], bind);\r
 229     }\r
 230     else\r
 231     {\r
 232         bind(org.cometd);\r
 233     }\r
 234 })();\r