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Diffstat (limited to 'common/src/main/webapp/thirdparty/cometd/cometd/ReloadExtension.js')
| -rw-r--r-- | common/src/main/webapp/thirdparty/cometd/cometd/ReloadExtension.js | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/common/src/main/webapp/thirdparty/cometd/cometd/ReloadExtension.js b/common/src/main/webapp/thirdparty/cometd/cometd/ReloadExtension.js new file mode 100644 index 0000000..ef6de78 --- /dev/null +++ b/common/src/main/webapp/thirdparty/cometd/cometd/ReloadExtension.js @@ -0,0 +1,234 @@ +/* + * Copyright (c) 2010 the original author or authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +(function() +{ + function bind(org_cometd) + { + if (!org_cometd.COOKIE) + { + org_cometd.COOKIE = {}; + org_cometd.COOKIE.set = function(name, value, options) + { + throw 'Abstract'; + }; + org_cometd.COOKIE.get = function(name) + { + throw 'Abstract'; + }; + } + + /** + * The reload extension allows a page to be loaded (or reloaded) + * without having to re-handshake in the new (or reloaded) page, + * therefore resuming the existing cometd connection. + * + * When the reload() method is called, the state of the cometd + * connection and of the cometd subscriptions is stored in a cookie + * with a short max-age. + * The reload() method must therefore be called by page unload + * handlers, often provided by JavaScript toolkits. + * + * When the page is (re)loaded, this extension checks the cookie + * and restores the cometd connection and the cometd subscriptions. + */ + return org_cometd.ReloadExtension = function(configuration) + { + var _cometd; + var _debug; + var _state = null; + var _cookieName = 'org.cometd.reload'; + var _cookiePath = '/'; + var _cookieMaxAge = 5; + var _batch = false; + + function _reload(config) + { + if (_state && _state.handshakeResponse !== null) + { + _configure(config); + _state.cookiePath = _cookiePath; + var cookie = org_cometd.JSON.toJSON(_state); + _debug('Reload extension saving cookie value', cookie); + org_cometd.COOKIE.set(_cookieName, cookie, { + 'max-age': _cookieMaxAge, + path: _cookiePath, + expires: new Date(new Date().getTime() + _cookieMaxAge * 1000) + }); + } + } + + function _similarState(oldState) + { + // We want to check here that the CometD object + // did not change much between reloads. + // We just check the URL for now, but in future + // further checks may involve the transport type + // and other configuration parameters. + return _state.url == oldState.url; + } + + function _configure(config) + { + if (config) + { + if (typeof config.cookieMaxAge === 'number') + { + _cookieMaxAge = config.cookieMaxAge; + } + if (typeof config.cookieName === 'string') + { + _cookieName = config.cookieName; + } + if (typeof config.cookiePath === 'string') + { + _cookiePath = config.cookiePath; + } + } + } + + this.configure = _configure; + + this.registered = function(name, cometd) + { + _cometd = cometd; + _cometd.reload = _reload; + _debug = _cometd._debug; + }; + + this.unregistered = function() + { + delete _cometd.reload; + _cometd = null; + }; + + this.outgoing = function(message) + { + var channel = message.channel; + + if (channel == '/meta/handshake') + { + _state = {}; + _state.url = _cometd.getURL(); + + var cookie = org_cometd.COOKIE.get(_cookieName); + _debug('Reload extension found cookie value', cookie); + // Is there a saved handshake response from a prior load ? + if (cookie) + { + try + { + var oldState = org_cometd.JSON.fromJSON(cookie); + + // Remove the cookie, not needed anymore + org_cometd.COOKIE.set(_cookieName, '', { + 'max-age': -1, + path: oldState.cookiePath, + expires: -1 + }); + + if (oldState.handshakeResponse && _similarState(oldState)) + { + _debug('Reload extension restoring state', oldState); + setTimeout(function() + { + _debug('Reload extension replaying handshake response', oldState.handshakeResponse); + _state.handshakeResponse = oldState.handshakeResponse; + _state.transportType = oldState.transportType; + _state.reloading = true; + var response = _cometd._mixin(true, {}, _state.handshakeResponse, {ext: {reload: true}}); + response.supportedConnectionTypes = [_state.transportType]; + _cometd.receive(response); + _debug('Reload extension replayed handshake response', response); + }, 0); + + // delay any sends until first connect is complete. + if (!_batch) + { + _batch = true; + _cometd.startBatch(); + } + // This handshake is aborted, as we will replay the prior handshake response + return null; + } + else + { + _debug('Reload extension could not restore state', oldState); + } + } + catch(x) + { + _debug('Reload extension error while trying to restore cookie', x); + } + } + } + else if (channel == '/meta/connect') + { + if (!_state.transportType) + { + _state.transportType = message.connectionType; + _debug('Reload extension tracked transport type', _state.transportType); + } + } + return message; + }; + + this.incoming = function(message) + { + if (message.successful) + { + switch (message.channel) + { + case '/meta/handshake': + // If the handshake response is already present, then we're replaying it. + // Since the replay may have modified the handshake response, do not record it here. + if (!_state.handshakeResponse) + { + // Save successful handshake response + _state.handshakeResponse = message; + _debug('Reload extension tracked handshake response', message); + } + break; + case '/meta/disconnect': + _state = null; + break; + case '/meta/connect': + if (_batch) + { + _cometd.endBatch(); + _batch = false; + } + break; + default: + break; + } + } + return message; + }; + + _configure(configuration); + }; + } + + if (typeof define === 'function' && define.amd) + { + define(['org/cometd'], bind); + } + else + { + bind(org.cometd); + } +})(); |