/**
* Copyright (C) 2005-2016 Alfresco Software Limited.
*
* This file is part of Alfresco
*
* Alfresco is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Alfresco is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Singleton providing class for handling publications. This allows publications to be queued whilst all the
* widgets on the page are created. The overall [page widget]{@link module:alfresco/core/Page} will then "release"
* all the publications once the widgets are ready to process them.
*
* @module alfresco/core/PubQueue
* @author Dave Draper
*/
define(["dojo/_base/declare",
"dojo/_base/lang",
"dojo/_base/array",
"dojo/topic",
"alfresco/core/PubSubLog",
"service/constants/Default"],
function(declare, lang, array, pubSub, PubSubLog, AlfConstants) {
// This is a simple singleton pattern. Technically it is still possible to instantiate a new log,
// but as the core will always use the singleton and it is expected that all calls will go through the core
// then this shouldn't be a problem...
var PubQueue = declare(null, {
/**
* Indicates whether or not the publications have been released. This is set from false to true
* when the [release]{@link module:alfresco/core/PubQueue#release} function is called and will result
* in publications no longer being queue but being published immediated
*
* @instance
* @type {boolean}
* @default
*/
_released: false,
/**
* To make sure that all publications are made in order after releasing, this flag is used to indicate
* that all queued publications have been made before publishing resulting publications. An example of this
* would be where a queued publication triggers another publication - it is imperative that this resulting
* publication does not "jump the queue". Instead it should itself be queued and wait for its turn.
*
* @instance
* @type {boolean}
* @default
* @since 1.0.65
*/
_unreleasedEmptied: false,
/**
* @instance
* @type {array}
* @default []
*/
_queue: [],
/**
* It is possible for multiple Surf Components to exist on a browser page where each Surf Component is creating
* a new Aikau page. In order for the PubQueue to only allow the release of publications once all pages have
* finished being created it is necessary to track the number of pages being rendered. This counter is
* incremented with every call to [registerPage]{@link module:alfresco/core/PubQueue#registerPage} and
* decremented with every call to [release]{@link module:alfresco/core/PubQueue#release}. See AKU-965 for more
* information.
*
* @instance
* @type {number}
* @default
* @since 1.0.68
*/
_pageCount: 0,
/**
* This function should only be called from the [Page]{@link module:alfresco/core/Page} widget before the page
* is constructed. It increments the [_pageCount]{@link module:alfresco/core/PubQueue#_pageCount} counter to ensure
* that all pages finish rendering before publications are released.
*
* @instance
* @since 1.0.68
*/
registerPage: function alfresco_core_PubQueue__registerPage() {
this._pageCount++;
this._released = false;
this._unreleasedEmptied = false;
},
/**
* @instance
* @param {string} scopedTopic The topic to publish on
* @param {string} payload The payload to be delivered
*/
publish: function alfresco_core_PubQueue__publish(scopedTopic, payload, caller) {
if (this._released === false || this._unreleasedEmptied === false)
{
this._queue.push({
topic: scopedTopic,
payload: payload,
caller: caller
});
}
else
{
this.log(scopedTopic, payload, caller);
pubSub.publish(scopedTopic, payload);
}
},
/**
* Iterates over the queued publications and publishes them.
*
* @instance
*/
release: function alfresco_core_PubQueue__release() {
this._pageCount--;
if (this._pageCount === 0)
{
this._released = true;
var publication = this._queue.shift();
while (publication)
{
this.log(publication.topic, publication.payload, publication.caller);
pubSub.publish(publication.topic, publication.payload);
publication = this._queue.shift();
}
this._unreleasedEmptied = true;
}
},
/**
* Logs the publication if the publication to be logged isn't a log request or
* a request to log publications or subscriptions.
*
* @param {string} scopedTopic The topic to publish on
* @param {object} payload The payload to be delivered
* @param {object} caller The widget or service requesting the publication
*/
log: function alfresco_core_PubQueue__log(scopedTopic, payload, caller) {
if (scopedTopic && (scopedTopic !== "ALF_LOG_REQUEST" &&
scopedTopic !== "ALF_LOG_PUBLICATION_ACTIVITY" &&
scopedTopic !== "ALF_LOG_SUBSCRIPTION_ACTIVITY" &&
scopedTopic !== "ALF_LOG_UNSUBSCRIPTION_ACTIVITY"))
{
if (AlfConstants.DEBUG === true)
{
PubSubLog.getSingleton().pub(scopedTopic, payload, caller);
pubSub.publish("ALF_LOG_PUBLICATION_ACTIVITY", payload, caller);
}
}
}
});
var instance;
PubQueue.getSingleton = function() {
if (!instance)
{
instance = new PubQueue();
}
return instance;
};
return PubQueue;
});
Alfresco Aikau Widgets