265 lines
8.9 KiB
JavaScript
265 lines
8.9 KiB
JavaScript
/**
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* PeriodicalUpdater - jQuery plugin for timed, decaying ajax calls
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*
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* http://www.360innovate.co.uk/blog/2009/03/periodicalupdater-for-jquery/
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* http://enfranchisedmind.com/blog/posts/jquery-periodicalupdater-ajax-polling/
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*
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* Copyright (c) 2009-2012 by the following:
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* Frank White (http://customcode.info)
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* Robert Fischer (http://smokejumperit.com)
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* 360innovate (http://www.360innovate.co.uk)
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*
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* Dual licensed under the MIT and GPL licenses:
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* http://www.opensource.org/licenses/mit-license.php
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* http://www.gnu.org/licenses/gpl.html
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*
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*/
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(function ($) {
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// The free version
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$.PeriodicalUpdater = function(url, options, callback){
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if(!options) options = {};
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var settings = jQuery.extend(true, {
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url: url, // URL of ajax request
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cache: false, // By default, don't allow caching
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method: 'GET', // method; get or post
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data: '', // array of values to be passed to the page - e.g. {name: "John", greeting: "hello"}
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minTimeout: 1000, // starting value for the timeout in milliseconds
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maxTimeout:64000, // maximum length of time between requests
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multiplier: 2, // if set to 2, timerInterval will double each time the response hasn't changed (up to maxTimeout)
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maxCalls: 0, // maximum number of calls. 0 = no limit.
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autoStop: 0, // automatically stop requests after this many returns of the same data. 0 = disabled
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autoStopCallback: null, // The callback to execute when we autoStop
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cookie: false, // whether (and how) to store a cookie
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runatonce: false, // Whether to fire initially or wait
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verbose: 0 // The level to be logging at: 0 = none; 1 = some; 2 = all
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}, options);
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var pu_log = function (msg, lvl) {
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lvl = lvl || 1;
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if(settings.verbose >= lvl) {
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try {
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console.log(msg);
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} catch (err) { }
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}
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};
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// set some initial values, then begin
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var timer = null;
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var remoteData = null;
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var prevData = null;
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var timerInterval = settings.minTimeout;
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var maxCalls = settings.maxCalls;
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var autoStop = settings.autoStop;
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var calls = 0;
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var noChange = 0;
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var originalMaxCalls = maxCalls;
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// Function to reset the timer to a given time
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var reset_timer = function (interval) {
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$(function() { // Ensure we're live
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if (timer !== null) {
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clearTimeout(timer);
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}
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timerInterval = interval;
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pu_log('resetting timer to ' + timerInterval + '.', 2);
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if(settings.cookie && $.cookie) {
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$.cookie(settings.cookie.name, timerInterval, settings.cookie);
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}
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timer = setTimeout(getdata, timerInterval);
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});
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};
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// Function to boost the timer
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var boostPeriod = function () {
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if (settings.multiplier > 1) {
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var before = timerInterval;
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timerInterval = timerInterval * settings.multiplier;
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if (timerInterval > settings.maxTimeout) {
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timerInterval = settings.maxTimeout;
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}
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pu_log('adjusting timer from ' + before + ' to ' + timerInterval + '.', 2);
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}
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reset_timer(timerInterval);
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};
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// Handle the cookie config
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if(settings.cookie) {
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if(typeof(settings.cookie) == 'boolean') {
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settings.cookie = {
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name: url
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};
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} else if(typeof(settings.cookie) != 'object') {
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settings.cookie = {
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name: settings.cookie.toString()
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};
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}
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if(!settings.cookie.name) {
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settings.cookie.name = url;
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}
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if(!$.cookie) {
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$.getScript("https://raw.github.com/carhartl/jquery-cookie/master/jquery.cookie.js", function() {
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pu_log("Loaded the cookies handler script", 2);
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if($.cookie(settings.cookie.name)) {
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pu_log("Not runatonce and have cookie value", 2);
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reset_timer($.cookie(settings.cookie.name));
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} else {
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pu_log("Not runatonce, but no cookie value", 2);
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reset_timer(timerInterval);
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}
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}).fail(function() {
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pu_log("Could not load the cookies handler script", 1);
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reset_timer(timerInterval);
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});
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} else {
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if($.cookie(settings.cookie.name)) {
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reset_timer($.cookie(settings.cookie.name));
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}
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}
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}
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// Construct the settings for $.ajax based on settings
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var ajaxSettings = jQuery.extend(true, {}, settings);
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if (settings.type && !ajaxSettings.dataType) { ajaxSettings.dataType = settings.type; }
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if (settings.sendData) { ajaxSettings.data = settings.sendData; }
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ajaxSettings.type = settings.method; // 'type' is used internally for jQuery. Who knew?
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ajaxSettings.ifModified = true;
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// Create the function to get data
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function getdata(force) {
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var toSend = jQuery.extend(true, {}, ajaxSettings); // jQuery screws with what you pass in
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if (typeof (options.data) == 'function') {
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toSend.data = options.data();
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}
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if (toSend.data) {
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// Handle transformations (only strings and objects are understood)
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if (typeof (toSend.data) == "number") {
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toSend.data = toSend.data.toString();
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}
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}
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if (force || maxCalls === 0) {
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pu_log("Sending data");
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$(function() { $.ajax(toSend); });
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} else if (maxCalls > 0 && calls < maxCalls) {
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pu_log("Sending data because we are at " + calls + " of " + maxCalls + " calls");
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$(function() { $.ajax(toSend); });
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calls++;
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} else if(maxCalls == -1) {
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pu_log("NOT sending data: stop has been called", 1);
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} else {
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pu_log("NOT sending data: maximum number of calls reached - " + maxCalls, 1);
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}
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}
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var handle = {
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boostTimer: function(mag) {
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if(mag > 0 && mag != 1) {
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pu_log("Boosting timer by a factor of " + mag);
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timerInterval = timerInterval * mag;
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} else {
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pu_log("Cannot boost timer by a factor of " + mag);
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}
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reset_timer(timerInterval);
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return;
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},
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restart: function (newInterval) {
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pu_log("Calling restart");
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maxCalls = originalMaxCalls;
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calls = 0;
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noChange = 0;
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reset_timer(newInterval || timerInterval);
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return;
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},
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send: function() {
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pu_log("Explicit call to send");
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getdata(true);
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return;
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},
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stop: function () {
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pu_log("Calling stop");
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maxCalls = -1;
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if(settings.cookie && $.cookie) {
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$.cookie(settings.cookie.name, null, settings.cookie);
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}
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return;
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}
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};
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// Implement the tricky comparison logic
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ajaxSettings.success = function (data) {
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pu_log("Successful run! (In 'success')", 2);
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remoteData = data;
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};
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ajaxSettings.complete = function (xhr, success) {
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pu_log("Status of call: " + success + " (In 'complete')", 2);
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if (success == "success" || success == "notmodified") {
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var rawData = $.trim(xhr.responseText);
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if (prevData == rawData) {
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if (autoStop > 0) {
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noChange++;
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if (noChange == autoStop) {
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handle.stop();
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if (settings.autoStopCallback) { settings.autoStopCallback(noChange); }
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return;
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}
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}
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boostPeriod();
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} else {
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noChange = 0;
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reset_timer(settings.minTimeout);
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prevData = rawData;
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if (settings.cookie) $.cookie(settings.cookie.name, prevData, settings.cookie);
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if (remoteData === null) { remoteData = rawData; }
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// jQuery 1.4+ $.ajax() automatically converts "data" into a JS Object for "type:json" requests now
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// For compatibility with 1.4+ and pre1.4 jQuery only try to parse actual strings, skip when remoteData is already an Object
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if ((ajaxSettings.dataType === 'json') && (typeof (remoteData) === 'string') && (success == "success")) {
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remoteData = JSON.parse(remoteData);
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}
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if (settings.success) { settings.success(remoteData, success, xhr, handle); }
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if (callback) { callback(remoteData, success, xhr, handle); }
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}
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}
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if (settings.complete) { settings.complete(xhr, success); }
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remoteData = null;
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};
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ajaxSettings.error = function (xhr, textStatus) {
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pu_log("Error message: " + textStatus + " (In 'error')", 2);
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if(textStatus != "notmodified") {
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prevData = null;
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if(settings.cookie) $.cookie(settings.cookie.name, null, settings.cookie);
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reset_timer(settings.minTimeout);
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}
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if(settings.error) { settings.error(xhr, textStatus); }
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};
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// Make the first call
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if (settings.runatonce) {
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pu_log("Executing a call immediately", 1);
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getdata(true);
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} else if($.cookie && $.cookie(settings.cookie.name)) {
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// Do nothing (already handled above)
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} else {
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pu_log("Enqueing a the call for after " + timerInterval, 1);
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reset_timer(timerInterval);
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}
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return handle;
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};
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// The bound version
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$.fn.PeriodicalUpdater = function(url, options, callback) {
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var me = this;
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return $.PeriodicalUpdater(url, options, function() {
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return callback.apply(me, arguments);
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});
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};
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})(jQuery);
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