I have 2 pages that require a function to be called every minute so I did this using setInterval(). However whenever I navigate to the page a new interval is created and it eventually bogs down the site. Is there a way to cancel an interval whenever I navigate away from a page?
var pollinginterval = 60000;
$('#HomeViewPage_MyLocation').live('pagebeforeshow', function(toPage, fromPage){
GetUsersByLocation();
setInterval(function() {
GetUsersByLocation();
}, pollinginterval);
});
$('#HomeViewPage_ColleagueLocation').live('pageshow', function(toPage, fromPage){
GetAllUsersByTeam();
GetAvailableTeams();
setInterval(function() {
GetAllUsersByTeam();
GetAvailableTeams();
}, pollinginterval);
});
Do you mean when refreshing the browser page? Then you can stop it by listenting for unload:
var runMyFunction = function() {
// clear interval
};
window.onunload = runMyFunction();
If not, you can still clear the interval on your internal page change.
This is because jQM has a problem with multiple events. Ok it is not a problem, you must understand, in your case, each time you access your page same event is applied again.
You can do 2 things to solve this problem:
Instead of live use bind/unbind and on/off to unbind event before binding it again to same element after each pagebeforeshow/pageshow. This is not that good approach.
Example for click event:
$('#elementID').unbind();
$('#elementID').bind('click', function(e) {
});
Correct one would be to use Event filter to check if event is already bound. It can be found here: http://www.codenothing.com/archives/2009/event-filter/
Example for click event:
$('#elementID:Event(click)').each(function(){
});
Related
I am trying to show the loading animation during a function call that takes some time. The function call is searching a large array that is already loaded. After the search, matching items are inserted into a table. The table is cleared prior to starting the search.
The problem is the animation only displays during the brief moment when the page updates.
Here is my code:
var interval = setInterval(function ()
{
$.mobile.loading('show');
clearInterval(interval);
}, 1);
DoSearch(term, function ()
{
var interval = setInterval(function ()
{
$.mobile.loading('hide');
clearInterval(interval);
}, 1000);
});
//The search function looks like this (detail omitted for brevity):
function DoSearch(term)
{
$("table#tableICD tbody").html('');
// also tried:
/*$("table#tableICD tbody")
.html('')
.table()
.closest("table#tableICD")
.table("refresh")
.trigger("create");*/
var tr = '';
$.each(codes, function (key, value)
{
// determine which items match and add them as table rows to 'tr'
});
$("table#tableICD tbody")
.append(tr)
.closest("table#tableICD")
.table("refresh")
.trigger("create");
callback();
}
The search works properly and adds the rows to the table. I have two unexpected behaviors:
The table does not clear until the search is complete. I have tried adding .table("refresh").trigger("create") to the line where I set the tbody html to an empty string. This does not help. (see commented line in the code)
As I mentioned, the animation displays briefly while the screen is refreshing. (Notice I set the interval to 1000 in the second setInterval function just so I could even see it.)
The suggestions I have read so far are to use setInterval instead of straight calling $.mobile.loading, which I have done and placing the search in a function and using a callback, which I have also done.
Any ideas?
Let me give you a few suggestions; they will probably not solve all your issues but they may help you found a solution.
jQuery Mobile is buggy, and for some features, we will never know were they intended to work like that or are they just plain bugs
You can call $.mobile.loading('show') on its own only in pageshow jQuery Mobile event. In any other case, you need to do it in interval or timeout.
It is better to do it in timeout, mostly because you are using less code. Here an example I made several years ago: http://jsfiddle.net/Gajotres/Zr7Gf/
$(document).on('pagebeforecreate', '[data-role="page"]', function(){
setTimeout(function(){
$.mobile.loading('show');
},1);
});
$(document).on('pageshow', '[data-role="page"]', function(){
// You do not need timeout for pageshow. I'm using it so you can see loader is actualy working
setTimeout(function(){
$.mobile.loading('hide');
},300);
});
It's difficult to enhance any jQuery Markup in real time after a page was loaded. So my advice is to first generate new table content, then clean it, and then update markup using .table("refresh").
Do table refresh only once, never do it several times in the row. It is very resourced heavy method and it will last a very long time if you run it for every row
If you are searching on keypress in the input box then showing it in the table; that is the least efficient method in jQuery Mobile. jQM is that slow, it is much better to use listview component which is least resource extensive.
I'm using jquery mobile v1.3.2
For some reasons I want to set an global pagechange event to prepare all of my pages :
var Front = {
initDom : function($dom) {
// here i can bind some events in my page
$(".someButton",$dom).bind("tap",function(){
alert("some actions");
});
// etc.....
});
}
$(document).on("pagechange", function(event, data) {
Front.initDom($(data.toPage));
});
This works well. But it is triggered at each page change. And some times it will init the same event twice and that will lead to some bugs.
Now i have tested to do it with the event pageinit or pagecreate but both are triggered before the page is ready and $("ui-page-active"); is empty.
I have though about some setTimeout, but that's definitively a bad idea.
I have also though to init everything at the first pageinit and unbind it. But ajax called page wont be bound.
It there some good workarround ?
You can use pageinit and then get the id of the page from the event target object:
$(document).on("pageinit", function(e){
alert(e.target.id);
});
DEMO
I fill list dynamically, and after that on click I have multiple calls of event. 1st time it is repeated 1 time, 2nd time 2 times, 3rd time 3 times, etc...
First, more about this problem can be found in my other answer: jQuery Mobile: document ready vs page events
Prevent multiple event binding/triggering
Because of interesting jQM loading architecture, multiple event triggering is a constant problem. For example, take a look at this code snipet:
$(document).on('pagebeforeshow','#index' ,function(e,data){
$(document).on('click', '#test-button',function(e) {
alert('Button click');
});
});
Working jsFiddle example: http://jsfiddle.net/Gajotres/CCfL4/
Each time you visit page #index click event will is going to be bound to button #test-button. There are few ways to prevent this problem:
Solution 1:
Remove event before you bind it:
$('#index').live('pagebeforeshow',function(e,data){
$('#test-button').die().live('click', function(e) {
alert('Button click');
});
});
Working jsFiddle example: http://jsfiddle.net/Gajotres/K8YmG/
In case you have different events bound to an object:
$('#index').live('pagebeforeshow',function(e,data){
$('#test-button').die('click').live('click', function(e) {
alert('Button click');
});
});
Solution 2:
Use a jQuery Filter selector, like this:
$('#carousel div:Event(!click)').each(function(){
//If click is not bind to #carousel div do something
});
Because event filter is not a part of official jQuery framework it can be found here: http://www.codenothing.com/archives/2009/event-filter/
In a nutshell, if speed is your main concern then Solution 2 is much better then Solution 1.
Solution 3:
A new one, probably an easiest of them all.
$(document).on('pagebeforeshow', '#index', function(){
$(document).on('click', '#test-button',function(e) {
if(e.handled !== true) // This will prevent event triggering more then once
{
alert('Clicked');
e.handled = true;
}
});
});
Working jsFiddle example: http://jsfiddle.net/Gajotres/Yerv9/
Tnx to the sholsinger for this solution: http://sholsinger.com/archive/2011/08/prevent-jquery-live-handlers-from-firing-multiple-times/
More info
If you want to find more about this problem take a look at this article, working examples are included.
I am using the pagecreate initialization event to call a function which makes an AJAX call to populate a list.
The problem I have is that this event never completes. The page loading message persists.
I've search here and on the Jquery forum, without any luck.
My code looks like this:
$( "#events" ).live( 'pagecreate', function(event) {
// Executed once the page is loaded
var fromDate = new Date(),
toDate = new Date(fromDate.getFullYear(), fromDate.getMonth() + 3, fromDate.getDate());
update(fromDate, toDate);
//alert('done');
});
function update(from, to) {
var eventList = $('ul#event-list');
$.ajax({
url: 'events.php',
dataType: 'json',
data: {from: from, to: to},
success: function(data) {
showEvents(data, from, to, eventList); // Create list items and append to eventList
$('.value h2').formatCurrency({ negativeFormat: "-%s%n" }); // Format currency correctly using jQuery plugin
}
});
}
I get an "a.Deferred is not a function" error, which suggests to me it has something to do with the completion of the AJAX call, but I've checked, and the showEvents function is correctly creating the list items, so it's not hanging.
After reading this, I tried alternative initialization events: pageinit, and even changePage, without success.
Thanks for your help.
p.s. in case it helps, uncommenting that alert() gets the updated list to reformat correctly, without solving the problem. I figure I'd mention it, since I obviously don't understand what's going on.
If u want to run
the code only once when your project loaded then use
mobileinit. pageshow for every view of page and pagecreate for first
time when pagecreate in your project.
I have a JQuery Mobile Multi-Page layout and I want to trigger a function when a select menu on my site is changed.
Currently when the menu is changed three events fire.
I have put together an example that should show you what i'm facing.
From the main menu click Web Settings
Change the Theme option on the page
Notice the three alerts
Here is my code to register the event
$(document).bind("pagecreate", function() {
$("#settings-theme").bind("change", function(event) {
alert(event.target);
});
});
Things I have tried:
Changing the data-native-menu="false" to true removed one of the event firings.
Removed all other pages except web settings and that also reduced the number of events firing to two.
In JSFiddle, Framework Options > Head (nowrap) changed to DomReady also removed a event fire.
Update
It appears that pagecreate is fired every time a page is 'first-viewed' as well as twice when the homepage is loaded.
So by the time the settings page is loaded the event has been binded three times.. still no solution.
$(document).bind("ready", function() {
$("#settings-theme").live("change", function() {
alert("changed");
});
});
or
$(document).bind("ready", function() {
$("#pg-settings").delegate("#settings-theme", "change", function() {
alert("changed");
});
});