Develop Reference

Loading GIF while AJAX completes

This should be quite simple but I'll be darned if I can work it out. Just trying to get a div to display while my ajax is processing and then hide once done (I've put a sleep in there purely to test its working as locally it loads so fast I'm not sure if its working or not)!
The html page has this code in the script: -
$(document).ready(function(){
$("#loadingGIF").ajaxStart(function () {
$(this).show();
});
$("#loadingGIF").ajaxStop(function () {
window.setTimeout(partB,5000)
$(this).hide();
});
function partB(){
//just because
}
var scenarioID = ${testScenarioInstance.id}
var myData = ${results as JSON}
populateFormData(myData, scenarioID);
});
There is then a div in my page like so (which I can see in the source of the page just hidden): -
<div id="loadingGIF" ><img src='${application.contextPath}/images/spinner.gif' height="50" width="50"></div>
The ready code then goes off and calls this: -
function populateFormData(results, scenarioID) {
$table = $('#formList')
for(var i in results){
var formIDX = (results[i]["forms_idx"])
var formID = (results[i]["form_id"])
appendSubTable(formIDX, scenarioID, $table, formID);
}
}
Which references this multiple times calling several AJAX posts: -
function appendSubTable(formIDX, scenarioID, $table, formID) {
var $subTable = $table.find("#" + formIDX).find('td:eq(1)').find("div").find("table")
var url = "**Trust me this bits OK ;) **"
$.post(url, {
formIDX : formIDX, scenarioID : scenarioID, formID :formID
}, function(data) {
$subTable.append(data)
}).fail(function() {
});
}
Any pointers gratefully received...
Interestingly I bunged some alerts into my ajaxstart and stop and neither show up ever so I'm missing something obvious :S When I check the console in firefox I can see that all my POSTs are completing....

You should probably add the Ajaxstart and stop global event handlers to the document node like this
$(document).ajaxStart(function () {
$("#loadingGIF").show();
});

I realized my problem, I needed to register the ajaxstart and stop to the document not the div!
So instead of this: -
$("#loadingGIF").ajaxStart(function () {
$(this).show();
});
I now have: -
$(document).ajaxStart(function () {
$("#loadingGIF").show();
});
I assume this is because its the document that the ajax is running against not the div although my understanding there may not be 100% accurate at least this works so please tell me if I've misunderstood this! :)
#jbl, thanks for this pointer I did this to also leave the notification on screen for a few more moments just to make sure everything is loaded.

how to delay call to JS function - animated gif not working in IE

I'm struggling to get an animated gif to run in IE. Works in all other browsers, but in IE it just freezes. I've researched this and looks like a delay using setTimeout might work. Not too sure how I add this to the following function:
<script type="text/javascript">
$(function(){
$('#photo_form').on("submit", function () {
$('#loading').show();
});
});
</script>
The gif is inside a div called 'loading' which is hidden. Would I add the timeout to onClick of the button or within the function itself?
Why does IE make things so difficult!?
Any help with solving this problem would be very helpful.

You mean something like this?
$(function() {
$('#photo_form').on("submit", function () {
setTimeout(function () {
$('#loading').show();
}, 100);
});
});

Try this curde, untested psedo-code:
var startTime;
var thread;
$(function(){
$('#photo_form').on("submit", function () {
$('#loading').show();
startTime = time();
thread = setInterval("showLoadingGif", 1);
});
function showLoadingGif() {
var timeToWait = 5; //change interval as needed
if(timeToWait + startTime <= currentTime) {
//show the gif
clearInterval(thread);
}
}
It's been a long time since I've worked with javascript, so this almost certainly needs adjustment; but the principle is the same: keep calling that function, and let that function decide when to stop being called.
setTimeout() will cause your page to freeze while you wait. setInterval will run your code asyncronously.

Same browser version, 2 different javascript handlings

Problem solved: I removed the first function as it wasn't needed anyways, and now it all works in all browsers. Thanks for the posts though!
My issue here is that I have a javascript which on one server runs perfectly with no issues what-so-ever in IE. But on another server gives me 2 errors in IE.
It claims that my offset().top is either Null or not an object.
My fade in and out effect doesn't even become active.
Then I have another HUGE issue, which is that in FireFox NON of it all works.
OPS: This is a webpart, so additional javascripts running on the site might could intervene with the javascript I am trying to execute here. But I'm not sure.
I've tested this webpart in IE 8.0.7600.16385, on both servers.
Script:
<script type="text/javascript"
src="/_layouts/Progressive/Javascripts/jquery-1.4.3.js"></script>
<script type="text/javascript">
(function($) {
$.fn.goTo = function() {
// This is where IE on the second server claims the error to be.
$('html, body').animate({scrollTop: $(this).offset().top + 'px'}, 'fast');
return this;
}
})(jQuery);
function showParagraphs(sender) {
var id = sender.getAttribute('href');
if ($('#<%=paragraph.ClientID%>').hasClass("readable")) {
$('#<%=paragraph.ClientID%>').removeClass("readable");
highlightSelected(id);
}
else {
$('#<%=paragraph.ClientID%>').addClass("readable");
rmvClass(id);
}
};
function highlightSelected(id) {
$(id).goTo();
$(id).addClass("reading");
// This part is what isn't activated on the second server.
$('.reading').fadeOut(400).fadeIn(400).fadeOut(400).fadeIn(400);
// .reading only adds a gray background to the DIV.
};
function rmvClass(id) {
$('div').each(function() {
if ($(this).hasClass("reading")) {
$(this).removeClass("reading");
}
});
}
function toTop() {
$('div').each(function() {
$(this).removeClass("reading");
});
$('#<%=paragraph.ClientID%>').addClass("readable");
}
$(document).ready(function() {
$('#<%=q.ClientID%>').find('dd').hide().end().find('dt').click(function() {
$(this).next().slideToggle("fast");
});
$("#<%=q.ClientID%> dt").click(function() {
if ($(this).hasClass("selected")) {
$(this).removeClass("selected");
}
else {
$(this).addClass("selected");
}
});
});
</script>
Any thoughts or suggestions?

When
$(id)
returns an empty jQuery object, then ".offset()" will return null. You're calling that "highlightSelected" code with the "href" value from something, so perhaps what you think to be an "id" value that corresponds to something on the page, well it really doesn't. It's hard to know for sure, however, because you did not post any of the relevant HTML, nor did you even show where "showParagraphs()" is called!

update a JQuery progress bar added at runtime

I'm having some problems updating a jquery progress bar. This progress bar isn't in the document during the page load, I'm adding it just when the user click on a button, ding something like this:
$(this).parent().append('<div class="progressbar"></div>');
$(this).parent().children('div.progressbar').show();
$(this).parent().children('div.progressbar').progressbar({value: 20});
then, using a timeout, I'm trying to update it
function updateProgressBar() {
$('.progressbar').each(function() {
myNewValue = getNewValue();
$(this).progressbar('value', 50);
});
setTimeout('updateProgressBar()', 5000);
}
setTimeout('updateProgressBar()', 5000);
the debug console complains saying: "Uncaught: cannot call methods on progressbar prior to initialiaztion: attempted to call method 'value'"
Googling here I found that the problem could be related to the inizialization of the progress bar after the loading of the page
Could someone help me?
Thanks in advance
-- edit --
thanks Bryan, I'm trying your solution but i doesn't work for me
Now I've this code
function startProgress() {
$(this).parent().append('<div class="progressbar"></div>');
$(this).siblings('.progressbar').show();
$(this).siblings('.progressbar').progressbar({value: 0});
function updateProgress() {
$('.progressbar').each(function() {
myNewValue = getNewValue($(this).parent().parent().attr('id'));
$(this).progressbar('value', myNewValue);
});
setTimeout('updateProgress', 5000);
}
setTimeout('updateProgress', 5000);
}
The console is sayng there's no updateProgress defined
-- edit --
many many thanks!!!
Now i've a quite definitive version that works...
Here my current code
if($(this).siblings('.progressbar').size() == 0) {
$(this).parent().append('<div class="progressbar"/>');
$(this).siblings('.progressbar').progressbar({value: 0});
}
$(this).siblings('.progressbar').show();
function updateProgress() {
$('.progressbar').each(function() {
myParams = 'service=' + $(this).parent().parent().attr('id') + '&content=' + $(this).parent().attr('id')
myUrl = '/datacast/content_progress/?' + myParams;
theValue = $(this).progressbar('value');
$.get(myUrl, {}, function(aReply) {
myData = aReply.split(' ');
myItemId = myData[0];
myValue = parseInt(myData[1]);
try {
$(".item[id = " + myItemId + "]").children(".progressbar").progressbar('value', myValue);
}
catch(myError) {
//alert(myError);
}
})
});
setTimeout(updateProgress, 5000);
}
setTimeout(updateProgress, 5000);
As you can see I've add a control if there is already a progress bar as i pass thorough that code several times.
The progress bar is updated every time, but the console complains saying "TypeError: Cannot call method 'apply' of undefined", so I had to add the try block with an empty catch body to drop the error. The page works but it could be interesting if you have an idea why there's that error

Had the same problem
Apparently you must use the format progressbar({value:30}) the first time
If you use progressbar(value,30) the first time then you get this exception.

Ok, I can't believe I missed that. The problem is that you're passing a string to the setTimeout function. This will cause it to lookup the name of the function in global scope, which it's not.
Change both of these calls:
setTimeout('updateProgress', 5000);
to
setTimeout(updateProgress, 5000);

Make sure that you're using the exact same selector in your update method as in the initialization method.
In the provided code, you're doing something like $(this).parent().children().find('.progressbar') and then in the update you're just doing $('.progressbar'). That second call could potentially return items that the first one didn't, and those items wouldn't have a progress bar initialized.
This code worked fine for me:
$(function(){
$('body').append('<div class="progress"></div>');
var val = 10;
$('.progress').progressbar({value:val});
function updateProgress() {
val += 10;
$('.progress').progressbar('value', val);
if(val < 100)
setTimeout(updateProgress, 1000);
}
setTimeout(updateProgress, 1000);
});
Also, remember that you don't actually need that call to each() as jquery methods should automatically apply to all elements matched with that selector.
Example:
$('.red').each(function(){ $(this).css({color:'red'}); });
is redundant, and the same can be achieved with:
$('.red').css({color:'red'});
Oh, and here's a freebie:
$(this).parent().children().find('.progressbar')
can be shortened to: $(this).siblings('.progressbar')

Get text from field on keyup, but with delay for further typing

I have a form which is submitted remotely when the various elements change. On a search field in particular I'm using a keyup to detect when the text in the field changes. The problem with this is that when someone types "chicken" then the form is submitted seven times, with only the last one counting.
What would be better is something like this
keyup detected - start waiting (for one second)
another keyup detected - restart waiting time
waiting finishes - get value and submit form
before I go off and code my own version of this (I'm really a backend guy with only a little js, I use jQuery for everything), is there already an existing solution to this? It seems like it would be a common requirement. A jQuery plugin maybe? If not, what's the simplest and best way to code this?
UPDATE - current code added for Dan (below)
Dan - this may be relevant. One of the jQuery plugins I'm using on the page (tablesorter) requires this file - "tablesorter/jquery-latest.js", which, if included, leads to the same error with your code as before:
jQuery("input#search").data("timeout", null) is undefined
http‍://192.168.0.234/javascripts/main.js?1264084467
Line 11
Maybe there's some sort of conflict between different jQuery definitions? (or something)
$(document).ready(function() {
//initiate the shadowbox player
// Shadowbox.init({
// players: ['html', 'iframe']
// });
});
jQuery(function(){
jQuery('input#search')
.data('timeout', null)
.keyup(function(){
jQuery(this).data('timeout', setTimeout(function(){
var mytext = jQuery('input#search').val();
submitQuizForm();
jQuery('input#search').next().html(mytext);
}, 2000)
)
.keydown(function(){
clearTimeout(jQuery(this).data('timeout'));
});
});
});
function submitQuizForm(){
form = jQuery("#searchQuizzes");
jQuery.ajax({
async:true,
data:jQuery.param(form.serializeArray()),
dataType:'script',
type:'get',
url:'/millionaire/millionaire_quizzes',
success: function(msg){
// $("#chooseQuizMainTable").trigger("update");
}
});
return true;
}

Sorry i haven't tested this and it's a bit off the top of my head, but something along these lines should hopefully do the trick. Change the 2000 to however many milliseconds you need between server posts
<input type="text" id="mytextbox" style="border: 1px solid" />
<span></span>
<script language="javascript" type="text/javascript">
jQuery(function(){
jQuery('#mytextbox')
.data('timeout', null)
.keyup(function(){
clearTimeout(jQuery(this).data('timeout'));
jQuery(this).data('timeout', setTimeout(submitQuizForm, 2000));
});
});
</script>

Here's your fancy jquery extension:
(function($){
$.widget("ui.onDelayedKeyup", {
_init : function() {
var self = this;
$(this.element).keyup(function() {
if(typeof(window['inputTimeout']) != "undefined"){
window.clearTimeout(inputTimeout);
}
var handler = self.options.handler;
window['inputTimeout'] = window.setTimeout(function() {
handler.call(self.element) }, self.options.delay);
});
},
options: {
handler: $.noop(),
delay: 500
}
});
})(jQuery);
Use it like so:
$("input.filterField").onDelayedKeyup({
handler: function() {
if ($.trim($(this).val()).length > 0) {
//reload my data store using the filter string.
}
}
});
Does a half-second delay by default.

As an update, i ended up with this which seems to work well:
function afterDelayedKeyup(selector, action, delay){
jQuery(selector).keyup(function(){
if(typeof(window['inputTimeout']) != "undefined"){
clearTimeout(inputTimeout);
}
inputTimeout = setTimeout(action, delay);
});
}
I then call this from the page in question's document.ready block with
afterDelayedKeyup('input#search',"submitQuizForm()",500)
What would be nice would be to make a new jquery event which uses this logic, eg .delayedKeyup to go alongside .keyup, so i could just say something like this for an individual page's document.ready block.
jQuery('input#search').delayedKeyup(function(){
submitQuizForm();
});
But, i don't know how to customise jquery in this way. That's a nice homework task though.

Nice job, Max, that was very helpful to me! I've made a slight improvement to your function by making it more general:
function afterDelayedEvent(eventtype, selector, action, delay) {
$(selector).bind(eventtype, function() {
if (typeof(window['inputTimeout']) != "undefined") {
clearTimeout(inputTimeout);
}
inputTimeout = setTimeout(action, delay);
});
}
This way you can use it for any type of event, although keyup is probably the most useful here.

I know this is old, but it was one of the first results when I was searching for how to do something like this so I though I would share my solution. I used a combination of the provided answers to get what I needed out of it.
I wanted a custom event that worked just like the existing jQuery events, and it needed to work with keypress + delete, backspace and enter.
Here's my jQuery plugin:
$.fn.typePause = function (dataObject, eventFunc)
{
if(typeof dataObject === 'function')
{
eventFunc = dataObject;
dataObject = {};
}
if(typeof dataObject.milliseconds === 'undefined')
dataObject.milliseconds = 500;
$(this).data('timeout', null)
.keypress(dataObject, function(e)
{
clearTimeout($(this).data('timeout'));
$(this).data('timeout', setTimeout($.proxy(eventFunc, this, e), dataObject.milliseconds));
})
.keyup(dataObject, function(e)
{
var code = (e.keyCode ? e.keyCode : e.which);
if(code == 8 || code == 46 || code == 13)
$(this).triggerHandler('keypress',dataObject);
});
}
I used $.proxy() to preserve the context in the event, though there could be a better way to do this, performance-wise.
To use this plugin, just do:
$('#myElement').typePause(function(e){ /* do stuff */ });
or
$('#myElement').typePause({milliseconds: 500, [other data to pass to event]},function(e){ /* do stuff */ });