I have some jQuery that is triggered on click of a link with the class 'changetag'
. I'm using $.ajax()
to update the database via changetag.php.
I then change the visual appearance of the link by toggling the class between on/off. The code is as follows:
$(function() {
$(".changetag").click(function(){
var element = $(this);
var I = element.attr("id");
var info = 'switch_tag=' + I;
$.ajax({
type: "POST",
url: "_js/changetag.php",
data: info,
success: function(){}
});
$("#li_"+I).toggleClass("off on");
element.toggleClass("off on");
return false;
});
});
Works perfectly. But now I want to add in a second PHP call which will pull data and update another area of the page if the above was successful.
What I'm trying to add is:
$.ajax({
url: "_js/loaddata.php",
success: function(results){
$('#listresults').empty();
$('#listresults').append(results);
}
});
But just adding it into success: function(){} doesn't seem to be working. To clarify, here is the complete code I'm testing:
$(function() {
$.ajaxSetup ({cache: false});
$(".changetag").click(function(){
var element = $(this);
var I = element.attr("id");
var info = 'switch_tag=' + I;
$.ajax({
type: "POST",
url: "_js/changetag.php",
data: info,
success: function(){
$.ajax({
url: "_js/loaddata.php",
success: function(results){
$('#listresults').empty();
$('#listresults').append(results);
}
});
}
});
$("#li_"+I).toggleClass("off on");
element.toggleClass("off on");
return false;
});
});
The PHP scripts are both called successfully and the toggle class works, but the data pulled is not written to #listresults for some reason.
Ajax calls are (by default) asynchronous . That means that this code:
$("#li_"+I).toggleClass("off on");
element.toggleClass("off on");
return false;
could be executed before the ajax call preceding it is finished. This is a common problem for programmers who are new to ajax and asynchronous code execution. Anything you want to be executed after the ajax call is done must be put into a callback , such as your success
handler:
$.ajax({
type: "POST",
url: "_js/changetag.php",
data: info,
success: function(){
$("#li_"+I).toggleClass("off on");
element.toggleClass("off on");
}
});
Likewise, you could put the second ajax call in there as well:
$.ajax({
type: "POST",
url: "_js/changetag.php",
data: info,
success: function(){
$("#li_"+I).toggleClass("off on");
element.toggleClass("off on");
$.ajax({
url: "_js/loaddeals_v2.php",
success: function(results){
$('#listresults').empty();
$('#listresults').append(results);
}
});
}
});
With jQuery 1.5's Deferred Object , you can make this slicker.
function firstAjax() {
return $.ajax({
type: "POST",
url: "_js/changetag.php",
data: info,
success: function(){
$("#li_"+I).toggleClass("off on");
element.toggleClass("off on");
}
});
}
// you can simplify this second call and just use $.get()
function secondAjax() {
return $.get("_js/loaddata.php", function(results){
$('#listresults').html(results);
});
}
// do the actual ajax calls
firstAjax().success(secondAjax);
This is nice because it lets you un-nest callbacks - you can write code that executes asynchronously, but is written like synchronously-executed code.
Deprecation Notice : The jqXHR.success(), jqXHR.error(), and jqXHR.complete() callbacks are removed as of jQuery 3.0. You can use jqXHR.done(), jqXHR.fail(), and jqXHR.always() instead. https://api.jquery.com/jQuery.ajax/#jqXHR
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