Develop Reference

jQuery synchronous call

For rendering a dialog, i have two jQuery ajax calls. One to load the buttons and another to load the body of the dialog. I first call the function that loads the buttons (asychronous ajax call)
$.ajax({
type: "POST",
//async: false,
url: action,
dataType: "json",
contentType: "application/json; charset=utf-8",
success: function (result) {
$('#dialogButtons').html(result);
},
error: function (req, status, error) {
alert(req + " " + error + " " + status);
}
Then i call another similar ajax call to load the body of the dialog in asychronous fashion.
The buttons doesn't always show up. So I made
$.ajaxSetup({ async: false });
$.ajax({
asyc: false,
url: action
})
$.ajaxSetup({ async: true });
as per other stack overflow experts. i am seeing mixed opinions on this approach.
Please help me with the standard way to achieve this.

Do the second AJAX call in the success function of the first.
$.ajax({
type: "POST",
url: action,
dataType: "html",
success: function(result) {
$('#dialogButtons').html(result).hide(); // Will show it after 2nd AJAX call
$.ajax({
type: "POST",
dataType: "html",
url: otheraction,
success: function(result) {
if (result) {
$("#dialog").html(result);
$("#dialogButtons").show();
}
}
});
},
error: function(req, status, error) {
alert(req + " " + error + " " + status);
}
});
You also shouldn't have contentType: "application/json". You're not sending any post data, and $.ajax doesn't send JSON; if you had post data, it would be URL-encoded.

how can I authenticate to a rest web service by ajax

I want to send username and password to a Rest web service to recover the Token. I tested this code but always sends me to error function
$.ajax({
type: "POST",
url: "http://192.168.1.89:1111/connect/token",
dataType: 'json',
async: false,
data: '{}',
beforeSend: function(xhr) {
xhr.setRequestHeader('Authorization', btoa(username, password));
},
success: function() {
alert('Thanks for your comment!');
},
error: function(xhr, status, error) {
alert(error);
}
});

Jquery - ajax beforeSend basic authentication not working as expected

I am trying to send a request using ajax to a server which is protected by basic authentication with the following code:
$('document').ready(function(){
$.ajax({
url: "https://somesite.com/somefolder",
type: "POST",
dataType: 'jsonp',
beforeSend: function(xhr) {
xhr.setRequestHeader ("Authorization", "Basic " + btoa('myusername' + ":" + 'mypassword'));
},
success: function(data){
console.log('SUCCESS!');
},
error: function () {
console.log("error");
}
});
});
So I provide the credentials in the beforeSend so my expectation would be that there would be no credential popup from the browser since I already provided the credentials but unfortunately when i run this code I get the popup to enter my credentials. I want to the code to provide these credentials.

Similar to this question, example using headers:
$.ajax({
url: "https://somesite.com/somefolder",
type: "POST",
dataType: 'jsonp',
headers: {"Authorization": "Basic " + btoa('myusername' + ":" + 'mypassword')},
success: function(data){
console.log('SUCCESS!');
},
error: function () {
console.log("error");
}
});

How to show progress bar when calling AJAX?

I am developing a mobile app using phonegap (JQ + Html ). In my app, consuming REST webservice using AJAX calls.When service invoke, I am showing a progress bar animated GIF image . The problem is, browser freezes when calling AJAX. So the progress bar is not showing.
In ‘beforeSend’ i am showing the progress bar image and after ‘complete’ i am hiding the progress bar image.
I am also trying async: true . But it execute service as asynchronously. In my app, asynchronous execution is not suit. Because asynchronous execution will not wait for ajax executing. My app should wait until the ajax execution complete. In that process time I want show progress bar.
Here is my code.
$.ajax({
type: "POST",
dataType: "json",
contentType: "application/json",
accepts: "application/json",
beforeSend: function() {
StartPBar():
},
data: JSON.stringify(RQ),
async: false,
url: URL,
complete: function() {
stopPBar();
},
success: function(res, status, xhr) {
try {
RS = res;
} catch (e) {
alert(e);
}
},
error: function(XMLHttpRequest, textStatus, errorThrown) {
alert("Excpetion " + errorThrown + XMLHttpRequest);
}
});
Any suggestion to show the progress bar stay on screen until the process is fully complete? Any help would be appreciated. Thanks

Make sure you verify your javascript code.
Remove this code.
beforeSend: function() {
StartPBar():
},
Replace your jquery mobile with this one jQuery Mobile 1.4.0-rc.1
http://code.jquery.com/mobile/1.4.0/jquery.mobile-1.4.0.js
Replace your code with this one.
$.mobile.loading('show');
$.ajax({
type: "POST",
dataType: "json",
contentType: "application/json",
accepts: "application/json",
data: JSON.stringify(RQ),
async: false,
url: URL,
complete: function() {
$.mobile.loading('hide');
},
success: function(res, status, xhr) {
try {
$.mobile.loading('hide');
RS = res;
} catch (e) {
alert(e);
}
},
error: function(XMLHttpRequest, textStatus, errorThrown) {
$.mobile.loading('hide');
alert("Excpetion " + errorThrown + XMLHttpRequest);
}
});

Try to set async: true, the async: false will freeze the browser until the request is completed. Also move the async: true before beforeSend method.
The async: true, when supported by browser, basically means: browser will send data asynchronous and will not block or wait other actions from executing. This is the only in my opinion way to show the progress bar indicator. Because (from the documentation):
Note that synchronous requests may temporarily lock the browser,
disabling any actions while the request is active.

If you want to wait until ajax requests done, you can do it also with async:true like;
StartPBar():
$.when(runAjax()).done(function(result) {
// result conatins responseText, status, and jqXHR
stopPBar();
});
function runAjax() {
return $.ajax({
type: "POST",
dataType: "json",
contentType: "application/json",
accepts: "application/json",
data: JSON.stringify(RQ),
async: true,
url: URL,
success: function (res, status, xhr) {
try {
RS = res;
}
catch (e) {
alert(e);
}
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert("Excpetion " + errorThrown + XMLHttpRequest);
}
});
}
In this example, when ajax request completed, progressbar stop function will be called.

Jquery jsonp response error - Callback was not called

I'm trying to get some information from a different domain, the domain allows only jsonp call - others get rejected. How can I get the content instead of execution? Because I get an error in response. I don't need to execute it, I just need it in my script. In any format (the response is json but js doesn't understand it).
I can't affect on that domain so it's impossible to change something on that side.
Here's my code:
$.ajax({
url: url + '?callback=?',
crossDomain: true,
type: "POST",
data: {key: key},
contentType: "application/json; charset=utf-8;",
async: false,
dataType: 'jsonp',
jsonp: 'callback',
jsonpCallback: 'jsonpCallback',
error: function(xhr, status, error) {
console.log(status + '; ' + error);
}
});
window.jsonpCallback = function(response) {
console.log('callback success');
};

There are a few issues with your $.ajax call.
$.ajax({
url: url + '?callback=?',
// this is not needed for JSONP. What this does, is force a local
// AJAX call to accessed as if it were cross domain
crossDomain: true,
// JSONP can only be GET
type: "POST",
data: {key: key},
// contentType is for the request body, it is incorrect here
contentType: "application/json; charset=utf-8;",
// This does not work with JSONP, nor should you be using it anyway.
// It will lock up the browser
async: false,
dataType: 'jsonp',
// This changes the parameter that jQuery will add to the URL
jsonp: 'callback',
// This overrides the callback value that jQuery will add to the URL
// useful to help with caching
// or if the URL has a hard-coded callback (you need to set jsonp: false)
jsonpCallback: 'jsonpCallback',
error: function(xhr, status, error) {
console.log(status + '; ' + error);
}
});
You should be calling your url like this:
$.ajax({
url: url,
data: {key: key},
dataType: 'jsonp',
success: function(response) {
console.log('callback success');
},
error: function(xhr, status, error) {
console.log(status + '; ' + error);
}
});
JSONP is not JSON. JSONP is actually just adding a script tag to your <head>. The response needs to be a JavaScript file containing a function call with the JSON data as a parameter.
JSONP is something the server needs to support. If the server doesn't respond correctly, you can't use JSONP.
Please read the docs: http://api.jquery.com/jquery.ajax/

var url = "https://status.github.com/api/status.json?callback=apiStatus";
$.ajax({
url: url,
dataType: 'jsonp',
jsonpCallback: 'apiStatus',
success: function (response) {
console.log('callback success: ', response);
},
error: function (xhr, status, error) {
console.log(status + '; ' + error);
}
});
Try this code.
Also try calling this url directly in ur browser and see what it exactly returns, by this way You can understand better what actually happens :).

The jsonpCallback parameter is used for specifying the name of the function in the JSONP response, not the name of the function in your code. You can likely remove this; jQuery will handle this automatically on your behalf.
Instead, you're looking for the success parameter (to retrieve the response data). For example:
$.ajax({
url: url,
crossDomain: true,
type: "POST",
data: {key: key},
contentType: "application/json; charset=utf-8;",
async: false,
dataType: 'jsonp',
success: function(data){
console.log('callback success');
console.log(data);
}
error: function(xhr, status, error) {
console.log(status + '; ' + error);
}
});
You can also likely remove the other JSONP-releated parameters, which were set to jQuery defaults. See jQuery.ajax for more information.