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How to pass a variable from ajax to nested ajax

I'm sending ajax call and getting an answer that I need from the first ajax then I want to pass my result to my nested ajax, my var (result) is null in the nested ajax/settimeout fun, can I pass it ? Am I missing something ?
$.ajax({
url: '#Url.Action("getCustomerGuidId", "Document")',
type: 'POST',
cache: false,
data: { "classNum": currentclassNum},
contentType:'json' ,
dataType:'text',
success: function (result) {
alert(result);**-> is fine - not null**.
// a or result is null when I hit the getCurrentDoc- function althought I get the data I need from getCustomerGuidId function
var a = result;-> tried to pass it to a new var..IDK.. I
thought it will help... it didn't.
setTimeout(function () {
$.ajax({
type: "GET",
url: '#Url.Action("getCurrentDoc", "Document")',
contentType:'text',
data: a,-> here it's null
success: function (data) {
}
});
}, 2000);
},
error: function (result) {
alert("fail " + result);
}
});

You can try something like this will help to pass value to nested ajax call
function test(){
var myText = 'Hello all !!';
$.get({
//used the jsonplaceholder url for testing
'url':'https://jsonplaceholder.typicode.com/posts/1',
'method':'GET',
success: function (data) {
//updating value of myText
myText = 'welcome';
$.post({
'url':'https://jsonplaceholder.typicode.com/posts',
'method':'POST',
//data.title is the return value from get request to the post request
'data':{'title':data.title},
'success':function (data) {
alert(data.title +'\n' + myText);//your code here ...
}
});
}
});
}

An old question and you've likely moved on, but there's still no accepted answer.
Your setTimeout takes an anonymous function, so you are losing your binding; if you have to use a Timeout for some reason, you need to add .bind(this) to your setTimeout call (see below)
setTimeout(function () {
$.ajax({
type: "GET",
url: '#Url.Action("getCurrentDoc", "Document")',
contentType:'text',
data: a,
success: function (data) {
}
});
}.bind(this), 2000);
At a guess you're using a Timeout because you want to ensure that your promise (i.e. the first ajax call) is resolving prior to making the nested call.
If that's your intention, you can actually scrap setTimeout completely as you have the nested call in the first ajax success call, which only runs once the promise has been resolved (providing there isn't an error; if so, jQuery would call error rather than success)
Removing setTimeout means you won't lose your binding, and a should still be result (hopefully a is an object, otherwise your second call is also going to experience issues...)
Lastly, after overcoming the binding issue you wouldn't need var a = result; you should be able to pass result directly to your nested ajax call.
Good luck!

In the nested ajax you send a as a param name, not as a param value.
So you can try the following (change param to actual param name which your server expects):
$.ajax({
url: '#Url.Action("getCustomerGuidId", "Document")',
type: 'POST',
cache: false,
data: { "classNum": currentclassNum},
dataType:'text',
success: function (result) {
setTimeout(function () {
$.ajax({
type: "GET",
url: '#Url.Action("getCurrentDoc", "Document")',
data: {param: result},
success: function (data) {
}
});
}, 2000);
},
error: function (result) {
alert("fail " + result);
}
});

Callback Issue in JavaScript

I am trying to execute a WCF service call, from function one(). Only once this is complete I want function two() to be executed. The issue I have is that function two() is invoked before function one() completes execution and the WCF service returns the result. How can I solve this please? I am using callback function, so I can't figure out why, given that the response does not exceed 3 seconds.
<script type="text/javascript">
var jsonGetFileResult = "";
function one(callback) {
setTimeout(function() {
//var jsonGetFileResult = "";
console.log('01: into one');
$.ajax({
type: 'GET',
url: ‘http: //wcf.google.com’, //this is the wcf call
contentType: "application/json; charset=utf-8",
dataType: 'json',
data: {},
timeout: 10000,
success: function(data) {
jsonGetFileResult = stringifyNewsletter(data);
console.log('03: ' + jsonGetFileResult);
},
error: function(data) {
alert(error);
}
});
callback();
}, 3000);
}
function stringifyNewsletter(data) {
var removeHeader = JSON.stringify(data);
var file = removeHeader.split('"');
console.log('02: ' + file[3]);
return file[3];
}
function two(linkToNewsletter) {
window.open(linkToNewsletter, '_blank', 'location=yes');
return false;
}
/* now we make use of the callback */
one(function() {
alert(jsonGetFileResult);
// "one" triggers "two" as soon as it is done, note how "two" is a parameter
two(jsonGetFileResult);
});
</script>

You're invoking the callback outside of the ajax "success" function. The $.ajax() call is asynchronous — the call will return to your code essentially immediately, after launching the HTTP request and without waiting for it to finish.
If you move the line
callback();
to inside the "success" handler, then that will run after the HTTP request completes.

You need to put callback inside success function like that:
function one(callback) {
setTimeout(function() {
//var jsonGetFileResult = "";
console.log('01: into one');
$.ajax({
type: 'GET',
url: ‘http: //wcf.google.com’, //this is the wcf call
contentType: "application/json; charset=utf-8",
dataType: 'json',
data: {},
timeout: 10000,
success: function(data) {
jsonGetFileResult = stringifyNewsletter(data);
console.log('03: ' + jsonGetFileResult);
callback();
},
error: function(data) {
alert(error);
}
});
}, 3000);
}

Two Ajax onclick events

So I have had to modify some old existing code and add another ajax event to onclick
so that it has onclick="function1(); function2();"
This was working fine on our testing environment as it is a slow VM but on our live environment it causes some issues as function1() has to finished updating some records before function2() gets called.
Is there a good way to solve this without modifying the js for function2() as this the existing code which is called by other events.
Thanks

Call function2 upon returning from function1:
function function1() {
$.ajax({
type: "POST",
url: "urlGoesHere",
data: " ",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (result) {
//call function2
},
error:
});
}
Or wrap them in a function that calls both 1 and 2.

You need to use always callback of ajax method, check out always callback of $.ajax() method http://api.jquery.com/jquery.ajax/.
The callback given to opiton is executed when the ajax request finishes. Here is a suggestion :
function function1() {
var jqxhr = $.ajax({
type: "POST",
url: "/some/page",
data: " ",
dataType: "dataType",
}).always(function (jqXHR, textStatus) {
if (textStatus == 'success') {
function2();
} else {
errorCallback(jqXHR);
}
});
}

I'm assuming you use Prototype JS and AJAX because of your tags. You should use a callback function:
function function1(callback) {
new Ajax.Request('http://www.google.nl', {
onSuccess: function(response) {
callback();
}
});
}
function function2(callback) {
new Ajax.Request('http://www.google.nl', {
onSuccess: function(response) {
callback();
}
});
}
function both() {
function1(function() {
function2();
});
}
Then use onclick="both();" on your html element.
Example: http://jsfiddle.net/EzU4p/

Ajax has async property which can be set false. This way, you can wait for that function to complete it's call and set some value. It actually defeats the purpose of AJAX but it may save your day.
I recently had similar issues and somehow calling function2 after completing function1 worked perfectly. My initial efforts to call function2 on function1 success didn't work.
$.ajax({
type: "POST",
url: "default.aspx/function1",
data: "",
contentType: "application/json; charset=utf-8",
dataType: "json",
async: false, // to make function Sync
success: function (msg) {
var $data = msg.d;
if ($data == 1)
{
isSuccess = 'yes'
}
},
error: function () {
alert('Error in function1');
}
});
// END OF AJAX
if (isSuccess == 'yes') {
// Call function 2
}

Show a loading bar using jQuery while making multiple AJAX request

I have function making multiple AJAX request with jQuery like:
function() {
$.ajax({
url: "/url",
data: {
params: json_params,
output: 'json'
},
async: false,
success: function(res) {
data1 = res
}
});
$.ajax({
url: "/url",
data: {
params: json_params,
output: 'json'
},
async: false,
success: function(res) {
data2 = res;
}
return data1 + data2;
});
}
While this function is running and data is loading I want to display a loading image without blocking it.
I have tried showing the loading icon using ajaxSend ajaxComplete, but does not work, since I have multiple ajax calls.
I also tried showing the loading at the beginning of the function and hiding at the end of the function, but failed.
How to do this?

How exactly did you try loading? Using the ajaxStart/ajaxStop events on the elements is one way to accomplish what you want. It could look like this:
$('#loadingContainer')
.hide() // at first, just hide it
.ajaxStart(function() {
$(this).show();
})
.ajaxStop(function() {
$(this).hide();
})
;
Maybe this helps you, I often used this before and it works like a charm..

I think the answer is really a combination of several of these. I would begin with ajax start to show the loading image at 0 (or whereever you want the start to be). Then I would use a callback function to increment the loading bar and repaint it.
For example
//when ajax starts, show loading div
$('#loading').hide().on('ajaxStart', function(){
$(this).show();
});
//when ajax ends, hide div
$('#loading').on('ajaxEnd', function(){
$(this).hide();
});
function ajax_increment(value) {
//this is a function for incrementing the loading bar
$('#loading bar').css('width', value);
}
//do ajax request
$.ajax({
url:"", //url here
data: {params:json_params,output:'json'},
async: false,
success: function (res) {
data1=res
ajax_increment(20); //increment the loading bar width by 20
}
});
$.ajax({
url:"", //url here
data: {params:json_params,output:'json'},
async: false,
success: function (res) {
data1=res
ajax_increment($('loading bar').css('width') + 10); // a little more dynamic than above, just adds 10 to the current width of the bar.
}
});

You could try something like this: Define a callback with a counter, and the callback hides the image after it's been called the required number of times.
showLoadingImage();
var callbackCount = 0;
function ajaxCallback() {
++callbackCount;
if(callbackCount >= 2) {
hideImage();
}
}
$.ajax({
url:"/url",
data: {params:json_params,output:'json'},
async: false,
success: function (res) {
data1=res
ajaxCallback();
}
});
$.ajax({
url:"/url",
data: {params:json_params,output:'json'},
async: false,
success: function (res) {
data2=res;
ajaxCallback();
}
});
That's only necessary for asynchronous calls, though. The way you're doing it (all your AJAX calls are synchronous), you should be able to just call hideImage() before returning at the end of your outer function.

You should be able to bind to the start and then end with the following:
$('#loading-image').bind('ajaxStart', function() {
$(this).show();
}).bind('ajaxStop', function() {
$(this).hide();
});
Or you could use beforeSend and on Complete
$.ajax({
url: uri,
cache: false,
beforeSend: function() {
$('#image').show();
},
complete: function() {
$('#image').hide();
},
success: function(html) {
$('.info').append(html);
}
});

Deferred calls for multiple ajax calls

I have the following JS methods:
var foo = function() {
var dfd = $.Deferred();
console.log('foo');
dfd.resolve();
return dfd.promise();
};
var ajaxCall1 = function () {
var dfd = $.Deferred();
$.ajax({
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: 'json',
url: 'xxxxxxx',
data: { },
success: function(response) {
dfd.resolve();
}
});
return dfd.promise();
};
var ajaxCall2 = function () {
var dfd = $.Deferred();
$.ajax({
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: 'json',
url: 'xxxxxxx',
data: {},
success: function (response) {
dfd.resolve();
}
});
return dfd.promise();
};
var ajaxCall3 = function () {
var dfd = $.Deferred();
$.ajax({
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: 'json',
url: 'xxxxxxx',
data: {},
success: function (response) {
dfd.resolve();
}
});
return dfd.promise();
};
and I am calling them via this code:
foo().done(function () {
return ajaxCall1();
}).done(function () {
return ajaxCall2();
}).done(function () {
return ajaxCall3();
});
The issue is that ajaxCall2 is called before the success of ajaxcall1 has occurred. Can you help me fixing this? I need to make ajax calls one by one when success of previous one has occurred.

Use the $.when
var deferredObject = $.ajax({});
$.when(deferredObject)
.then(function(){
var deferredobject2 = $.ajax({});
$.when(deferredobject2)
.then(function(){ alert('after 2nd ajax call');});
});

First of all, you can return the results of the $.ajax calls directly since they are promises already (no need for an intermediate Deferred):
var ajaxCall1 = function () {
return $.ajax({
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: 'json',
url: 'xxxxxxx',
data: { }
});
};
var ajaxCall2 = function () {
return $.ajax({
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: 'json',
url: 'xxxxxxx',
data: {}
});
};
var ajaxCall3 = function () {
return $.ajax({
type: 'POST',
contentType: 'application/json; charset=utf-8',
dataType: 'json',
url: 'xxxxxxx',
data: {}
});
};
Second, what you wanna use is .pipe() to effectively chain the calls:
foo().pipe(function () {
return ajaxCall1();
}).pipe(function () {
return ajaxCall2();
}).pipe(function () {
return ajaxCall3();
}).done(function() {
// call1, call2 and call3 done in sequence
}).fail(function() {
// one of the ajax requests failed
});

Simplify.
function foo() {
var dfd = $.Deferred();
console.log('foo');
dfd.resolve();
return dfd.promise();
}
function ajaxCall1() {
return $.ajax({
type: 'POST',
dataType: 'json',
url: 'xxxxxxx',
data: { },
success: function(response) {
console.log('ajaxCall1 success');
}
});
return dfd.promise();
}
// and so on for ajaxCall2 and ajaxCall3
Enhance.
foo().done(function () {
ajaxCall1().done(function () {
ajaxCall2().done(function () {
ajaxCall3();
});
});
});
http://jsfiddle.net/mattball/LxjDS/
Further reading:
How to chain ajax calls using jquery
jQuery Deferred not calling the resolve/done callbacks in order
jQuery deferred - do I need pipes or chains to achieve this pattern?

Same as the other answer except simplifying the callbacks with Frame.js
var responses = [];
for(var i=0; i<1000; i++){
Frame(function(callback){
$.ajax('myserver.api', {
data:i,
type:'post',
complete:function(response) {
responses.push(response);
callback();
}
});
});
}
Frame.start();
Normally, slamming the browser with AJAX requests like this would cause the browser to hang, and the response variables would be returned in the order they are received, rather than the original order they were sent in. Adding Frame to the mix here sorts all that out.
Or you could just use it to flatten out the callbacks:
Frame(function(next){
foo().done(next);
});
Frame(function(next){
ajaxCall1().done(next);
});
Frame(function(next){
ajaxCall2().done(next);
});
Frame(function(next){
ajaxCall3().done(next);
});
Frame(function(next){
//do more stuff
next();
});
Frame.start();

I've had similar problems working heavily with SharePoint web services - you often need to pull data from multiple sources before you're able to continue working.
To solve it I embedded this kind of functionality into my AJAX abstraction library. You can easily define a request which will trigger a set of handlers when complete. However each request can be defined with multiple http calls. Here's the component:
DPAJAX at DepressedPress.com
This very simple example creates one request with three calls and then passes that information, in the call order, to a single handler:
// The handler function
function AddUp(Nums) { alert(Nums[1] + Nums[2] + Nums[3]) };
// Create the pool
myPool = DP_AJAX.createPool();
// Create the request
myRequest = DP_AJAX.createRequest(AddUp);
// Add the calls to the request
myRequest.addCall("GET", "http://www.mysite.com/Add.htm", [5,10]);
myRequest.addCall("GET", "http://www.mysite.com/Add.htm", [4,6]);
myRequest.addCall("GET", "http://www.mysite.com/Add.htm", [7,13]);
// Add the request to the pool
myPool.addRequest(myRequest);
Note that unlike many of the other solutions provided this method does not force single threading of the calls being made - each will still run as quickly as the environment allows but the handler will only be called when all are complete. The component also supports user-defined numbers of requests so you can force single-threading easily if you like. It also supports the setting of timeout values and retry attempts if your service is a little flakey.
I've found it insanely useful (and incredibly simple to understand) for this kind of work.