Piping Value: Ajax + JQuery - javascript

I have a function in which I execute an ajax request and wait till I get a response and return a value but the value returned is undefined. What is wrong?
function GetVMData(url_s){
return $.ajax({
url: url_s,
crossDomain: true,
dataType: 'jsonp',
error: function(xhr, status, error) {
alert('failed')
}
}).pipe(function(data) { return data[4]; });
}
If I print the value of data[4] within the ajax callback it prints the right value, therefore i know the request is going through but when I try this:
var cord;
cord = GetVMData(url).done(function(cpu_USG) {
return cpu_USG;
});
alert(cord)
the value of cord is wrong.

var cord;
cord = GetVMData(url).done(function(cpu_USG) {
return cpu_USG;
});
alert(cord)
This code runs asynchronously. So you need to perform everything in the callback, like:
GetVMData(url).done(function(cpu_USG) {
alert(cpu_USG);
});

Here:
var cord;
cord = GetVMData(url).done(function(cpu_USG) {
return cpu_USG;
});
alert(cord);
cord contains object, not the value. And by the way, you don't know where ajax calling will be finished, so you should be familiar with idea of callbacks..
As an example:
function makeRequest(url, callback) {
$.ajax({
url: url,
crossDomain: true,
dataType: 'jsonp',
error: function(xhr, status, error) {
alert('failed')
},
success: callback
});
}
var do_something = function (data) {
alert(data[4]);
};
cord = makeRequest(url, do_something);

Related

Await ajax call in JavaScript

I know that there's many questions and answers about this but I'm new to JavaScript and I'm facing problem with async/ await function. I have two function : getInvoices() where I have a ajax call to get the needed data, and loadBarChart(data) that renders a bar chart. For the chart I'm using ApexCharts. So I first call getInvoices() function to get the data and then I call loadBarChart(data) passing the data like this:
$(document).ready(function () {
var data = getInvoices();
console.log(data); // data is undefined
loadBarChart(data);
});
The data is always undefined probably because the ajax call is not done jet.
Here is getInvoices() function code:
function getInvoices() {
var url = "#Url.Action("GetInvoiceCustum");
$.ajax({
type: "GET",
dataType: "json",
url: url,
success: function (data) {
return data;
},
error: function (jqXHR, textStatus, errorThrown) {
alert(textStatus);
}
});
}
Following this I changed the code, but at the end I don't know how to pass the data from getInvoices() to loadBarChart(data);
So far this is what I have :
$(document).ready(function () {
var url = "#Url.Action("GetInvoiceCustum");
var ajax1 = new Promise((resolve, reject) => {
$.ajax({
type: "GET",
url: url,
success: function (data) {
resolve("OK");
result = data;
},
error: function () {
reject(" ERROR");
},
});
});
//At this point how can I acces the result from ajax call, and call the loadBarChart(data)
ajax1.then(values => {
console.log(values)
}, reason => {
console.log("Errors: " + reason)
});
ajax1.then(function (data1) {
var data = data1.result;
console.log(a);
return data1.result;
//loadBarChart(data);
})
});
Doing this how can I access the data that returns getInvoices() and then call loadBarChart(data), or there are other ways to make this posible?
You can call the second function in success of the first function like
$.ajax({
type: "GET",
url: url,
success: function (data) {
loadBarChart(data);
},
error: function () {
reject(" ERROR");
},
});

Handing value into Success function from AJAX Call

G'day all,
I'm trying to pass a value through to a Success var from the original AJAX call.
Here's some code :
function isJobComplete(jobGUID) {
var data = { "pJobGUID": jobGUID };
var url = '/DataService.asmx/isJobComplete';
var success = function (response, jobGUID) {
if (response.d) {
//The job is complete. Update to complete
setJobComplete(jobGUID);
}
};
var error = function (response) {
jAlert('isJobComplete failed.\n' + response.d);
};
sendAjax(data, url, success, error);
}
function sendAjax(data, url, success, error) {
$.ajax({
type: "POST",
url: url,
data: JSON.stringify(data),
contentType: "application/json; charset=utf-8",
dataType: "json",
success: success,
error: error || function (response) {
jAlert(response.d);
}
});
}
When the isJobComplete function runs, it has the correct value for jobGUID on the first pass through, but on the return to Success after the AJAX call, jobGUID changes to the word "success", with the double quotes.
How can I pass through that jobGUID to the Success function so I can use it to do more work depending on the AJAX response?
Thanks in advance....

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);
}

jQuery. Assign JSON as a result to a variable

I use this helper function to receive JSON results for my requests:
function getData(url) {
$.get(url,
function(data) {
response = data;
return response;
}, 'application/json');
}
I give it some string as a part of url from my web application, like '/api/getusers', so it looks like getData('/api/getusers'). Now I need that string result containing JSON data that I receive from the url to be assigned to my variable, so it would look like this: var result = getData('/api/getusers'). Then I will process this JSON data. The problem is with the returning the response variable. It's undefined. Thanks!
try this
function getData(url) {
var data;
$.ajax({
async: false, //thats the trick
url: 'http://www.example.com',
dataType: 'json',
success: function(response){
data = response;
}
});
return data;
}
It's an asynchronous operation, meaning that function(data) { ... } runs later when the response from the server is available, long after you returned from getData(). Instead, kick off whatever you need from that function, for example:
function getData(url, callback) {
$.get(url, callback, 'application/json');
}
Then when you're calling it, pass in a function or reference to a function that uses the response, like this:
getData("myPage.php", function(data) {
alert("The data returned was: " + data);
});
Use $.ajax
$.ajax({
url: 'http://www.example.com',
dataType: 'json',
success: function(data){
alert(data.Id);
}
});

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