I have this method:
var chineseCurrency = getChinese();
function getChinese(){
return $.ajax({
context: this,
type: 'GET',
dataType: 'json',
url: "https://www.cryptonator.com/api/ticker/usd-cny"
});
}
That is what printed when console.log(chineseCurrency);:
I am not able to make chineseCurrency equal to "price", so it would be "6.80071377". How can I do that? Tried chineseCurrency.responseText, nope, chineseCurrency['responseText'], nope. Tried to JSON.parse(chineseCurrency), nope. Nothing works!
Sorry if repeated, couldn't find any answer at Stackoverflow.
How do I return the response from an asynchronous call?
Data that is received as response to asynchronous ajax call cannot be returned from the function that calls $.ajax. What you are returning is XMLHttpRequest object (see http://api.jquery.com/jquery.ajax/) that is far from the desired data.
var chineseCurrency = null;
function getChinese(){
return $.ajax({
context: this,
type: 'GET',
dataType: 'json',
url: "https://www.cryptonator.com/api/ticker/usd-cny",
success: function(data) {
alert("success1: chineseCurrency=" + chineseCurrency);
chineseCurrency = data.ticker.price;
alert("success2: chineseCurrency=" + chineseCurrency);
// do what you need with chineseCurrency
}
});
}
You are not taking the data from that is returned from the Ajax call. instead you are just returning the ajax object.
Change your code to :
$.ajax(
{
context: this,
type: 'GET',
dataType: 'json',
url: "https://www.cryptonator.com/api/ticker/usd-cny"
data :{},
error : function(data)
{
console.log('error occured when trying to find the from city');
},
success : function(data)
{
console.log(data); //This is what you should return from the function.
}
});
Related
I have an AJAX request which gets data from the database and then populates the page with the data collected. The problem I am having is that currently the ajax request is in a setInterval which is being called every second.
setInterval(function () {
$.ajax({
method: "POST",
url: "/PLM/FetchPageContent",
dataType: "json",
success: function (data) {
console.log(data);
}
});
}, 1000);
This is fetching the data every second which is a huge strain on the server as it's making a request and then I am calling it again even when the data hasn't come through first time.
Is there a way that I can call the same AJAX request over and over but only after it's finished fetching the data first time and not keep going up?
There are better architectures to accomplish this type of scenario (websockets as mentioned in the comments would be one example), but to do strictly what you're asking, sure! Wrap it in a function that calls itself:
function getData(){
$.ajax({
method: "POST",
url: "/PLM/FetchPageContent",
dataType: "json",
success: function (data) {
console.log(data);
getData();
}
});
}
Replace the setInterval with a setTimeout only once you're done:
function fetchAjax() {
$.ajax({
method: "POST",
url: "/PLM/FetchPageContent",
dataType: "json",
success: function (data) {
console.log(data);
setTimeout(fetchAjax, 1000);
}
});
};
Add a variable to distunguish if ajax call is already underway. If it is, don't do anything. If not, go ahead.
var isAjaxInProgress = false;
setInterval(function () {
if (!isAjaxInProgress){
isAjaxInProgress = true;
$.ajax({
method: "POST",
url: "/PLM/FetchPageContent",
dataType: "json",
success: function (data) {
console.log(data);
isAjaxInProgress = false;
}
});
}
}, 1000);
I have an ajax function call that has a variable sum with value as 5. But when I try to access this variable outside the ajax function call, am getting null value.
Is there any way to access the value outside the ajax function?
$.ajax({
type: "POST",
url: "Service.asmx/chart",
data: appid,
success: function(data) {
var mydata = 5;
}
});
alert(mydata);
Try this:
$.ajax({
type: "POST",
url: "Service.asmx/chart",
data: appid,
success: function(data) {
doGetMyData(data);
}
});
function doGetMyData(data){
alert(data);
}
The first "A" in AJAX means Asynchronous, so your code runs the alert before the request completes. To achieve the goals you want, you may try to make your request synchronous adding the async:false option to your query:
$.ajax({
type: "POST",
url: "Service.asmx/chart",
data: appid,
async:false,
success: function(data) {
doGetMyData(data);
}
});
function doGetMyData(data){
alert(data);
}
The bad news is synchronous request locks your browser until it's finish, it's a good pratice to avoid this.
This question already has answers here:
How do I return the response from an asynchronous call?
(41 answers)
Closed 7 years ago.
I have an ajax call in a function and I did not find a solution how to return the data:
function get_blog_post(id){
var info="id="+id;
$.ajax({
type: 'POST',
url: 'get_blog_post.php',
data: info,
success: function(data){
return data;
}
});
}
The code above doesn't works. The data contains the right answer but I can't use it if I callthe get_blog_post() function.
:\
function get_blog_post(id, callback){
var info="id="+id;
$.ajax({
type: 'POST',
url: 'get_blog_post.php',
data: info,
success: function(data){
callback(data);
}
});
}
get_blog_post(5, function(data){
// use data here
});
OR set async = false (not recommended):
$.ajax({
type: 'POST',
url: 'get_blog_post.php',
data: info,
async: false,
success: function(data){
return data;
}
});
The success function runs some time after the ajax call completes. That's the nature of asynchronous calls--like ajax in javascript.
That means you cant return it and have to do something with the data in that function. Perhaps it is text and you put it into a text area like:
success: function(data){
$('textarea').val(data);
}
Provide a callback method and do what ever you want to do inside it
function get_blog_post(id, callback){
var info="id="+id;
$.ajax({
type: 'POST',
url: 'get_blog_post.php',
data: info,
success: callback
});
}
I am using Ajax to add contents on my database. And here's the code:
function addToFavorites(){
var recipe_id = $("#recipe_id").val();
var url = connect_url+'addFavorite.php?user_id='+user_id+'&recipe_id='+recipe_id;
$.ajax({
type: 'POST',
data: [{
user_id: user_id,
recipe_id: recipe_id
}],
url: url,
async: true,
jsonpCallback: 'userCallback',
contentType: "application/json",
dataType: 'jsonp',
success: function (data) {
alert("HELLO!!!");
},
error: function (e) {
alert("ERROR!");
}
});
}
The Ajax call was successful and I was able to add records on the database but I'm just wondering why is it not displaying the alert message if the calling was successful? Is there something wrong with my code? Or is there something wrong with my understanding? Thanks!
you must give a response with some info to the ajax or it won't know the response succeeded
This works fine:
jQuery('#my_get_related_keywords').click(function() {
if (jQuery('#my_keyword').val() == '') return false;
jQuery.getJSON("http://boss.yahooapis.com/ysearch/web/v1/"
+jQuery('#my_keyword').val()+"?"
+"appid=myAppID"
+"&lang=en"
+"&format=json"
+"&count=50"
+"&view=keyterms"
+"&callback=?",
function (data) {//do something}
This returns 400 Bad Request (Just a reformulation of the above jQuery using .ajax to support error handling).
jQuery('#my_get_related_keywords').click(function()
{
if (jQuery('#my_keyword').val() == '') return false;
jQuery('#my_loader').show();
jQuery.ajax(
{
url: "http://boss.yahooapis.com/ysearch/web/v1/"
+jQuery('#my_keyword').val()+"?"
+"appid=myAppID"
+"&lang=en"
+"&format=json"
+"&count=50"
+"&view=keyterms"
+"&callback=?",
success: function(data)
{//do something}
I think you just need to add 2 more options (contentType and dataType):
$('#my_get_related_keywords').click(function() {
$.ajax({
type: "POST",
url: "HERE PUT THE PATH OF YOUR SERVICE OR PAGE",
data: '{"HERE YOU CAN PUT DATA TO PASS AT THE SERVICE"}',
contentType: "application/json; charset=utf-8", // this
dataType: "json", // and this
success: function (msg) {
//do something
},
error: function (errormessage) {
//do something else
}
});
}
Add this to your ajax call:
contentType: "application/json; charset=utf-8",
dataType: "json"
Late answer, but I figured it's worth keeping this updated. Expanding on Andrea Turri answer to reflect updated jQuery API and .success/.error deprecated methods.
As of jQuery 1.8.* the preferred way of doing this is to use .done() and .fail(). Jquery Docs
e.g.
$('#my_get_related_keywords').click(function() {
var ajaxRequest = $.ajax({
type: "POST",
url: "HERE PUT THE PATH OF YOUR SERVICE OR PAGE",
data: '{"HERE YOU CAN PUT DATA TO PASS AT THE SERVICE"}',
contentType: "application/json; charset=utf-8",
dataType: "json"});
//When the request successfully finished, execute passed in function
ajaxRequest.done(function(msg){
//do something
});
//When the request failed, execute the passed in function
ajaxRequest.fail(function(jqXHR, status){
//do something else
});
});
Be sure and use 'get' or 'post' consistantly with your $.ajax call for example.
$.ajax({
type: 'get',
must be met with
app.get('/', function(req, res) {
===============
and for post
$.ajax({
type: 'post',
must be met with
app.post('/', function(req, res) {
I was getting the 400 Bad Request error, even after setting:
contentType: "application/json",
dataType: "json"
The issue was with the type of a property passed in the json object, for the data property in the ajax request object.
To figure out the issue, I added an error handler and then logged the error to the console. Console log will clearly show validation errors for the properties if any.
This was my initial code:
var data = {
"TestId": testId,
"PlayerId": parseInt(playerId),
"Result": result
};
var url = document.location.protocol + "//" + document.location.host + "/api/tests"
$.ajax({
url: url,
method: "POST",
contentType: "application/json",
data: JSON.stringify(data), // issue with a property type in the data object
dataType: "json",
error: function (e) {
console.log(e); // logging the error object to console
},
success: function () {
console.log('Success saving test result');
}
});
Now after making the request, I checked the console tab in the browser development tool.
It looked like this:
responseJSON.errors[0] clearly shows a validation error: The JSON value could not be converted to System.String. Path: $.TestId, which means I have to convert TestId to a string in the data object, before making the request.
Changing the data object creation like below fixed the issue for me:
var data = {
"TestId": String(testId), //converting testId to a string
"PlayerId": parseInt(playerId),
"Result": result
};
I assume other possible errors could also be identified by logging and inspecting the error object.
Your AJAX call is not completed with the following two params.
contentType: "application/json; charset=utf-8",
dataType: "json"
contentType is the type of data you're sending
dataType is what you're expecting back from the server
In addition try to use JSON.stringify() method. It is used to turn a javascript object into json string.