before I explain my issue I would like to mention that I'm a naive on jsonp. This is actually my very first attempt to work with JSONP.
Im using jquery ajax call to pullback data from a website.
my jquery code is below
$.fn.checkTPS = function(){
return this.each(function(){
var interval;
$(this).on('keyup', function() {
var api_key = 'asdfasfsadfsadfsad';
var format = 'json';
var username = 'dame#example.co.uk';
var self = $(this);
var selfValue;
var feedback = $('.tps-feedback');
if(interval === undefined){
interval = setInterval(function(){
if(selfValue !== self.val()) {
selfValue = self.val();
if (selfValue.length > 9){
$.ajax({
url: 'https://www.selectabase.co.uk/api/v1/tps/' + selfValue + '/',
type: 'get',
dataType: 'jsonp',
data: {
format: format,
username: username,
api_key: api_key
},
success: function(data) {
console.log(data);
},
error: function() {
},
jsonp: 'jsonp'
});
}
}
},3000);
}
});
});
};
I want to accommodate a service from selectabase.co.uk, according to them this is how I should use the service https://www.selectabase.co.uk/api/v1/tps/[number]/?format=json&username=[username]&api_key=[api key]
when I send request using ajax I get this error Uncaught SyntaxError: Unexpected token : and when clicked this opens up
{"ctps": false, "number": "1452500705", "resource_uri": "/api/v1/tps/01452500705/", "tps": false} by the way this I want but don't know what's this error is unexpected token :
I've copied the following link from inspect element tab (you can see the image below) I think this is the call that has been generated by json https://www.selectabase.co.uk/api/v1/tps/01452500705/?jsonp=jQuery17102731868715648129_14120077325500&format=json&username=dame40example.co.uk&api_key=asdfasfsadfsadfsad&_=14120077325500
I copied the link below from inspect element > source tab in chrome.. I think I should add an image to describe properly where this json data and link I've copied from.
I hope I've manage to convey my message across... please help if you have any Idea what do i need to add... Regards
The format=json in your query string should probably be format=jsonp. The server is replying with JSON, but you're expecting a JSONP response. But I don't know that they support format=jsonp, it's just a guess.
Alternately, if that server supports CORS and allows requests from your origin, you could handle JSON instead (just remove dataType: "json" from your ajax call). Beware that that would require that the user be using a browser that properly supports CORS, which IE8 and IE9 don't. (They support CORS, but not via the normal XMLHttpRequest object, and this is a browser inconsistency that jQuery doesn't smooth over for you. If you search, though, you can find "plugins" or similar that will handle it.)
I am working with an API from another website and I am trying to get a JSON object back. Unfortunately due to the site origin issue I have to use JSONP to retrieve my data.
The function is working but I am stack on how to sanitize the data coming as a JSONP format to be able to use it as JSON?
This is my function
$('.loginForm').click(function(){
var url = 'https//api.example.com';
$.ajax({
type:'GET',
url: url,
dataType: 'jsonp',
error: jsonpCallback,
success: jsonpCallback,
jsonp: "callback"
});
function jsonpCallback(response){
console.log(response);
}
});
EDIT
This is the response I get before the error
Object { readyState=4, status=200, statusText="success", more...}
And this is the error i'm getting
SyntaxError: missing ; before statement
{"accountID":1328031,"authToken":"D81CDCB......
I went through every post in SO and the web in general to find where I am making a mistake but so far I can't find anything.
If you are getting the response in jsonP then you can use jXHR for making cross domain request , below is the link of jXHR (Library) :
https://gist.github.com/1576277/f4aead6741e0d7b0c40db6601048d9db6be1a5f9
And here is an example to use jXHR :
function sendRequest()
{
var xhrReq = new jXHR();
xhrReq.onreadystatechange = function(data)
{
if (xhrReq.readyState === 4)
{
//data contains your jsonp response..
}
};
var url = "http://" + SERVER_NAME + "yourCodeFile.aspx?callback=?";
xhrReq.open("GET",url);
xhrReq.send();
}
Always remember to add 'callback=?' as a query string parameter in url for jXHR request as the respone is jsonP.
Hope this helps you.
try using JSON.parse
function jsonpCallback(response){
console.log(JSON.parse(response));
}
A little background:
I am trying to implement and AJAX powered SlickGrid. There isn't much documentation so I used this example as a base.
In this example there is the following code that hits the desired web service to get the data:
req = $.jsonp({
url: url,
callbackParameter: "callback",
cache: true, // Digg doesn't accept the autogenerated cachebuster param
success: onSuccess,
error: function(){
onError(fromPage, toPage)
}
});
req.fromPage = fromPage;
req.toPage = toPage;
I'm not exactly sure what jsonp does but from what i've read it appears to be very similar to the ajax method in jQuery except it returns json and allows cross domain requests. The webservice that I happen to be calling only returns XML so I changed this chunk of code to:
req = $.ajax({
url: "/_vti_bin/lists.asmx",
type: "POST",
dataType: "xml",
data: xmlData,
complete: onSuccess,
error: function (xhr, ajaxOptions, thrownError) {
alert("error: " + xhr.statusText);
alert(thrownError);
},
contentType: "text/xml; charset=\"utf-8\""
});
req.fromPage = fromPage;
req.toPage = toPage;
My issue is that my page errors out at req.fromPage = fromPage; because req is null.
Am I wrong to think that I can just replace my jsonp call with a call to the ajax method? Is req just not set because my ajax call hasn't finished by the time that code is executed? How can I get around either of these issues?
If I comment out the last two lines and hard-code those values elsewhere everything runs fine.
Am I wrong to think that I can just replace my jsonp call with a call to the ajax method?
No, that should work just fine.
Is req just not set because my ajax call hasn't finished by the time that code is executed?
Yes, that is correct.
The ajax methods starts the request and returns immediately. If you want to do something after the response has arrived you should do that in the success event handler.
You might actually want to use the success event instead of the complete event, as the complete event happens even if there is an error.
You could specify async: false, in your settings to make the ajax call wait for the response, but that means that the browser freezes while it's waiting.
As Guffa stated, $.ajax() works asynchronically. Thus, you have to specify a callback that will be called when the request has returned a response, rather than to just use whatever $.ajax() returns.
There are a couple of different callback methods you can specify:
complete - runs when you recieve a response, regardless of its status.
success - runs when you recieve a response with a successful status code (usually 200).
error - runs when you recieve a response with an error code (for example 404 or 500).
To do something with the response body after a successful request, you should do something like
$.ajax({
...
success: function(body) {
alert('This is the method body:' + body);
}
});
Read up in the documentation on the different methods to see what more parameters you can use.
The following javascript code gives me ">success-<", i.e. empty data. Pasting the url in my browser gives me the expected content.
$.get("http://company.tld/wiki/api.php?action=query&titles=Page%20Title&format=xml&prop=revisions&rvprop=content", function (data, status) {
alert(">" + status + "-" + data + "<");
});
It's a MediaWiki wiki. Here's the MediaWiki API specification: http://www.mediawiki.org/wiki/API:Query
Why am I not getting any data?
You might breach the ajax cross domain policy there.
Is that domain you try to access yours? better said, the one from your script?
From my experience, if you try to access data from a foreign domain, the success handler will fire regardless. But as you describe, with no data at all.
If data is an object you will receive the close results. Try use typeof data in the alert.
UPDATED:
To jAndy: In the documentation of jQuery.ajax we can read following (see http://docs.jquery.com/Ajax_Events):
success (Local Event).
This event is only called if the request was successful (no errors from the server, no errors with the data).
I just tried execute the following code
try {
$.ajax({url:"http://en.wikipedia.org/w/api.php?action=query&titles=jQuery&format=xml&prop=revisions&rvprop=content",
success: function (data, status, x) {
alert ("ok");
},
error: function (data, status, x) {
alert ("not ok");
},
dataType:"xml"});
} catch (e) {
alert ("exception");
};
where I try to use a crossdomain call. In IE I can see "exception" alert. In Chrome and Firefox: "not ok". The function success will NOT be called in case of error.
So the data from server are really an empty string ("") for the url of Tobbe.
To Tobbe: you should add the last parameter "xml" probably.
Is it possible to catch an error when using JSONP with jQuery? I've tried both the $.getJSON and $.ajax methods but neither will catch the 404 error I'm testing. Here is what I've tried (keep in mind that these all work successfully, but I want to handle the case when it fails):
jQuery.ajax({
type: "GET",
url: handlerURL,
dataType: "jsonp",
success: function(results){
alert("Success!");
},
error: function(XMLHttpRequest, textStatus, errorThrown){
alert("Error");
}
});
And also:
jQuery.getJSON(handlerURL + "&callback=?",
function(jsonResult){
alert("Success!");
});
I've also tried adding the $.ajaxError but that didn't work either:
jQuery(document).ajaxError(function(event, request, settings){
alert("Error");
});
Here's my extensive answer to a similar question.
Here's the code:
jQuery.getJSON(handlerURL + "&callback=?",
function(jsonResult){
alert("Success!");
})
.done(function() { alert('getJSON request succeeded!'); })
.fail(function(jqXHR, textStatus, errorThrown) { alert('getJSON request failed! ' + textStatus); })
.always(function() { alert('getJSON request ended!'); });
It seems that JSONP requests that don't return a successful result never trigger any event, success or failure, and for better or worse that's apparently by design.
After searching their bug tracker, there's a patch which may be a possible solution using a timeout callback. See bug report #3442. If you can't capture the error, you can at least timeout after waiting a reasonable amount of time for success.
Detecting JSONP problems
If you don't want to download a dependency, you can detect the error state yourself. It's easy.
You will only be able to detect JSONP errors by using some sort of timeout. If there's no valid response in a certain time, then assume an error. The error could be basically anything, though.
Here's a simple way to go about checking for errors. Just use a success flag:
var success = false;
$.getJSON(url, function(json) {
success = true;
// ... whatever else your callback needs to do ...
});
// Set a 5-second (or however long you want) timeout to check for errors
setTimeout(function() {
if (!success)
{
// Handle error accordingly
alert("Houston, we have a problem.");
}
}, 5000);
As thedawnrider mentioned in comments, you could also use clearTimeout instead:
var errorTimeout = setTimeout(function() {
if (!success)
{
// Handle error accordingly
alert("Houston, we have a problem.");
}
}, 5000);
$.getJSON(url, function(json) {
clearTimeout(errorTimeout);
// ... whatever else your callback needs to do ...
});
Why? Read on...
Here's how JSONP works in a nutshell:
JSONP doesn't use XMLHttpRequest like regular AJAX requests. Instead, it injects a <script> tag into the page, where the "src" attribute is the URL of the request. The content of the response is wrapped in a Javascript function which is then executed when downloaded.
For example.
JSONP request: https://api.site.com/endpoint?this=that&callback=myFunc
Javascript will inject this script tag into the DOM:
<script src="https://api.site.com/endpoint?this=that&callback=myFunc"></script>
What happens when a <script> tag is added to the DOM? Obviously, it gets executed.
So suppose the response to this query yielded a JSON result like:
{"answer":42}
To the browser, that's the same thing as a script's source, so it gets executed. But what happens when you execute this:
<script>{"answer":42}</script>
Well, nothing. It's just an object. It doesn't get stored, saved, and nothing happens.
This is why JSONP requests wrap their results in a function. The server, which must support JSONP serialization, sees the callback parameter you specified, and returns this instead:
myFunc({"answer":42})
Then this gets executed instead:
<script>myFunc({"answer":42})</script>
... which is much more useful. Somewhere in your code is, in this case, a global function called myFunc:
myFunc(data)
{
alert("The answer to life, the universe, and everything is: " + data.answer);
}
That's it. That's the "magic" of JSONP. Then to build in a timeout check is very simple, like shown above. Make the request and immediately after, start a timeout. After X seconds, if your flag still hasn't been set, then the request timed out.
I know this question is a little old but I didn't see an answer that gives a simple solution to the problem so I figured I would share my 'simple' solution.
$.getJSON("example.json", function() {
console.log( "success" );
}).fail(function() {
console.log( "error" );
});
We can simply use the .fail() callback to check to see if an error occurred.
Hope this helps :)
If you collaborate with the provider, you could send another query string parameter being the function to callback when there's an error.
?callback=?&error=?
This is called JSONPE but it's not at all a defacto standard.
The provider then passes information to the error function to help you diagnose.
Doesn't help with comm errors though - jQuery would have to be updated to also callback the error function on timeout, as in Adam Bellaire's answer.
Seems like this is working now:
jQuery(document).ajaxError(function(event, request, settings){
alert("Error");
});
I use this to catch an JSON error
try {
$.getJSON(ajaxURL,callback).ajaxError();
} catch(err) {
alert("wow");
alert("Error : "+ err);
}
Edit: Alternatively you can get the error message also. This will let you know what the error is exactly. Try following syntax in catch block
alert("Error : " + err);
Mayby this works?
.complete(function(response, status) {
if (response.status == "404")
alert("404 Error");
else{
//Do something
}
if(status == "error")
alert("Error");
else{
//Do something
}
});
I dont know whenever the status goes in "error" mode. But i tested it with 404 and it responded
you ca explicitly handle any error number by adding this attribute in the ajax request:
statusCode: {
404: function() {
alert("page not found");
}
}
so, your code should be like this:
jQuery.ajax({
type: "GET",
statusCode: {
404: function() {
alert("page not found");
}
},
url: handlerURL,
dataType: "jsonp",
success: function(results){
alert("Success!");
},
error: function(XMLHttpRequest, textStatus, errorThrown){
alert("Error");
}
});
hope this helps you :)
I also posted this answer in stackoverflow - Error handling in getJSON calls
I know it's been a while since someone answerd here and the poster probably already got his answer either from here or from somewhere else. I do however think that this post will help anyone looking for a way to keep track of errors and timeouts while doing getJSON requests. Therefore below my answer to the question
The getJSON structure is as follows (found on http://api.jqueri.com):
$(selector).getJSON(url,data,success(data,status,xhr))
most people implement that using
$.getJSON(url, datatosend, function(data){
//do something with the data
});
where they use the url var to provide a link to the JSON data, the datatosend as a place to add the "?callback=?" and other variables that have to be send to get the correct JSON data returned, and the success funcion as a function for processing the data.
You can however add the status and xhr variables in your success function. The status variable contains one of the following strings : "success", "notmodified", "error", "timeout", or "parsererror", and the xhr variable contains the returned XMLHttpRequest object
(found on w3schools)
$.getJSON(url, datatosend, function(data, status, xhr){
if (status == "success"){
//do something with the data
}else if (status == "timeout"){
alert("Something is wrong with the connection");
}else if (status == "error" || status == "parsererror" ){
alert("An error occured");
}else{
alert("datatosend did not change");
}
});
This way it is easy to keep track of timeouts and errors without having to implement a custom timeout tracker that is started once a request is done.
Hope this helps someone still looking for an answer to this question.