.ajax returning json object, but no success - javascript

I am using JQuery's .ajax method to call to a URL which returns a JSON encoded string. I can see the object returned from the GET in the debugger, but for some reason I'm not falling into the success function. Any ideas?
$.ajax({
type: "GET",
url: 'http://search.issuu.com/api/2_0/document?q=jamie',
dataType: "jsonp",
success: function(data){
alert('Success!');
}
});

If you look at the documentation, it shows that the proper way to make a jsonp request requires a jsonCallback parameter.
Code:
$.ajax({
type: "GET",
url: 'http://search.issuu.com/api/2_0/document?q=jamie&jsonCallback=?',
dataType: "jsonp",
success: function(data){
alert('Success!');
}
});
Fiddle: http://jsfiddle.net/xrk4z6ur/2/
jQuery will by default use callback=? for a jsonp request. In this case, the API accepts jsonCallback. Adding jsonCallback=? to the url will let jQuery handle it properly.

If you are using jsonp you should specify a callback GET parameter like &callback?
On server side return the callback with your desired data as argument (json encoded)

Related

Getting json on cross domain with jsonp using jquery

I have a very simple $.ajax call that is suppose to get the json data from a given url. Currently the url does get called and the data does get returned, however the localHsonpCallback function doesn't seem to get fired.
Here is my code.
function getBuildings(){
$.ajax({
url: 'http://localhost/api/users',
type: "GET",
dataType: "jsonp",
jsonpCallback: "localJsonpCallback"
});
}
function localJsonpCallback(json) {
console.log("Fired");
if (!json.Error) {
console.log("Fired");
}
else {
console.log("ERROR");
}
}
So as mentioned above for some reason the localJsonpCallback doesn't seem to get fired at all.
Also I should mention that in my Chrome Dev tools the request link ends up looking like this for reason
http://localhost/api/users?callback=localJsonpCallback&_=1429708885454
Any help in this question would be greatly appreciated.
Thank you.
Try the callback method as an anonymous function directly inside the parameter list.
function getBuildings(){
$.ajax({
url: 'http://localhost/api/users',
type: "GET",
dataType: "jsonp",
jsonpCallback: function(data){
console.log("Fired");
if (!data.Error) {
console.log("Fired");
}
else {
console.log("ERROR");
}
}
});
}
If youre not appending the callback onto the url you can set the jsonp oprion to false and then, as you are doing, set the callback in the options.
function getBuildings(){
$.ajax({
url: 'http://localhost/api/users',
type: "GET",
dataType: "jsonp",
jsonp: false,
jsonpCallback: "localJsonpCallback"
});
}
Since javascript is sequential its also a good idea to define your functions before theyre called. ie - define your callback function before your ajax call.
http://api.jquery.com/jQuery.ajax/
jsonp
Type:
String Override the callback function name in a JSONP request.
This value will be used instead of 'callback' in the 'callback=?' part
of the query string in the url. So {jsonp:'onJSONPLoad'} would result
in 'onJSONPLoad=?' passed to the server. As of jQuery 1.5, setting the
jsonp option to false prevents jQuery from adding the "?callback"
string to the URL or attempting to use "=?" for transformation. In
this case, you should also explicitly set the jsonpCallback setting.
For example, { jsonp: false, jsonpCallback: "callbackName" }
Maybe this piece of code it will help solve your problem:
$.ajax({
type: 'GET',
url: 'http://localhost/api/users',
data:{todo:"jsonp"},
dataType: "jsonp",
crossDomain: true,
cache:false,
success: success,
error:function(jqXHR, textStatus, errorThrown){
alert(errorThrown);
}
});
var success = function(data){
/* parse JSON */
data = $.parseJSON(data);
//your code here
};
This either a server side problem that the callback parameter is not used properly or the parameter name callback does not exist for the server side they are looking for something different.
You said the result is returning, what is the format? JSONP must return a script block not pure data so be sure the result is in below format.
{callbackFunctionName}({hugeDataFromServer});
Basically it is script that calls your function.
if it is not the server side that means it is more likely they are using a different name for callback parameter e.g. cb , _callback etc

jquery ajax : what is the actual request sent?

What is the actual url sent to the server when I use the jquery ajax? And how do I access that value? For example, consider the following code:
<script>
$.ajax({
type: "POST",
dataType: "json",
url: "response.php",
data: {name:'Smith',age:10},
success: function(data) {
...
}
beforeSend: function(){
console.log(url);
// what do I put here to see what is being sent
// I am expecting to see "response.php?name=Smith&age=10"
}
...
So essentially what variable holds "response.php?name=Smith&age=10".
Thanks.
No variable holds
response.php?name=Smith&age=10
because you aren't sending the data as a query string. This would happen if you issued a GET request, but doesn't with a POST request.
You're sending the data in the request body of an HTTP post. The data is the data that you assigned to the data parameter. You don't need to round-trip it through jQuery's ajax methods. You've got it already. It's:
{name:'Smith',age:10}
does jQuery's interpretation of your data really matter?
The settings object is fully populated when beforeSend is called:
beforeSend: function(jqXHR, settings) {
console.log(settings.url);
console.log(settings.data);
}
$.ajax({ type: "POST", ... }) will log
response.php
name=Smith&age=10
and type: "GET"
response.php?name=Smith&age=10
undefined

How do I post serialized data along with a jQuery.getScript() call?

Is it possible to request an external JS file while also posting serialized data in that same request? I'd like to pass along some values to validate the request, but not have those values be a part of the request url.
On the backend I'll process the posted values and return the proper JS after validation, then continue with the injected JS functions as a callback of getScript.
I see no data option in the API:
http://api.jquery.com/jQuery.getScript/
$.getScript is a shorthand Ajax function, which is equivalent to:
$.ajax({
url: url,
dataType: "script",
success: success
});
So I assume You can use the following code to do that
$.ajax({
url: url,
data: {data: serializedData},
dataType: "script",
success: success
});

How to get a value from a JSON hash

In a jquery ajax call I get sent back some JSON from the server and want to use some of it in the success callback. I pass in the data, but how do I get at a specific value (say "id")?
I tried this but I get undefined:
success : function(data) {
alert(data["id"]);
},
Your ajax request should look something like this:
$.ajax({
url: "...",
dataType: "json",
success: function(data){
alert(data.id);
});

Jquery Ajax Problem

Hi all;
var v_name = null;
$.ajax({
type: "GET",
url: "Testpage.aspx",
data: "name=test",
dataType: "html",
success: function(mydata) {
$.data(document.body, 'v_name', mydata);
}
});
v_name = $.data(document.body, 'OutputGrid');
alert(v_name);
first alert undefined before alert work why ?
In addition to the other answers, also keep in mind that by default .ajax GET requests are cached, so depending on your browser, it may look like all of your requests are returning the same response. Workarounds include (but are not limited to): using POST instead of GET, adding a random querystring to your url for each request, or adding 'cache: false' to either your ajax call or to the global ajaxSetup.
To make it work, you have to place the alert() in the success function:
$.ajax({
type: "GET",
url: "Testpage.aspx",
data: "name=test",
dataType: "html",
success: function(mydata) {
alert(mydata);
}
});
AJAX calls are asynchronous, and therefore JavaScript would evaluate alert(v_name); before the server responds to the AJAX call, and therefore before the success function is called.
Your AJAX applications must be designed in such a way to be driven by the AJAX response. Therefore anything you plan to do with mydata should be invoked from the success function. As a rule of the thumb, imagine that the server will take very long (such as 1 minute) to respond to the AJAX request. Your program logic should work around this concept of asynchrony.
$.ajax({
type: "GET",
url: "Testpage.aspx",
data: "name=test",
dataType: "html",
success: function(mydata) {
alert(mydata);
}
});

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