jQuery: JSON callback function never reached - ajax

I'm requesting a page via JSON but never reach the callback-function. Does someone know why this is happening?
jQuery.getJSON("'. $dnd_fileupload_dir .'dnd-medialink.php?format=json&jsoncallback=?", function(data){
alert("lalala");
});

Use firebug to see what's going on. Either the request URI is incorrect and there is a 400 error, or the response is not valid JSON.

I would suggest downloading fiddler tool and using it to watch what is sent over http. A simple search on google will get you to the fiddler website

Related

How to get json data from Server with jquery mobile?

I am trying to get the Bitcoin course from a web server.
Then we try it with a JSON from local, it works.
In Firebug, I can see the get request to bitcoincharts.com, but there is no answer.
What's wrong with my code?
$('#LitecoinMenue').append('<p><b>Litecoin: 42</b></p>');
$.getJSON('http://api.bitcoincharts.com/v1/weighted_prices.json',
function(data){
$.each(data.USD, function(index,item){
$('#BitcoinMenue').append('<p><b>Bitcoin:'+ item+'</b></p>');
});
});
The reason your code doesn't work is because of a rule called Same-origin policy. This rule requires that all AJAX requests are made to a file on the same domain name. It is not possible to use $.getJSON, or any other AJAX function to load a file from an external domain.
There are only a few options available, the most common is to create a PHP file to act as a proxy, and store it on the same domain. For example:
proxy.php
<?php
$url = base64_decode($_GET['url']);
return file_get_contents($url);
?>
Your page above
$('#LitecoinMenue').append('<p><b>Litecoin: 42</b></p>');
$.getJSON('proxy.php?url=aHR0cDovL2FwaS5iaXRjb2luY2hhcnRzLmNvbS92MS93ZWlnaHRlZF9wcmljZXMuanNvbg==',
function(data){
$.each(data.USD, function(index,item){
$('#BitcoinMenue').append('<p><b>Bitcoin:'+ item+'</b></p>');
});
});
Important Notes:
This is just an example. In a real life situation you would probably want to use cURL to get your file. You should also ensure that it is secured so that someone cannot use Firebug to send an AJAX request to fetch a big file (like a movie) or your server could crash.
As you can see, the URL is base64 encoded. This is to ensure that it gets processed correctly as sometimes there are issues when passing an unencoded URL as a GET parameter. You can encode and decode base64 strings with these online converters: http://base64encode.org and http://base64decode.org, or you can use the built in PHP functions base64_encode() and base64_decode().

Load data from ajax request (json) on startup in AngularJs

I have this simple page that just needs to show contents that is loaded from an external url (ajax request, response in json format)
I should say I'm a AngularJS newbie.
I've googled a bunch and found different ways of doing this and couldn't manage to determine which is the correct/simple/up-to-date way to achieve this.
My 2 challenges -
Making the AJAX request run on startup (I can load the page before that happens and just load the contents one the ajax request finishes. Maybe show a 'Loading..' indicator)
Doing a ajax request correctly.
Here is my attempt. I know that the ajax request is never made because its not setup correctly.
You are getting into .error function:
http://jsbin.com/oDUsuVA/3/edit
For jsonp your response should be something like:
callback([
{
"title":"License Title 1",
"licenseUrl":"http://cnn.com",
"licenseText": " test"
}]);
Edit:
You can simply do .get() request too, but if you had to use jsonp request interface, you would have to correct response.
A Jsonp request always wraps the logic into a json callback wrapper function.
I just did $http.get instead of your $http.jsonp and it did work for me.

IE8 - Geocode Ajax call never succeeds

Please excuse my bad english, I'm french ;)
SO, I've to make an Ajax call you this kind of url :
http://maps.googleapis.com/maps/api/geocode/json?latlng=45.85941212790755,0&sensor=true
With this code :
$.ajax({ url:'http://maps.googleapis.com/maps/api/geocode/json?latlng='+pos.coords.latitude+','+pos.coords.longitude+'&sensor=true',
success: function(results){
// ...
}
});
But it never succeeds for IE8 (It's ok for chrome and FF, IE9&10).
Have you got an idea ?
EDIT
My bad, in IE8 you cannot request a geocode from the client side any longer because google has removed JSONP support from their geocoder.
You can do one of two things
Use your own server as a proxy (I do this).
This basically means that you make a request to a script on your own server that uses cURL (or similar) to make a request to the google geocoder and then return the results back to you.
If you're using the google maps api, you have the option of using it's built-in geocoder (https://developers.google.com/maps/documentation/javascript/examples/geocoding-simple)
OLD REPLY
It's a cross domain call in IE8 - you'll get a No Transport error (or if you add jQuery.support.cors = true you'll still get an Access is Denied error.
Best solutions is to use JSONP. jQuery makes using JSONP trivial.
Check out this jQuery Docs page and scroll down to their example using JSONP with the Flickr API.

cross domain request with dojo

I am attempting a cross domain request with dojo. External url is of MIME type text/html the only content on the page is something like 1236. I tried
dojo.require("dojo.io.script");
dojo.ready(function() {
dojo.io.script.get({
url: "theexternalurl",
callbackParamName: "jsoncallback",
load: function(data) {
console.log(data);
}
});
});,
But that was no good. Any ideas on how this can be done with dojo?
I suspect you are bumping into the browser security here. Cross-domain requests will only work when using iframes or injecting scripts (as you have done) and when the content of that script is valid "text/javascript".
If you are trying to load "text/html" into the script, it won't work as it isn't a valid script. It is something most of us have tried to do at some point. I have spent hours trying to get around cross-domain restrictions and found the security blocking it to be solid.
See my answer here for more details.
If all you are trying to do is load the content onto the page then you could use an <iframe>. However, if you are trying to parse the loaded content in some way than I'm afraid it is a dead-end. Probably not the answer you were hoping for but it'll save you hours of frustration.

jQuery and Ajax with json - fails in IE

I'm using jQuery (1.7.0) to make a json/ajax call to Spotify. The following code works fine in Chrome and Firefox, but causes an error (Error: Access is denied.) in IE.
$.ajax({
url: 'http://ws.spotify.com/lookup/1/.json',
type: 'GET',
dataType: 'json',
cache: true,
data: {
uri: "someartist",
extras: "album"
},
success: successfn,
error:function(xhr, status, errorThrown) {
alert("networking error: "+errorThrown+'\n'+status+'\n'+xhr.statusText);
}
});
The success function is called in Chrome and FF, but the error function is called in IE with the above message. I have set cors to true: jQuery.support.cors = true;.
It works on Chrome and FF both locally and on my server, it works in IE locally but not on the server. Changing cache: false causes problems at the spotify end - doesn't line additional parameters, so I get a "bad request" error.
Grateful for any pointers.
Thanks
Abo
You are relying on the spotify url to give a Access-Control-Allow-Origin:* in their header to allow cross domain requests from all domains. Internet explorer however doesn't support this, so it gives access denied.
access-control-allow-origin explained. (TLDR: Servers may allow cross domain ajax in their headers)
If you need this to work in IE, you could use spotify's JSONP API if they have one or make the AJAX request in flash, which works in all browsers and passes the requests response data to your javascript.
The above answer about using jsonp is correct; I want to add:
Don't set
jquery.support.cors = true;
I'm not sure why so many questions begin by stating they took that step. This property is meant to be read to find out if the browser supports CORS. You should only override it if you know differently, and in my experience it's accurate for all major browsers. Setting it to true doesn't enable the browser to use CORS, it just denies you the info that CORS is going to fail.
http://api.jquery.com/jQuery.support/
can you give an example of returned data?
at a /guess/, it either has something to do with the filename ".json", or the JSON returned has something weird about it.
I'm surprised this works on Chrome or Firefox. You shouldn't be able to run cross-domain JSON requests.
If Spotify API supports it, you should use JSONP in order to access resources from other domains.
Also see: No response from jQuery ajax call
I don't see this working in FF. You can't make cross-domain Ajax calls. So I'm not sure what's going on when you say that it works in FF. But I just tried the following in FF and I got the error. So all you can do is make the call on the server side and then include the results in your page.
http://jsfiddle.net/2XWGn/

Resources