Develop Reference

how to detect a server error into a jquery ajax call?

I use Jquery to parse an json from url: the code is like this:
function fetchdata() {
var statusUrl = '/api/desk/j/';
$.ajax({
url: statusUrl,
dataType: "json",
type: 'post',
success: function(response) {
alert('ok');
},
error: function(xhr, status, error) {
var err = JSON.parse(xhr.responseText);
alert(err.message);
}
});
}
everything works fine, but if the server is not reachable I'm not able to detect it: I tried to do something in error: function, but seems that the code in error is fired only if the json has an error
have you got some ideas?
thank you!

You need to test the statusText from the jQuery textStatus response object. You can take advantage of your browser's developer console to inspect this object. You can expand the properties and methods for your perusal, however you wanna use it. Just click on the returned message of the console.log() to see these properties and methods that you wan't to use for error detection.
function fetchdata() {
var statusUrl = '/api/desk/j/';
$.ajax({
url: statusUrl,
dataType: "json",
type: 'post',
success: function(response) {
alert('ok');
},
error: function(textStatus) {
console.log(textStatus);
console.log(textStatus.statusText, textStatus.status);
}
});
}
fetchdata();

jQuery JSONP callback function not found

I'm trying to get data from external server using JSONP, but I've stuck on the callback function.
function processLinks(data) {
alert('IT WORKS!');
};
function getLinks() {
$.ajax({
type: 'GET',
url: 'https://external-site.com/test.cgi',
dataType: 'jsonp',
success: function (data) {
console.log(data)
}
});
};
When I call getLinks(), I get ReferenceError: processLinks is not defined.
External site returns processLinks({"mark": "dog", "number":"33"});.
Thank you for any help

Google API url use by javaScript

I have this url as json object which is provided by google API.
https://www.googleapis.com/customsearch/v1?key=AIzaSyAo6DqmlMti9ID7lL532A7-6Miu1QHcMqI&cx=013881670411723352605:b1y6-jfsiki&q=web%20developer?alt=json-in-script&callback=listEvents
I want to use javaScript and want to see complete json object.This is my script code , but it doesn't work. please help me , i am struggling from 3 days.
function listEvents(root){
$.getJSON('https://www.googleapis.com/customsearch/v1?key=AIzaSyAo6DqmlMti9ID7lL532A7-6Miu1QHcMqI&cx=013881670411723352605:b1y6-jfsiki&q=web%20developer?alt=json-in-script&callback=listEvents', function(data) {*/
alert(root)
});
}
function init() {
listEvents();
}
window.onload = init;
Thanks in advance

You are giving a callback option in url that is again a call to listEvents(). That is not correct. Use your own success callback. this will work:
function listEvents() {
$.getJSON('https://www.googleapis.com/customsearch/v1?key=AIzaSyAo6DqmlMti9ID7lL532A7-6Miu1QHcMqI&cx=013881670411723352605:b1y6-jfsiki&q=web%20developer?alt=json-in-script', function (data) {
console.log(data)
});
}
Demo example

The output is in JSONP format and not JSON
JSONP({JSON})
Jquery JSONP: http://learn.jquery.com/ajax/working-with-jsonp/
(function($) {
var url = 'https://www.googleapis.com/customsearch/v1?key=AIzaSyAo6DqmlMti9ID7lL532A7-6Miu1QHcMqI&cx=013881670411723352605:b1y6-jfsiki&q=web%20developer?alt=json-in-script&callback=listEvents';
$.ajax({
type: 'GET',
url: url,
async: false,
jsonpCallback: 'listEvents',
contentType: "application/json",
dataType: 'jsonp',
success: function(json) {
console.dir(json);
},
error: function(e) {
console.log(e.message);
}
});
})(jQuery);
BTW your Google Daily Limit Exceeded

AJAX - Cross-domain don't work

I was reading many things about that the json is great replacement for XMLHttpRequests. I tried it and it don't works:
$.ajax({
crossDomain: true,
url: settingsURL,
type: "POST",
dataType: 'JSONP',
parseAsHtml: true, cli: 'help',
success: function(data) {
data=$(data).find('div#TestDivContent');
$('#TestDivContent').append(data);
},
error: function() {
$('#TestDivContent').append("<p>Can't Connect</p>");
}
});
and im getting...
Uncaught SyntaxError: Unexpected token <

Please Check the code below that is working like a charm in Cross Domain ().
if You Have control of both the Domains i.e., Domain1.com & Domain2.com
//Ajax Script in Domain1.com
//No Conflict is the code snippet from my sample code You can delete it if not required no issues
<script type="text/javascript">jq1102 = jQuery.noConflict( true );</script>
<script type="text/javascript" >
function jsonp(n){
//GET Response is Here
alert(n);
}
jq1102(function(){
jq1102.ajax({
type: "GET",
dataType: "jsonp",
url: 'http://domain2.com/ClientSiteApi/',
crossDomain: true,
complete: function(data){
//Any Action You Like to Trigger After Complete
},
error: function(jqXHR, textStatus, ex) {
//Nothing to Change Here
}
});
})
</script>
Response from Domain2.com
echo 'jsonp("hello")'; //You Can place JSON string in replace of the Hello String

Revealing module pattern method echo undefined

I wrote this function as revealing module pattern, but when I call the get method in console by metadataModule.get(); it echoes undefined in console.
var metadataModule = function () {
var metadataurl = 'http://farskids326.com/data.json';
function getMetadata() {
console.log("Metadata Function Called")
$.ajax({
url: metadataurl,
dataType: "json",
success: function (data) {
console.log(data);
}
});
}
return {
get: getMetadata,
};
}();
Where did I made a mistake in this code?

When you are working in the console, the return value of the last expresion is echoed after any command. The method you are using doesn't have an explicit return value. So, that may be why you see undefined.
This probably means that your ajax call is encountering an error. Try changing it to log when either success or error happens, like so:
$.ajax({
url: metadataurl ,
dataType: "json",
success: function(data){
console.log('called success!');
},
error: function(jqXHR, textStatus, errorThrown){
console.log('called error!');
}
});
Then, when you run your code, you should see exactly which callback is being executed. Hopefully, that will give you a good starting point for debugging the issue.

The getMetadata function returns nothing so yes, it will output undefined. for it to respond with the content of the JSON you need to make the ajax call synchronous and return the value you get.
var metadataModule = function () {
var metadataurl = 'http://farskids326.com/data.json';
function getMetadata() {
console.log("Metadata Function Called")
var content = {}
$.ajax({
url: metadataurl,
async : false,
dataType: "json",
success: function (data) {
content = data;
}
});
return content
}
return {
get: getMetadata,
};
}();