I am using jsonp and ajax to query a web-service written in java on another server. I am using the following jquery command:
$.ajax({
type: "GET",
url: wsUrl,
data: {},
dataType: "jsonp",
complete: sites_return,
crossDomain: true,
jsonpCallback: "sites_return"
});
function jsonp_callback(data) {
console.log(data);
}
function sites_return(data) {
console.log(data);
}
So my problem is that after the query finishes a function called jsonp_callback is called. Where I can clearly see the json formatted string:
{"listEntries":["ELEM1", "ELEM2", "ELEM3", etc...]}
But after the function sites_return is called when the complete event fires, I get the the following:
Object { readyState=4, status=200, statusText="parsererror"}
Also for reference the jsonp_callback function is called before the sites_return function. Also if i take the jsonp_callback function out of the code, I get a complaint it firebug that the function is not implemented.
My question three fold:
1) What am i doing wrong on the jquery side?
2) Why does the json get parsed correctly in jsonp_callback but not sites_return?
3) What can i do to fix these issues?
EDIT
Some new development. Per the comments here is some additional information.
The following is what comes out of the http response
jsonp_callback({"listEntries":["ELEM1", "ELEM2", "ELEM3"]})
I assume this is the reason jsonp_callback is being called. I guess my question now becomes, is there any way to control this (assuming i don't have access to the back end web-service).
Hope this helps~
var url = "http://maps.google.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=false";
var address = "1600+Amphitheatre+Parkway";
var apiKey = "+Mountain+View,+CA";
$.getJSON("http://maps.google.com/maps/geo?q="+ address+"&key="+apiKey+"&sensor=false&output=json&callback=?",
function(data, textStatus){
console.log(data);
});
I believe that the first argument to the sites_return function would be the jqXHR Object. Instead of complete try using success.
But still this may not work as it seems that there is a parsing error (mentioned in the return value of sites_return function called from oncomplete). Therefore, you would first need to check your json string.
To Validate JSON, you can use http://jsonlint.com/
I think that the problem is that your server is not behaving the way jQuery expects it to. The JSONP "protocol" is not very stable, but generally what's supposed to happen is that the site should look for the "callback" parameter and use that as the function name when it builds the JSONP response. It looks as if your server always uses the function name "jsonp_callback".
It might work to tell jQuery that your callback is "jsonp_callback" directly:
$.ajax({
type: "GET",
url: wsUrl,
data: {},
dataType: "jsonp",
complete: sites_return,
crossDomain: true,
jsonpCallback: "jsonp_callback"
});
Not 100% sure however.
If you don't have the ability to change the JSONP function wrapper that the remote server returns, jQuery's $.ajax() may be overkill here. Ultimately, all you're doing is injecting a script reference to wsUrl, which makes a call to jsonp_callback with a JavaScript object literal as its input parameter.
You could just as easily do something like this and avoid the confusion around the callback naming/syntax:
$.getScript(wsUrl);
function jsonp_callback(response) {
// Access the array here via response.listEntries
}
Related
I'm quite new to JavaScript/jQuery so please bear with. I have been trying to store the resulting JSON after an ajax request so I can use the login info from it later in my program. I get an error stating that "Data" is undefined. Here is the problematic code:
function LOGIN(){
$.ajax({
url: 'https://.......&JSONP=Data&.........',
success: function Success(){
var SessionData = Data();
(FunctionThatParsesJSON);
}
})
}
I have checked the URL manually and it works fine (including) being wrapped in the "Data" function. From what I have found online, this may be something to do with ajax been asynchronous. Can anyone suggest a way of storing the JSON so that I can use it later?
Try something like the following;
function LOGIN(){
$.ajax({
url: 'https://.......&JSONP=Data&.........',
success: function Success(data){
functionToProcessData(data)
})
}
When making your ajax call, you can handle the response given by assigning a parameter to the function. In the case above, I have passed the 'data' parameter to the success function allowing me to then use it in further functions (as demonstrated by 'functionToProcessData(data)'.
The response from ajax call is captured in success handler, in this case 'data'.
Check below code:
success: function(data){
var SessionData = data.VariableName;
// Here goes the remaining code.
}
})
Since people ask about explanation, thus putting few words:
When we do $.ajax, javascript does the async ajax call to the URL to fetch the data from server. We can provide callback function to the "success" property of the $.ajax. When your ajax request completed successfully, it will invoke registered success callback function. The first parameter to this function will be data came from server as response to your request.
success: function ( data ) {
console.log( data );
},
Hope this helps.
Internally everything uses promises. You can explore more on promises:
https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Promise
Apparently you are using JSONP, so your code should look like this:
$.ajax({
url: 'https://.......&JSONP=Data&.........',
dataType:"jsonp",
success: function (data){
(no need to parse data);
}
});
Another option:
$.ajax({
url: 'https://.......&JSONP=Data&.........',
dataType:"jsonp"
})
.done(function (data){
(no need to parse data);
});
See the documentation and examples for more details.
success: function (data, textStatus, jqXHR){
these are the arguments which get passed to the success function. data would be the json returned.
My question regards the $.ajax() jQuery method. I can't get the success parameter in $.ajax() to work.
This works:
$.ajax({
type: 'POST',
url: "/getCodes.php?codes=billingCodes&parent="+$('#wClient').val(),
dataType: 'json',
success: window.alert("inside aJax statement")
});
This does not:
$.ajax({
type: 'POST',
url: "/getCodes.php?codes=billingCodes&parent="+$('#wClient').val(),
dataType: 'json',
success: function(){
window.alert("inside aJax statement");
}
});
In the first case, I get a JavaScript alert window that lets me know the $.ajax() I called is working. All that is changed in the second block of code is I put the window.alert() inside a function() { window.alert(); }.
The point of this is to verify that the $.ajax is running so I can put some actual useful code in the function(){} when the $.ajax runs successfully.
In your second example nothing will happen unless you get a successful call back from the server. Add an error callback as many here have suggested to see that indeed the ajax request is working but the server is not currently sending a valid response.
$.ajax({
type: "POST",
url: "/getCodes.php?codes=billingCodes&parent="+$('#wClient').val(),
dataType:"json",
success: function(response){
alert(response);
},
error: function(jqXHR, textStatus, errorThrown){
alert('error');
}
});
helpful Link in tracking down errors.
Your first example does nothing whatsoever to prove that the ajax call has worked. All it does is prove that the ajax function was reached, because the values of the properties in the anonymous object you're passing into the ajax function are evaluated before the function is called.
Your first example is basically the same as this:
// THIS IS NOT A CORRECTION, IT'S AN ILLUSTRATION OF WHY THE FIRST EXAMPLE
// FROM THE OP IS WRONG
var alertResult = window.alert("inside aJax statement");
$.ajax({
type: 'POST',
url: "/getCodes.php?codes=billingCodes&parent=" + $('#wClient').val(),
dataType: 'json',
success: alertResult
})
E.g., first the alert is called and displayed, then the ajax call occurs with success referencing the return value from alert (which is probably undefined).
Your second example is correct. If you're not seeing the alert in your second example, it means that the ajax call is not completing successfully. Add an error callback to see why.
In first case window.alert is executed immidiatly when you run $.ajax
In second it run only when you receive answer from server, so I suspect that something wrong in you ajax request
You may want to try and use a promise:
var promise = $.ajax({
type: 'POST',
url: "/getCodes.php?codes=billingCodes&parent="+$('#wClient').val(),
dataType: 'json'
});
promise.fail( function() {
window.alert("Fail!");
});
promise.done( function() {
window.alert("Success!");
});
What this does is saves the ajax call to a variable, and then assigns additional functionality for each of the return states. Make sure that the data type you are returning is actually json, though, or you may see strange behavior!
Note that js is single-threaded; the reason your first example works is because it actually executes the code next 'success' and stores the result. In this case there is nothing to store; it just pops an alert window. That means that the ajax call is leaving the client after the alert is fired: use the developer tools on Chrome or equivalent to see this.
By putting a function there, you assign it to do something when the ajax call returns much later in the thread (or, more precisely, in a new thread started when the response comes back).
I think that you do it right, but your request does not succeeds. Try add also error handler:
error: function(){alert("Error");};
I guess that dataType does not match or something like that.
It is 100% your second example is correct. Why it does nothing? Maybe because there is no success in the ajax call.
Add "error" handler and check waht does your ajax call return with the browsers' developer tool -> Network -> XHR . This really helps in handling of broken / incorrect ajax requests
I have a simple ajax call like this:
$.ajax({
url: u, type: "POST", dataType: "json",
data: data,
success: function (d) { response($.map(d, function (o) { return { label: o.Text, value: o.Text, id: o.Id} })); }
});
It is part of an tb autocomplete that does not work on only one view.
The reason it does not work is that instead of json, it makes jsonp request (by sniffing I saw that it calls passed url with ?callback=jQueryxxxxxxxxx), and success function is never called because jquery packs it into anonymous function whose name is passed in callback argument, and server returns standard json (I don't want to use jsonp as it is POST request and NOT cross-domain request). I checked, both current view url and this u for ajax url argument are on http://localhost:8080/myapp/areax/..., so I don't see why jQuery makes JSONP request here.
EDIT:
View on which this does not work has url request is made is like this:
http://hostname:8080/AreaName/Report/ViewReport
and u parameter of ajax is like /AreaName/MyAutoComplete/Search, so complete url to which autocomplete is made is like
http://hostname:8080/AreaName/MyAutoComplete/Search?callback=jQuery151013129048690121925_1327065146844
Server's response looks like this:
[{"Id":2,"Text":"001"},{"Id":7,"Text":"002"}]
I know it is not jsonp, for that it should be
<script>
jQuery151013129048690121925_1327065146844([{"Id":2,"Text":"001"},{"Id":7,"Text":"002"}]);
</script>
But I want to make normal json request, not jsonp.
UPDATE
Weirdest thing of all (I'm starting to think it is a bug in jQUery v1.5.1 which is used on project) is that when I remove dataType: "json", it makes a normal json request :)
So, instead of how to make json request, now I will accept an explanation to why this works as expected (and the one with dataType:"json" does not):
$.ajax({
url: u, type: "POST",
data: data,
success: function (d) { response($.map(d, function (o) { return { label: o.Text, value: o.Text, id: o.Id} })); }
});
From the bug here : http://bugs.jquery.com/ticket/8118
You are probably using jquery-validation plugin. Jquery-validation plugin is not compatible with jQuery 1.5 and the conflict causes the kind of issue you are having here.
If the problem is not specifically due to jquery-validation plugin, check if you have any other jquery plugin that might not be compatible with jQuery 1.5
I'm looking for a way to return a single JSON/JSONP string from a cross-domain "AJAX" request. Rather than request the string and have JQuery return it as a generic object automatically, I want to get a hold of the string BEFORE that conversion happens. The goal here is to parse it myself so I can turn it straight into new objects of a certain type (e.g. a Person object).
So, just to make this clear, I don't want any string-to-generic-object conversion going on behind the scenes and this must work using a different domain.
Here's a non-working example of what I would like to do:
$.ajax({
type: 'GET',
url: 'http://www.someOtherDomain.com/GetPerson',
dataType: 'text',
success: parseToPerson
});
function parseToPerson( textToParse ) {
// I think I can do this part, I just want to get it working up to this point
}
I'm perfectly happy if JQuery isn't involved in the solution, as long as it works. I would prefer to use JQuery, though. From what I've read, the javascript techniques used to get JSONP data (dynamically creating a script element) would probably work, but I can't seem to get that to work for me. I control the domain that I am requesting data from and I can get the data if I change the dataType in the AJAX call to 'JSONP', so I know that is working.
If your data is being retrieved from another domain, you will need to use JSONP (there are other options, but JSONP is by far the easiest if you control the service). The jQuery call will look like this:
$.ajax({
// type: 'GET', --> this is the default, you don't need this line
url: 'http://www.someOtherDomain.com/GetPerson',
dataType: 'jsonp',
success: parseToPerson
});
The actual request that goes to your service will be http://www.someOtherDomain.com/GetPerson?callback=arbitrary_function_name. On the service side, you will need to return data like this:
arbitrary_function_name("the string (or JSON data) that I want to return");
So you'll need to inspect the querystring parameters, get the value of the callback parameter, and echo it out as if you're calling a Javascript function with that name (which you are), passing in the value you want to provide through the service. Your success function will then get called with the data your service provided.
If you're deserializing the returned data into a Javascript object, you might be better off returning JSON data than a string, so the data your service returns might look like this:
arbitrary_function_name({
"name":"Bob Person",
"age":27,
"etc":"More data"
});
That way you don't have to worry about parsing the string - it'll already be in a Javascript object that's easy to use to initialize your object.
Not sure how this will work in conjuction with jsonp, but maybe converters is what you're looking for?
$.ajax(url, {
dataType: "person",
converters: {
"text person": function(textValue) {
return parseToPerson(textValue);
}
}
});
I want to get live currency rates from an external source, so I found this great webservice:
Currency Convertor
This service is working like a charm, the only downside is that it does not provide JSONP results, only XML. Therefore we have a cross browser problem while trying to consume this webservice using jQuery $.ajax().
So I found Yahoo Query Language which returns results as JSONP and also mangae to consume other webservices and return me the results. This is also working, here is an example URL:
http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20xml%20where%20url%3D'http%3A%2F%2Fwww.webservicex.net%2FCurrencyConvertor.asmx%2FConversionRate%3FFromCurrency%3DNOK%26ToCurrency%3DEUR'&format=json&diagnostics=true&callback=cbfunc
This URL return JSONP result and is working like a charm, but the problem appears when I use this in my code:
$.ajax({
type: "GET",
url: urlToWebservice,
contentType: "application/json; charset=utf-8",
dataType: "jsonp",
success: function(data) {
$("#status").html("OK: " + data.text);
},
error: function(xhr, textStatus, errorThrown) {
$("#status").html("Unavailable: " + textStatus);
}
});
When I try to run this code nothing happens, and I can see this error message in my Firebug javascript debugger:
cbfunc is not defined
cbfunc is the name of the container which surrounds the JSON response, but why does it say not defined?
EDIT:
This is my new code, but I still get the cbfunc is not defined
$.ajax({
url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20xml%20where%20url%3D'http%3A%2F%2Fwww.webservicex.net%2FCurrencyConvertor.asmx%2FConversionRate%3FFromCurrency%3DNOK%26ToCurrency%3DEUR'&format=json&callback=cbfunc",
dataType: 'jsonp',
jsonp: 'callback',
jsonpCallback: 'cbfunc'
});
function cbfunc(data) {
alert("OK");
}
And the "OK" message is never fired...
If available, use the jsonpCallback parameter in the call to $.ajax like:
jsonpCallback: "cbfunc",
Its description, from the jQuery API docs reads:
Specify the callback function name for a jsonp request. This value will be used instead of the random name automatically generated by jQuery.
The docs later go on to say:
It is preferable to let jQuery generate a unique name as it'll make it easier to manage the requests and provide callbacks and error handling. You may want to specify the callback when you want to enable better browser caching of GET requests.
However it is not advised to make use of this "preferable" behaviour when making use of YQL. Precisely why that approach is not ideal might make this answer far too verbose, so here is a link (from the YQL blog) detailing the problems with jQuery's preferred approach, making use of jsonpCallback and so on: Avoiding rate limits and getting banned in YQL and Pipes: Caching is your friend
You should let jQuery handle the callback by changing urlToWebservice to end in callback=?
The reason it's not working is because by specifying callback=cbfunc in the querystring generates a URL of the type:
http://query.yahooapis.com/...&callback=cbfunc&callback=jsonp1277417828303
Stripped out all uninteresting parts, but the URL contains two callback parameters. One of them is managed by jQuery, and the other one not. YQL only looks at the first callback parameter and returns a response wrapped around that.
cbfunc({"query":{...}});
However, there is no function named cbfunc in your script, so that's why you are getting the undefined error. jQuery created an implicit function named jsonp1277417828303 in the above example, and the response from YQL should instead have been:
jsonp1277417828303({"query":{...}});
for jQuery to act upon it, and return the response to your success callback which it never got to do.
So, as #SLaks suggested, remove the &callback=cbfuncfrom your URL, or replace it with &callback=? to let jQuery handle things.
See a working example.
You definitely should give jQuery-JSONP a try: http://code.google.com/p/jquery-jsonp/
Simplifies everything :)