Invalid Label Error with JSON request - javascript

I've read about this a lot and I just can't figure it out. It has nothing to do with MY code, it has to do with the feed or something because if I swap it with a Twitter feed it returns an Object object which is perfect.
$.getJSON('http://rockbottom.nozzlmedia.com:8000/api/portland/?count=1&callback=?',function(json){
console.log(json)
});
And i get an "invalid label" error. Any ideas?
Also, a side note, I've tried the AJAX method as well:
$.ajax({
url: 'http://rockbottom.nozzlmedia.com:8000/api/portland/',
dataType: 'jsonp',
data: 'count=1',
success: function(msg){
console.log(msg)
}
});
and both give the same exact error, and both work fine with Flickr and Twitter examples, so it must be something to do with the feed, but I dont have access to the feed, but I could ask them to fix something IF it's their issue.

Make sure that the server side can handle the JSONP request properly. See here for example.
Edit: It seems that the server doesn't wrap the returned JSON object with the callback function name. The server should return:
callback( { json here } )
and not
{ json here }

That URL looks like it's expecting you to provide a JSONP callback (from the callback=? bit). That's probably the problem; it's returning Javascript rather than JSON (because that's how JSONP works). See the $.ajax docs for more about using JSONP services.

The returned content has unescaped double-quotes in one of the strings. It's invalid JSON:
..."full_content":"just voted "with Mandy " on...

Related

Uncaught SyntaxError: Unexpected token : - data still coming through

I'm very new to JSON and JSONP.
I've read through each of the posts that are recommend by the SO search for this error, but I can't seem to get a handle on it.
I have the following code to grab data from an EXTERNAL website:
$.ajax({
url: "https://url.com/authenticate?login=test&apiKey=test",
dataType: 'jsonp',
success:function(json){
console.log("login successful");
}
});
When I load the page, I get:
Uncaught SyntaxError: Unexpected token :
and when I click on the error in Chrome, I see
{"Status":{"Code":"2","Message":"Authentication Succeeded","Success":"true"}}
with a little red x after "true"})
From this, it seems as though I have succeeded in logging in, but I'm doing something else wrong because my console.log("login successful"); never fires. What am I doing wrong?
P.S.
I've tried dataType: 'json' but I get the No 'Access-Control-Allow-Origin' header is present as I'm on a different server, so I went back to jsonP as this is cross-domain.
I've also tried the above url as url: "https://url.com/authenticate?login=test&apiKey=test&callback=?", as I've read I need a callback, but I don't really understand what the functionality of callback is and either way, the error that gets returned (whether &callback=? is in there or not) is:
authenticateUser?login=test&apiKey=test&callback=jQuery111107732549801003188_1423867185396…:1 Uncaught SyntaxError: Unexpected token :
so it's adding the callback in either way....
Also, from the API I'm trying to access:
"this uses the REST protocol, and provides data structured as XML or JSON"
This is not a duplicate of the linked post as the information in the linked post does a great job of explaining what JSONP is, but doesn't answer my specific question regarding why I get data back (so my call is successful,) but why I still get an error and cause my script to stop.
The API you're sending the AJAX request doesn't implement JSONP. It ignores the callback= parameter, and just returns ordinary JSON. But when the browser tries to process this as JSONP, it gets a syntax error because it's not properly formatted. JSONP is a JSON object wrapped in a call to the specified callback function, e.g. it should be sending back:
jQuery111107732549801003188_1423867185396({...});
where {...} is the JSON object you're trying to retrieve. But it's just returning {...}.
You should implement this using a PHP script on your own server. It can be as simple as this:
<?php
$username = urlencode($_POST['user']);
readfile("https://url.com/authenticate?login=$username&apiKey=test");
Then your AJAX call would be:
$.ajax({
url: "yourscript.php",
type: "post",
dataType: "json",
data: { user: "test" },
success: function(json) {
console.log("login successful");
}
});

200/'parsererror' with jquery on ajax post to a https

I've read loads of other questions about this argument, but none could solve my problem.
I make a call to a php page in this way.
$.ajax({
url: 'https://mydomain/page.php',
type: "POST",
data: {
"arg1": arg1,
"arg2": arg2
},
success: function(data, textStatus, xhr) {
//do stuff
},
error: function(xhr, textStatus) {
alert("doLogin\n- readyState: "+xhr.readyState+"\n- status: "+xhr.status);
}
});
Now, if I put this stuff on the same server as the php it works fine. Troubles start when I launch it from localhost.
In that case I receive the following in the xhr:
readyState=0, status=0, statusText="error".
Reading some answers on the topic it seems to be because of a same-origin restriction, so I added a few parameters to the call. notably:
dataType:"jsonp",
crossDomain: true,
Apparently this works better, cause now I receive readyState=4, status=200, statusText="success". Trouble is, textStatus="parsererror". I also tried other things as jsonpCallback, cache, async, jsonp in many configurations with no luck.
Now, I receive no data back, cause this call will only give me a cookie that I need.
My question is: am I doing things correctly, for starters? In both cases, what is the reason of such an error? Does the fact that I call a 'https'/POST change something, rather than a plain http/GET?
Second question is, later on I will have to call some webservices through soap requests, which will return data in xml. Will using this same technique work (assuming jQuery doc is fine and I can write dataType:"jsonp xml" to have it converted on the fly (and assuming it is the right technique as well))? I assume it won't be, as jsonp expects something on the line of callbackFN({...}) rather than an xml, right?
If none of this is correct, what would the correct way to proceed be? I can't touch the server, thus I am limited to client side.
If you set dataType as JSONP, you can only get data as JSON.
So if the url (https://mydomain/page.php) doesn't response a JSON object, you will get parsing error, because it tries to parse it and fails.
JSONP is for JSON format data only! So if you receive a parseerror this means that the output of your PHP might not be well-formed JSON
And no, it is not easily possible to have XML as response to a JSONP call ..

Getting 'data is null' on a Twitter API call but displays data in browser

I'm trying to display the follow count of a twitter account, but when I hook into the API using this code:
$.getJSON("https://api.twitter.com/1/users/show.json?screen_name=uswitchTech&include_entities=true", function(data) {
console.log(data);
if (!data.error) {
$("#followers").html(data.followers_count);
}
});
I get a 200 ok report but with Data is null message.
But if I download the json file to my local machine and change the getJSON call accordingly, it works straight away.
Has anyone got any ideas on what could be causing this?
Thanks
Also just to add, if I put the Twitter API url into my browser it displays all the data, which makes it even weirder.
Maybe the problem lies with jsonP, since you are calling a remote server and you must specify you should use jsonP. Have you tried adding callback=? as a parameter
$.getJSON("https://api.twitter.com/1/users/show.json?screen_name=uswitchTech&include_entities=true&callback=?", function(data) {
if (!data.error) {
$("#followers").html(data.followers_count);
}
});
Taken from jQuery docs
JSONP
If the URL includes the string "callback=?" (or similar, as
defined by the server-side API), the request is treated as JSONP
instead. See the discussion of the jsonp data type in $.ajax() for
more details.
$.ajax({
url: 'https://api.twitter.com/1/users/show.json?screen_name=uswitchTech&include_entities=true',
dataType: 'jsonp',
success: function(data){
console.log(data.followers_count);
}
});

Return String from Cross-domain AJAX Request

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);
}
}
});

jQuery + JSONP + Yahoo Query Language

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 :)

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