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

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 ..

Related

How to get JSON Object from URL

I'm very new to web development.
When I input this link
https://api.locu.com/v1_0/venue/search/?name=jimmy%20johns&api_key=b1f51f4ae241770f72fca5924d045733c4135412
into my browser, I can see the JSON object.
What do I need to do so can I use this JSON object in my javascript? I've tried using JQuery's $.getJSON with no luck.
EDIT
Using JSONP worked! Appending &jsonp=readJSON&?callback=? to the URL gave me back the JSON I wanted. Thank you for all the informative answers.
$.getJSON( "https://api.locu.com/v1_0/venue/search/?name=jimmy%20johns&api_key=b1f51f4ae241770f72fca5924d045733c4135412&jsonp=readJSON&?callback=?", function() {
console.log( "success" );
})
function readJSON(response){
console.log (response);
}
The question is, is this domain (api.locu.com) the same from where you serve your files? I suppose it isn't. In this case, you have two options:
Your backend can proxy the request from this site
You have to use a JSONP object if it's supported by the API
I'm no clear about your question, but I think you can use a call ajax, something like:
$.ajax({
url: "https://api.locu.com/v1_0/venue/search/?name=jimmy%20johns&api_key=b1f51f4ae241770f72fca5924d045733c4135412",
type: 'get',
cache: false,
success: function (response) {
console.log(response);
}
});
This should get the concept across if you are using JQuery... but you can use just about anything.
var url = "https://api.locu.com/v1_0/venue/search/?name=jimmy%20johns&api_key=b1f51f4ae241770f72fca5924d045733c4135412";
var result;
var settings = {
success: function(data){
result = data;
//do anything else related to this data here as you need it fetched, and is not linear.
}
}
$.ajax(url, settings);
Now, I noticed you used getJSON, which is pretty much the exact same. I did not however see you use a success function, so if you did your way, have you tried:
$.getJSON(url, function(data){
result = data;
});
I may be mistaken, but you say: "With no luck" so i have a limited understanding as to what you tried with $.getJSON
Not directly from inside a web browser, no. You would need to use a proxy: another server that makes this request in your behalf and then gives you the result.
Why not?
Web browsers are pretty tight on security. One of the strategies for protecting users from malicious activity is restricting the domains your Javascript can make HTTP requests to.
An HTTP request from your domain (the origin) to another domain is called a cross-origin request. These are forbidden by default, and you won't be able to read the response body, unless the received HTTP response includes the header Access-Control-Allow-Origin.
How then?
By using a proxy as an intermediary. The proxy is not a web browser, it doesn't care about Access-Control-Allow-Origin, and will read the response anyway.
There are a number of proxies you can use. An easy one is YQL (the Yahoo Query Language). Here's an article on the topic, using jQuery: http://ajaxian.com/archives/using-yql-as-a-proxy-for-cross-domain-ajax

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");
}
});

How to get PHP page returned by a jQuery Ajax request

So I have to send some data to a php page, and it will return me another php page based on my data.
I send the data this way:
$(document).ready(function() {
$.ajax({
url: '//www.example.com/page.php',
type: "post",
dataType: 'jsonp',
data: { myvar:myvalue },
success: function(response) { console.log("success."); },
error: function(XMLHttpRequest, textStatus, errorThrown) { console.log("error."); },
complete: function() { console.log("complete."); }
});
});
It shows an alert saying jQuery180014405992737595236_1357861668479 was not called (numbers are copied from other question)
I think the reason is that it's expecting a json result from the page, when it's not.
In Chrome it says Uncaught SyntaxError: Unexpected token < referring to the returned php page, so I assume that my code isnt expecting that kind of file to be returned.
To sum up, this works, but that jQuery alert and the console error needs to be fixed, and I think the right way would be handling properly the returned result page.
I hope you guys can help me fix it that seems quite a simple task, but Im really new to this. Thanks
Removing the dataType: 'jsonp' or changing it to 'json' turns out on my script not being executed and getting the following error:
XMLHttpRequest cannot load http://www.example.com/page.php. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://myserver.com/myPage' is therefore not allowed access.
I think the reason is that it's expecting a json result from the page
It's expecting a JSONP response. (JSONP is not JSON). You said:
dataType: 'jsonp',
… which explicitly forces jQuery to treat the response as JSONP (and, as a side effect, GET).
the returned php page, so I assume that my code isnt expecting that kind of file to be returned.
The server shouldn't be returning a PHP page. It should be executing the PHP code and returning whatever that outputs. It looks like it is outputting HTML.
You need to either:
Not tell your script to expect JSONP. (Note that you'll probably then have to configure CORS on the server to deal with same origin issues) or
Change the PHP to return JSONP

JSONP Syntax Error

I'm writing a jQuery interface to use a couple of OData services created in SAP. The services is working ok, and are also being used by some other applications.
I've already searched and I'm mostly come across people who are saying it's a cross domain issue. The first thing I tried was to plain and simply do a cross domain ajax call:
$.ajax({
url : 'http://saphostname:8000/sap/opu/odata/sap/entityset/?$format=json',
crossDomain : true,
xhrFields {
withCredentials : true,
}
// .. success, statusCodes, whatever ..
})
The responses that came from this call were 200, and if I viewed the content in the developer tools I saw my json message as I would expect it to be in there, but none of my callback functions were being triggered.
Upon searching more, somebody suggested using $.getJSON(). This didn't work either. The error that kept coming back was 401, so I assumed it was a cross domain issue.
The last thing I stumbled upon was JSONP. The response is coming back with an OK status code, and once again if I view the body content I see my json string as I would expect it. The only problem is my browser says there is a syntax error in the response text.
All of my search results have brought up issues regarding cross domain requests, and errors resulting there-in. Maybe it is the issue, but because I'm getting the results back that I would expect in the responses, I'd have to assume that connectivity is no problem.
tl;dr: ajax cross-domain requests are successful but don't trigger callback functions and jsonp gives me a syntax error. I'm not sure where to keep looking.
You are trying to do a JSONP request to a JSON service. The way that the response is handled for a JSONP request is that it is executed, but executing a JSON response only evaluates it and discards it.
The crossDomain property only causes the request to act like a cross domain request, i.e. using JSONP, regardless if it's actually to a different domain or not.
You should specify dataType: 'json' in the properties, to keep it from using JSONP.
Alternatively, if the service also supports JSONP, you could change $format=json in the URL to $format=jsonp, and specify dataType: 'jsonp' in the properties.
Edit:
Another thing that you can try is to use a proxy that turns a JSONP request to a JSON request. I have set up such a proxy that you can use to test if you can get the right response:
$.get(
"http://jsonp.guffa.com/Proxy.ashx?url=" + escapeURIComponent("saphostname:8000/sap/opu/odata/sap/entityset/?$format=json"),
function(data) {
console.log(data);
},
"jsonp"
);
I already had a problem like this before and what helped me to solve the problem was using callbacks like these:
// Assign handlers immediately after making the request,
// and remember the jqXHR object for this request
var jqxhr = $.ajax( "example.php" )
.done(function() {
alert( "success" );
})
.fail(function() {
alert( "error" );
})
.always(function() {
alert( "complete" );
});
// Perform other work here ...
// Set another completion function for the request above
jqxhr.always(function() {
alert( "second complete" );
});
Now you can see which one is being triggered and debug the problem.

Invalid Label Error with JSON request

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...

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