jQuery Cross Domain Request to get JSON Response without Callback - ajax

I am trying to retrieve a JSON from this URL
http://www.iheartquotes.com/api/v1/random?format=json
via jQuery. I know the solution is JSONP, but since I have no control over the response text of the service or to wrap it in my own callback function, my aim is to somehow retrieve the response of the above URL using client-end scripts.
I have tried almost all the methods suggested from several answers from StackOverflow.
These are the code blocks I have tried and the response's I've got.
1 . A direct call which returned the expected Access-Control-Allow-Origin error
$.getJSON("http://www.iheartquotes.com/api/v1/random?format=json",
function(data) {
alert(data);
});
Response:
XMLHttpRequest cannot load
=1376682146029">http://www.iheartquotes.com/api/v1/random?format=json&=1376682146029.
Origin http://stackoverflow.com is not allowed by
Access-Control-Allow-Origin.
2 . The above code with the callback parameter added:
$.getJSON("http://www.iheartquotes.com/api/v1/random?format=json&callback=?",
function(data) {
alert(data);
});
Response:
Uncaught SyntaxError: Unexpected token :
Please note that when I click on the error, it takes me to the expected JSON response.
{"json_class":"Fortune","tags":["simpsons_homer"],"quote":"Holy Moly! The bastard's rich!\n\n\t\t-- Homer Simpson\n\t\t Oh Brother, Where Art Thou?","link":"http://iheartquotes.com/fortune/show/5501","source":"simpsons_homer"}
This is also expected as there is no callback function defined in the response.
3 . Through jQuery's Ajax method
$.ajax({
type: "GET",
dataType: "jsonp",
url: "http://www.iheartquotes.com/api/v1/random?format=json",
success: function(data){
alert(data);
},
});
Response:
Uncaught SyntaxError: Unexpected token :
Adding the callback parameter to the above function doesn't change the response.
Any help or pointers from the experts to retrieve the JSON from the URL? I am testing this from the Chrome Dev Tools. I know I could call the service from the server-end code and then send it across to the client-end. But I want to see if this can be done through jQuery alone from the client-end.
EDIT:
Based on Kevin B's comment:
Got the expected output via YQL using jQuery's Ajax. But my question remains the same. Is there a native way to do it via jQuery as YQL is still a dependency?
// Using YQL and JSONP
$.ajax({
url: "http://query.yahooapis.com/v1/public/yql",
// the name of the callback parameter, as specified by the YQL service
jsonp: "callback",
// tell jQuery we're expecting JSONP
dataType: "jsonp",
// tell YQL what we want and that we want JSON
data: {
q: "select * from json where url=\"http://www.iheartquotes.com/api/v1/random?format=json\"",
format: "json"
},
// work with the response
success: function( response ) {
console.log( response.query.results.json ); // server response
}
});
This gives the expected response.

This won't work in all browsers, but depending on which version of JQuery you're using try:
$.support.cors = true;
Obviously this also depends on the headers of the server response.

Related

javascript: how to make AJAX call based on the avaiable cURL request

Currently in my web app project, I need to parse the content of a web page, and after some searching, I found that Mercury Web Parser API is quite suitable for me.
And I have some experience with such kind of third party APIs, generally speaking I can get my desired result.
But for this API, I can't find documentation about the API usage on the official website.
Based on the my study, it provide two methods:
first is cURL as following:
curl -H "x-api-key: myapikey" "https://mercury.postlight.com/parser?url=https://trackchanges.postlight.com/building-awesome-cms-f034344d8ed"
the myapikey is the API key I get from the website. Then I can get the result in JSON format, which is the main content of the web page specified by the url parameter. It works well for me, I mean the cURL method.
And on the website, it said that the second method is HTTP call, which is just what I need:
GET https://mercury.postlight.com/parser?url=https://trackchanges.postlight.com/building-awesome-cms-f034344d8ed
Content-Type: application/json
x-api-key: myapikey
So based on my understanding, I use jquery AJAX method to do this as following:
var newurl = "https://mercury.postlight.com/parser?url=http://www.businessinsider.com/joel-spolsky-stack-exchange-interview-2016-12&x-api-key=myapikey"
$.ajax({
url: newurl,
dataType: "jsonp",
success: function(data){
console.log(data.title);
}
})
here I made JSONP request because of the Cross origin issue.
But now I face 401 error message (401 Unauthorized. The request has not been applied because it lacks valid authentication credentials for the target resource)
For now my guess is that the apikey is not correctly passed to server. So based on the cURL's successful call, can I get the correct format for AJAX call?
Update:
Based on the following answers ,I tried to set the request header as following:
$.ajax({
url: newurl,
dataType: "jsonp",
beforeSend: function(xhr){
console.log(apiKey);
xhr.setRequestHeader('x-api-key', apiKey);
},
/*
headers: {
"x-api-key": "M1USTPmJMiRjtbjFNkNap9Z8M5XBb1aEQVXoxS5I",
"contentType": 'application/json'
},
*/
success: function(data){
console.log("debugging")
console.log(data.title);
},
error: function (error) {
console.log(error)
}
})
I tried both beforeSend and headers. But still can't work and get the following trackback error message:
send # jquery.js:8698
ajax # jquery.js:8166
addNewArticle # topcontroller.js:18
fn # VM783:4
e # angular.js:281
$eval # angular.js:147
$apply # angular.js:147
(anonymous) # angular.js:281
dispatch # jquery.js:4435
elemData.handle # jquery.js:4121
And for the last send function, still 401 error.
But the ajax error handling part shows that the readyState:4 and status: 404 result. So what's going here.
For your question, the curl request is sending a header which you have attached as part of the query string in your $.ajax request.
Try the following instead (using beforeSend + xhr) :
// broke this string down so you don't have to scroll
var newurl = "https://mercury.postlight.com/parser?" +
"url=http://www.businessinsider.com/" +
"joel-spolsky-stack-exchange-interview-2016-12";
// set your api key
var apiKey = "<your api key>";
$.ajax({
url: newurl,
dataType: "json",
beforeSend: function(xhr){xhr.setRequestHeader('x-api-key', apiKey);},
success: function(data){
console.log(data.title);
}
})

Cross domain Ajax call from HTML page (can't use any proxy)

I was trying to get some information from another server using ajax post call as .
$.ajax({
type: 'POST',
url: testURL,
data: data,
//dataType: 'jsonp',
dataType: "script",
success: function (data) {
alert("Successfully posted (Test) : " + data);
},
error: function (ts) {
alert("Inside Error : " + ts.responseText);
}
});
Here testURL is the URL where i am posting the data (Cross domain requests are only possible if datatype is either jsonp or script), and it suppose to return text/html data back (what fiddler says will be the return type for the data).
I am not sure if i can use any proxy as pages are normal HTML pages.
Isn't there any way to get the [data] as text (as for now success expecting JASONP data and alert("Successfully posted (Test) : " + data); only showing data as undefined). I can't make any changes to API or whatever it is on the remote Server.
Thanks for the help in advance.
Regards
Without a proxy you cannot do it. If that is in a windows box, you can create a COM object to make the call to that server and from your JavaScript you call that COM.
UPDATE:
Well it seems you can with JSONP
jsonp with jquery

Accessing stackoverflow API with jsonp gives unexpected result

I am trying to access the Stackoverflow API with jsonp as datatype by doing this:
$(document).ready(function(){
$.ajax({
url: 'http://api.stackoverflow.com/1.1/tags/php/top-answerers/month',
dataType: 'jsonp',
});
});
And once I reload, I get the following in the console:
"Uncaught SyntaxError: Unexpected token :"
What am I doing wrong here?
Right now the application is returning Content-Type: application/json.
You can fix this by overriding the callback function name to jsonp which will tell the server to return Content-Type: application/javascript instead:
$(document).ready(function () {
$.ajax({
url: 'http://api.stackoverflow.com/1.1/tags/php/top-answerers/month',
dataType: 'jsonp',
jsonp: 'jsonp',
success: function (data) {
alert(data.top_users.length + ' users retrieved.');
}
});
});
Info on jsonp ajax setting:
jsonpString
Override the callback function name in a jsonp request. This value
will be used instead of 'callback' in the 'callback=?' part of the
query string in the url. So {jsonp:'onJSONPLoad'} would result in
'onJSONPLoad=?' passed to the server. As of jQuery 1.5, setting the
jsonp option to false prevents jQuery from adding the "?callback"
string to the URL or attempting to use "=?" for transformation. In
this case, you should also explicitly set the jsonpCallback setting.
For example, { jsonp: false, jsonpCallback: "callbackName" }
From https://api.stackexchange.com/docs
All API responses are JSON, we do support JSONP with the callback query parameter. Every response in the API is returned in a common "wrapper" object, for easier and more consistent parsing.
So you should use dataType: 'json' rather than jsonp.
You should also upgrade to the 2.1 API, the 1.x API has been deprecated for 6 months.

POST request to Picasa API

I'v been struggling with POST on the Picasa API.
Here's code:
$.ajax({
type: "POST",
url: 'https://picasaweb.google.com/data/feed/api/user/' + uid + '/albumid/' + album_id + '/photoid/' + photo_id,
crossDomain: true,
data: { content: content },
success: function() { alert("Success"); },
error: function() { alert('Failed!'); }
});
I've already retrieved some information via GET without problems.
Now comes the fun part, when I try to test the service with Google this error occurs:
XMLHttpRequest cannot load
https://picasaweb.google.com/data/feed/api/user/userid/albumid/albumid/photoid/photoid?content=foo%bar.
Origin http://localhost:3000 is not allowed by
Access-Control-Allow-Origin
.
And when I try in Firefox the request header method is changed to OPTIONS and status is 204: no content.
Also, I've tried to change datatype to jsonp but then HTTP method changes to GET and it retrieves information about the picture.
Access-Control-Allow-Origin is coming because your are making a ajax call to a server which is not same as your current domain.
Read more here
jsonp will not help for POST request because you can only make GET request with jsonp.
IMHO you should try to make the POST request from server side instead of client side script.

why Ajax get Request failed

The response of my request is a java script code. When I put the url in browser, I can see the whole generated java script code on the page. Format of url passed to $.ajax is as below:
http://localhost:8080/vi-api/viapi?action=tag&projectId=45&tagId=345
When I put the above URL I can see the request is successful. Now, I am using below Ajax request for this url using jQuery.
var finalUrl = "http://localhost:8080/vi-api/viapi?action=tag&projectId=45&tagId=345";
var req = $.ajax({
type:"GET",
url:finalUrl,
type:"script",
data:"",
success: function(html){
alert('Requese sucessful.');
},
complete:function(jqXHR, textStatus) {
alert("request complete "+textStatus);
},
error: function(xhr, textStatus, errorThrown){
alert('request failed->'+textStatus);
}
});
Question 1:This gives the alert "request failed error'. Why this is so ?
Question 2:Is there any way to return success/failure code in above process?
In:
$.ajax({
type:"GET",
url:finalUrl,
type:"script",
(...)
You have two times the 'type' key in your object. So I think only the second one is taken ('script'). Obviously 'script' is not a valid HTTP method (as HEAD,GET,PUT,POST, etc). The keyword your were looking at for 'script' is maybe dataType which may be one of xml, json, jsonp, text, script, or html.
Do not forget to look at jsonp, it's usually a nice way to return a script content and to call it.
I am not sure why, but I can give your some tips how to debug or find out issues:
1) install fiddler to look at HTTP request.
2) type:"script", why the type is script? try to use "text/html".
3) use complete(jqXHR, textStatus) you can look at HTTP status. more info about $.ajax
var finalUrl=http://localhost:8080/vi-api/viapi?action=tag&projectId=45&tagId=345;
is pretty invalid javascript. You probably meant passing the url as a string:
var finalUrl = 'http://localhost:8080/vi-api/viapi?action=tag&projectId=45&tagId=345';

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