This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
XmlHttpRequest error: Origin null is not allowed by Access-Control-Allow-Origin
XMLHttpRequest cannot load file://… Origin null is not allowed by Access-Control-Allow-Origin
I am trying to open my JSON file such as:
jQuery.getJSON('../data/json/en/nodesData.json',
function(data){
jQuery.each(data, function(){
//do something...
})
})
this yields the following error in Chrome:
XMLHttpRequest cannot load file:///C:/URL/data/json/en/nodesData.json. Origin null is not allowed by Access-Control-Allow-Origin
what's problem? How can I retrieve my json?
You really should be running a local server like Apache or IIS to run HTML/JavaScript code so you do not run into these restrictions.
You can start the browser up with the flag --allow-file-access-from-files which removes the restriction.
For security reasons, you cannot make AJAX calls to your local file system. Some browsers allow this, but others don't. Chrome has a flag that enables this, but it's off by default.
Take a look into Same Origin Policy.
You cannot load the file because technically it is located in another domain. You need to call it like localhost/<Path>/nodesData.json.
Related
This question already has answers here:
How does the 'Access-Control-Allow-Origin' header work?
(19 answers)
No 'Access-Control-Allow-Origin' header is present on the requested resource—when trying to get data from a REST API
(26 answers)
Closed 4 years ago.
Hi I'm new to javascript and API calls and I'm trying to make an API call using the following javascript code:
var url = 'https://labs.bible.org/api/?
passage=random&type=json&callback=myCallBackFcn';
var ourRequest = new XMLHttpRequest();
ourRequest.open('GET', url);
ourRequest.onload = function(){
console.log(ourRequest.responseText);
};
ourRequest.send();
When I refresh my page I get the following error:
Failed to load
https://labs.bible.org/api/?passage=random&type=json&callback=myCallBackFcn:
No 'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'null' is therefore not allowed access.
Can anyone help me with this? Also, can you explain exactly how to fix it?
You have a cross-origin issue, let's explain it.
Browser downloaded js file from example.com website, now js file wants to make ajax to xyz.org website, this is a cross-origin request and so the browser asks xyz.org "do you allow example.com to access your resources"? the browser knows the answer from 'Access-Control-Allow-Origin' Response header.
But xyz.org didn't send this header so the browser assumed xyz.org doesn't want anyone but him to access his resources so the browser just refuses your request.
Note that cross-origin request happens too when you access js file in a URL beginning with file:// and origin here is set to null because js isn't downloaded from any server yet origin null is different from xyz.org.
Solution: if you control xyz.org just make it add Access-Control-Allow-Origin to response headers, you can look the internet for value format for this header.
If it's a third party website you have to call its admins and if they refuse to add the header then you simply have no solution in pure js but hey only browsers respects this policy, if you make a desktop application then it doesn't care and an example of this is Postman the REST APIs tester.
This question already has answers here:
XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header
(11 answers)
Closed 3 years ago.
I'm unable to retrieve data from the Rescue Time API. I'm making a request in a JavaScript file using the jQuery get() method. Here is a look at the JavaScript related to the API GET request:
$.get('https://www.rescuetime.com/anapi/data?key=########################&format=json&restrict_kind=overview', function(data) {
// callback function code...
});
The "key=########################" is the paramater that includes my API key.
When running the script (either locally or on my personal domain), I receive a cross origin error:
XMLHttpRequest cannot load https://www.rescuetime.com/anapi/data?key=########################&format=json&restrict_kind=overview. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.
I understand that this is happening because i'm requesting content that is on a different domain than the one that is making the AJAX request. That being said, how do I get around this? I've read the CORS MDN documentation, but could not decode what actionable steps I need to follow in order to resolve this issue.
I need some actionable steps.
Set up a CORS proxy using the code from https://github.com/Rob--W/cors-anywhere/ or similar.
https://cors-anywhere.herokuapp.com/ is a public instance running that code, and the way you could use it is by changing your existing code to this:
$.get('https://cors-anywhere.herokuapp.com/https://www.rescuetime.com/anapi/data?key=########################&format=json&restrict_kind=overview', function(data) {
// callback function code...
});
Be aware though that if you do that, your key would potentially be exposed to the operator of that https://cors-anywhere.herokuapp.com/ instance. So if that’s a concern then don’t try it, and instead set up your own proxy at https://some.url.for.your.proxy and change your code to:
$.get('https://some.url.for.your.proxy/https://www.rescuetime.com/anapi/data?key=########################&format=json&restrict_kind=overview', function(data) {
// callback function code...
});
Either way the result will be that your request gets sent through the specified CORS proxy, which forwards the request to the https://www.rescuetime.com/anapi/data… endpoint and then receives the response. The proxy backend then adds the Access-Control-Allow-Origin header to the response and finally passes that back to your requesting frontend code.
Your browser then allows your frontend code to access the response, because that response with the Access-Control-Allow-Origin response header is what the browser sees. Otherwise, if the response lacks Access-Control-Allow-Origin, browsers won’t let your code access it.
A CORS proxy like that is the only option if you want to make the request from frontend JavaScript code running in a browser, and want to consume the response from that frontend code. Otherwise, without the use of such a proxy, browsers will block your code from accessing the response—because the https://www.rescuetime.com/anapi/data… API endpoint doesn’t itself send the necessary Access-Control-Allow-Origin response header.
Your only other option otherwise is to not make the request from your frontend code but instead make the request from whatever backend server-side code you’re running. In that case there’s no browser in the middle enforcing cross-origin restrictions on the request.
This question already has answers here:
Jquery: Running AJAX locally without a webserver
(7 answers)
Closed 6 years ago.
This is extremely simple,
In a HTML file, inside of a <script> tag, I have
$.getScript("alert.js");
It doesn't work. alert.js being a basic alert(). What am I missing? The error codes read,
[Error] Failed to load resource: Origin null is not allowed by Access-Control-Allow-Origin. (alert.js, line 0)
and
[Error] XMLHttpRequest cannot load file:///Volumes/SSD2/kaely/kaely/alert.js?_=1471148162284. Origin null is not allowed by Access-Control-Allow-Origin.
I'm confused. Any help would be greatly appreciated. Thanks.
Take a look at the answer in this post Origin null is not allowed by Access-Control-Allow-Origin
Your browser (I'm guessing Chrome?) is not allowing this to occur. You could either try testing this in another browser or setting up a local web server.
This question already has answers here:
XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header
(11 answers)
Closed 6 years ago.
This confuses me a lot. Let's say I have 2 tabs open in my browser, one on http://aaa.com and another on http://bbb.com.
Let's say I make a request
$ajax({
method : 'POST',
url : 'http://aaa.com/SomeAction',
...
});
from the JavaScript console of my browser. The way I understand cross-origin policy is that the server only allows that request to happen if the JS console I typed it into was the one in the tab for http://aaa.com. But how does the server know that? Does my browser send it a header that tells it where the request is coming from?
is that the server only allows that request to happen if the JS
console I typed it into was the one in the tab for http://aaa.com
Not true.
Nothing stops example.com from sending an AJAX request to example.org. The Same Origin Policy however will prevent example.com from reading the response returned.
The Same Origin Policy is enforced in the client-side browser, not on the server.
This question already has answers here:
Origin null is not allowed by Access-Control-Allow-Origin
(8 answers)
Closed 8 years ago.
How to avoid "Request header field Authorization is not allowed by Access-Control-Allow-Headers" error running JavaScript from local drive?
So I cannot modify server headers as there is no server.
Thank you.
That is not duplicate as solution offered at 'Origin null is not allowed by Access-Control-Allow-Origin' does not work, you can read about it there.
No. You will need a server like Mongoose (very simple download and run in your root). A very easy fix.