How do i detect laravel response header?
My javascript to check is but it doesn't work
if (xhr.getResponseHeader('location'))
{
console.log(xhr.getResponseHeader('location'));
}
and this is my server code to redirect
Redirect::guest('landing');
Try this javascript to get the headers of the current page:
var request = new XMLHttpRequest();
request.open('HEAD', document.location, false);
request.send(null);
console.log(request.getAllResponseHeaders());
Than you can see if there is a laravel header being sent or not
Related
The exact error that I am struggling with is "Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.".
I am trying to fetch JSON data using JavaScript from https://api.kraken.com/0/public/OHLC?pair=ETHEUR. I created a XMLHttpRequest object to do this, and specified GET as the type of request. This is supposedly a simple request, however the error says that a preflight request was sent. What is the reason for this behavior? That being said, to fix this error I tried to set a request header in which I specified '*' as the value for the Access-Control-Allow-Origin, yet I still get an error. I have looked through responses to similar questions as mine, but haven't been able to figure out how to solve the problem I am dealing with. This is probably due to still being very new to JavaScript. Either way, below is the code that I have written:
var requestURL = 'https://api.kraken.com/0/public/OHLC?pair=ETHEUR'
var request = new XMLHttpRequest();
request.open('GET',requestURL,true);
request.responseType = 'json';
request.onload = function(){
var data = request.response;
console.log(data);
}
request.setRequestHeader('Access-Control-Allow-Origin','*');
request.send();
In cases like this where the server you’re trying to make a cross-origin request to doesn’t send the Access-Control-Allow-Origin response header, your only option, if you want to make a request to that server from frontend JavaScript code running in a browser, is to use a CORS proxy. Otherwise, your browser won’t allow your frontend JavaScript code to access the response.
So, you can make your request succeed if you change your code to have something like this:
var proxyURL = 'https://cors-anywhere.herokuapp.com';
var requestURL = 'https://api.kraken.com/0/public/OHLC?pair=ETHEUR';
var request = new XMLHttpRequest();
request.open('GET', proxyURL + '/' + requestURL, true);
That sends the request through https://cors-anywhere.herokuapp.com, which forwards the request to https://api.kraken.com/0/public/OHLC?pair=ETHEUR and then receives the response. The https://cors-anywhere.herokuapp.com backend adds the Access-Control-Allow-Origin header to the response and passes that back to your requesting frontend code.
The browser will then allow your frontend code to access the response because that response with the Access-Control-Allow-Origin response header is what the browser sees.
You can also easily set up your own CORS proxy using https://github.com/Rob--W/cors-anywhere/
Note also that request.setRequestHeader('Access-Control-Allow-Origin','*') needs to be removed from the frontend code you are making the request with (as mentioned in comments above).
That’s because Access-Control-Allow-Origin is strictly a response header for servers to send in responses; sending it from the client side in a request will have no effect other than to trigger your browser to do an unnecessary CORS preflight OPTIONS request that will fail.
For details about what browsers do when you send cross-origin requests from frontend JavaScript code using XHR or the Fetch API or AJAX methods from JavaScript libraries—and details about what response headers must be received in order for browsers to allow frontend code to access the responses—see https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS.
var proxyURL = 'https://cors-anywhere.herokuapp.com';
var requestURL = 'https://api.kraken.com/0/public/OHLC?pair=ETHEUR';
var request = new XMLHttpRequest();
request.open('GET', proxyURL + '/' + requestURL, true);
request.responseType = 'json';
request.onload = function() {
var data = request.response;
document.querySelector('pre').textContent = JSON.stringify(data, null, 2);
}
request.send();
<pre></pre>
Is there any way to get content type and content disposition of a url using java-script?
Thanks
Unfortunately, there isn't an API to give you the HTTP response headers for your initial page request.
Accessing the web page's HTTP Headers in JavaScript
Although you could make a new request and read those:
var req = new XMLHttpRequest();
req.open('GET', document.location, false);
req.send(null);
var headers = req.getAllResponseHeaders().toLowerCase();
alert(headers);
The SDK demo works fine (it doesn't need special CORS stuff since it is on the same domain)
When I try to send the request from localhost:8080 this happens
So I'm trying to request api.soundcloud.com/tracks - first my browser sends an OPTIONS req to api.soundcloud.com asking if it's okay to call cross-origin. api.soundcloud.com does not return the headers my browser is looking for so my browser throws an error and can't make the request.
Am I the only person trying to use the APIs from another domain or is something going wrong here?
EDIT: Doing debugging in wireshark - when making an API call using the SDK in the browser an OPTIONS request isn't even being sent. WTF
here's a working example where request is coming from jsbin.com:
var request = new XMLHttpRequest();
request.onreadystatechange = function () {
if (request.readyState === 4 && request.status === 200) {
console.log(request.responseText);
}
};
request.open('GET', 'http://api.soundcloud.com/tracks?client_id=YOUR_CLIENT_ID');
request.send();
I want to extract a page by javascript (client based language) the problem is the third-part remote url doesnt not allow ajax request when i do this req without the header X-REQUESTED-WITH it gives the expected data with 200 Success in response but when i req it with that header it give 403 Forbidden with no content in respone .
i want to know how to req a page without the header X-REQUESTED-WITH in javascript , ajax , jquery or any client based language .
Please help me .
thanks
The X-REQUESTED-WITH header is not "standard". jQuery for instance will add it manually.
So by doing a default XHR request
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if( xhr.readyState === 4 ) {
console.log('done');
}
};
xhr.open('GET', 'hello=50', true);
xhr.setRequestHeader('FOO', 'BAR');
xhr.send(null);
there will not be this header. In the above simplified example we added a custom FOO request header instead, that is the same thing like jQuery adds the X-REQUESTED-WITH header into its ajax requests.
There is a lot of same questions but i cannot find the answer so i am reposing the same question.I am receiving an json request using java script
var request = null;
if (window.XMLHttpRequest) {
request = new XMLHttpRequest();
} else if (window.ActiveXObject) {
request = new ActiveXObject("Microsoft.XMLHTTP");
} else {
return null;
}
request.open("GET", url, true);
request.send(null);
request.onreadystatechange = function() {
if (request.readyState == 4) {
if (request.status == 200) {
}
} else
alert(request.status);
}
I am receiving an status code zero while i receive the request the javascript runs on apache server and json request will be received from tomcat server everything is local . can any one tell me how to over come it.
Note: i cannot use any framework.
I suspect that you are violating the same origin policy restriction that is built in browsers. This restriction prevents you from sending cross domain AJAX requests. So for example if the page containing the AJAX call is hosted on http://localhost/example.htm and you are trying to send an AJAX request to http://localhost:8080/somescript you won't be able to do so because the domains do not match (different ports).
The best way to ensure that your AJAX requests work is by only using relative urls:
request.open("GET", "/somescript", true);