Check link - cross-site Access-Control

Add-ons Development
#1

Hello,

(I’ve been trying to solve this unsuccessfully for days)

How to check a link that is out of origen.

This not work. I need check is link is OK

any idea?

#2

You most likely want a host permission for the resource you’re trying to load: https://developer.mozilla.org/en-US/Add-ons/WebExtensions/manifest.json/permissions#Host_permissions

#3 
      Cross-Origin Request Blocked: The Same

Origin Policy disallows reading the remote resource at
. (Reason: CORS header
‘Access-Control-Allow-Origin’ missing). (unknown)
Hello:

A set

  "permissions": [

    "*://developer.mozilla.org/*",

    "contextMenus",

    "notifications",

    "storage"

  ],

I also tried these

        "webNavigation",

        "webRequest",

        "webRequestBlocking"

    But same warning:

Is there any way to check a link from a website that points to a

website in another domain?

I try to do an extension to check links to web pages.

        I try

to do an extension to check links to web pages (including those
that point to other domains.)

          If I can not verify this, the extension will not

work much.

    For example

function urlExists(url)

    {

        var http = new XMLHttpRequest();

        http.open('HEAD', url);

        http.onreadystatechange = function() {

            if (http.readyState == this.DONE) {

                http.status != 404;

                //document.write("<br>status2: " +

http.status);

                console.log("<br>status1: " + http.status);

            }else{

              console.log("<br>status 404: " + http.status);

            }

        };

        http.send();

    }

                                    I need to be able to

check for example:

    urlExists();

            urlExists();

…