Can one use the Fetch API as a Request Interceptor?

Question

I\'m trying to run some simple JS functions after every request to the server with the Fetch API. I\'ve searched for an answer to this question, but haven\'t found any, perh

Answer 1

Since fetch returns a promise, you can insert yourself in the promise chain by overriding fetch:

(function () {
    var originalFetch = fetch;
    fetch = function() {
        return originalFetch.apply(this, arguments).then(function(data) {
            someFunctionToDoSomething();
            return data;
        });
    };
})();

Example on jsFiddle (since Stack Snippets don't have the handy ajax feature)