How to trick a jqXHR to resolve using local data?

Question

This is similar to this question Make jquery jqxhr act like already sending request but that doesn't seem to solve my problem.

I'm using a framework where there are lots of requests done using jQuery ajax methods, and I have to hook in the middle of that (but without touching the original code) to emulate some responses from the server.

With ajaxSend I can detect whenever a request is being send, so at that point I know which ones I want to stop and provide my precomputed response, but I can't find a way to do it. One possible deep level alternative would be to ignore jQuery and go for a Service Worker, but that would restrict the browsers where this will work and it can mean also added complexity to the logic about the precomputed responses, so I would like to stay with a jQuery solution.

For starters I would be happy to have a first step just by being able to stop the request from touching the network, but although I tried to stop the event, the xhr is always executed.

    $( document ).ajaxSend(function(event, request, settings) {
        console.log(request)
        event.preventDefault()
        event.stopPropagation()
        return false;
    }

Then the next step (or may it's this one) is using the request object to resolve the promise, but it doesn't have a 'resolve' method, so I guess that it's a restricted Promise

Can anyone help me to find a solution?

I guess you'll need to decorate (overwrite) `$.ajax` itself. — Bergi, May 05 '16 at 22:44

score 0 · Answer 1 · answered May 05 '16 at 21:56

I did something similar to this a while back by overriding $.ajax.

(function ($) {
    var jqAjax = $.ajax;
    $.ajax = function (settings) {
        if(someCriteriaToDetermineIfItsLocalOrNot) {
           // get from local storage, and return a promise or something
        } else
            return jqAjax(settings);
    };
} (jQuery));

How to trick a jqXHR to resolve using local data?

1 Answers1