AjaxWithGenerators.js

// jQuery AJAX simulator

var $ = {
    ajax: function(opts, returnData, throwError) {
        console.log(`Request URL: ${opts.url}`);
        console.log(`Request data: ${opts.data}`);

        var timer = Math.round() * 10 + 1;

        if (throwError && typeof opts.error === 'function') {
            setTimeout(function() {
                opts.error({
                    message: 'AJAX Request Error!'
                });
            }, timer);

            return;
        }

        if (typeof opts.success === 'function') {
            setTimeout(function() {
                opts.success(returnData);
            }, timer);
        }
    }
};

// Simple wrapper for $.ajax() call

function request(opts, returnData, throwError) {
    opts.success = function(result) {
        it.next(result);
    };

    opts.error = function(err) {
        it.throw(err.message);
    };

    $.ajax(opts, returnData, throwError);
}

// The generator method, which starts the requests

function* main() {
    var res =
        yield request({
            url: 'http://example.com/auth'
        }, {
            id: 24
        });

    var user =
        yield request({
            url: 'http://example.com/profile',
            data: res.id
        }, {
            name: 'Karlen'
        });

    console.log('User info: ' + JSON.stringify(user));
}

// Running the generator and starting the first iteration

var it = main();
it.next();