Promises/A+ library “Ten.Promise” 0.1.0 Released

We released the first version of Ten.Promise on 6 February 2013.

What is Ten.Promise?

Ten.Promise is a JavaScript Promises/A+ library written in TypeScript. Using this library, you can make asynchronous (or async) patterns easier. See following page to know about Promises/A+.

• Promises/A+

As the Promises/A+ specification defines an interface of a promise object and how a promise object treats other promise object, Ten.Promise will work along with other Promises/A+ implementations well.

Downloads

See: Ten.Promise — Promises/A+ library

Where Ten.Promise works

We made sure that Ten.Promise work on following JavaScript processing environment:

• Mozilla Firefox 19,
• Internet Explorer 6, 8, 10,
• Opera 12.13,
• Chrome 24,
• Node 0.8.

We couldn't check on other environments.

Our aim

We aim to let Ten.Promise be a Promises/A+ library having interface-level compatibility with following libraries:

• WinJS.Promise, and
• JSDeferred (except static methods).

Current status

Ten.Promise 0.1.0 passes all of the Promises/A+ tests (version 1.2.0).

And a part of a WinJS.Promise interface is implemented. Implemented constructor and methods are just shown below.

• WinJS.Promise constructor (Ten.Promise constructor)
• WinJS.Promise#then method (Ten.Promise#then method)
• WinJS.Promise#cancel method (Ten.Promise#cancel method)

Big difference between WinJS.Promise and Ten.Promise

These two libraries have difference in the timing of the call of callback functions which are registered with a promise object already fulfilled (or rejected) by its then method:

• A promise object already fulfilled (or rejected) of WinJS.Promise calls a callback function just registered by then method before returning from the method;
• A promise object already fulfilled (or rejected) of Ten.Promise return from then method before a callback function is called.

Ten.Promise is compliant to the Promises/A+ specification, while WinJS.Promise is not.

Example

<script src="Ten.Promise.js"></script>
<script>
// create promise object
var p = new Ten.Promise(function (s,e,p) {
    var count = 0;
    var timerId;
    function timer() {
        setTimeout(function () {
            count++;
            if (count < 5) {
                p(count);
                timer();
            } else {
                s(count);
            }
        }, 4000);
    }
    timer();
});
// register callback functions
p.then(
    function onSuccess(val) { // it is called one time (value: 5)
        console.log("success callback: " + val);
    },
    function onError(err) {}, // in this example, this will not be called
    function onProgress(val) { // it is called four times (respective values: 1, 2, 3, 4)
        console.log("progress callback: " + val);
    });
</script>