JSPromise

JS Promises/A+ implementation

Instance API

• promise
• then
• resolve
• fulfill
• reject
• always
• done
• fail
• isFulfilled
• isPending
• isRejected
• isResolved

Static API

• allFulfilled
• allResolved
• create
• resolve
• fulfill
• reject
• when
• invoke

Instance API###

new JSPromise()####

Constructor, creates a new promise object

promise = new JSPromise();

promise.then([onFulfilled], [onRejected])####

See https://github.com/promises-aplus/promises-spec#the-then-method

promise2 = promise1.then(onFulfilled, onRejected);

promise.resolve([value])####

Resolves the promise according to promise resolution procedure

promise.resolve(42);

promise.fulfill([result])####

Fulfills promise with result

promise.fulfill(42);

promise.reject([reason])####

Rejects promise with reason

promise.reject( new Error("Awesome exception") );

promise.always([onResolved])####

Calls reason when the promise will be resolved

promise.always(function (promise) {
    console.log( promise.isFulfilled() );
});

promise.done([onFulfilled], [onRejected])####

Terminates promise chaining, if the last promise was rejected, an exception will be thrown

promise.then(function () {
    throw 42;
}).done();

promise.fail([onRejected])####

Simple shortcut for promise.then(undefined, onRejected);

promise.fail(myFallback);

promise.isFulfilled()####

Returns true if the promise is in fulfilled state

promise.fulfill();
promise.isFulfilled();  //  -> true

promise.isPending()####

Returns true if promise is in pending state

promise = new JSPromise();
promise.isPending();  //  ->  true
promise.resolve()
promise.isPending();  //  -> false

promise.isRejected()####

Returns true if the promise is in rejected state

promise.reject();
promise.isRejected(); //  -> true

promise.isResolved()####

Returns true if the promise is in one of resolved or rejected states

promise = new JSPromise();
 
promise.isResolved(); //  -> false
promise.fulfill();
promise.isResolved(); //  -> true
 
promise = new JSPromise();
promise.reject();
promise.isResolved(); //  -> true

Static API###

JSPromise.allFulfilled(promises)####

Creates a new promise to be fulfilled when all given promises will be fulfilled. Promise will be rejected if any of given promises will be rejected

promise1 = new JSPromise();
promise1.fulfill(6);
promise2 = new JSPromise();
 
JSPromise.allFulfilled([5, promise1, promise2]).then(function (results) {
    console.log(results); // [5, 6, 7];
});
 
setTimeout(function () {
    promise2.fulfill(7);
}, 100);

JSPromise.allResolved(promises)####

Creates a new promise to be resolved when all given promises will bew resolved

promise1 = new JSPromise();
promise1.reject(6);
promise2 = new JSPromise();
 
JSPromise.allResolved([5, promise1, promise2]).then(function (results) {
    console.log(results.map(function (promise) {
        return promise.valueOf();
    })); // [5, 6, 7];
});
 
setTimeout(function () {
    promise2.fulfill(7);
}, 100);

JSPromise.create([result])####

Creates a new promise and resolves it, if given value is thenable

JSPromise.create(5);  // -> {JSPromise}

JSPromise.resolve([value])####

Resolves value and returns a new promise

promise = JSPromise.resolve(42);

JSPromise.fulfill([result])####

Fulfills a new promise with given result

JSPromise.fulfill(42);

JSPromise.reject([reason])####

Creates a new promise and rejects it with given reason

JSPromise.reject(42);

JSPromise.when([result], [onFulfilled], [onRejected])####

Creates a new promise to be resolved when result will be resolved according to promise resolution procedure. onFulfilled and onRejected callbacks can be passed.

JSPromise.when(42, function (result) {
    console.log(result); // -> 42
});

JSPromise.invoke(fn)####

Calls the given function and resolves new promise with returned value

JSPromise.invoke(function (result) {
    return result;
}, null, 42).then(function (res) {
    console.log(res); // -> 42
})