从将按顺序执行的Promise数组中创建一个jQuery Promise

Question

Does jquery have support for forming promises from an array of promises (or functions) to be executed in sequence? For example,

lets suppose I have this function defined

function wait(/*args*/){
    var complete = $.Deferred();
    var args = arguments;
    setTimeout(function(){
        console.log(args);
        //arguments are applied to show that the functionality should
        //pass arguments between promises in sequence.
        complete.resolve.apply(null,args);
    }, 1000);
    return complete.promise();
}

I could easily chain these together to form a new promise like so:

var sequencePromise = wait("first")
.then(wait.bind(null,"second"))
.then(wait.bind(null,"third"));

However i regularly have a long series of promises to sequence, or perhaps they are variable lists i am composing, so I am looking for a way to easily do something like:

var sequence = [
    wait("first"),
    wait.bind(null,"second"),
    wait.bind(null,"third")];

var sequencePromise = $.whenInSeq(sequence)

preferably, I'm looking for a solution that isn't a large dependency (it'd be ideal if I just missed something within the jquery api). Wanted to confirm something doesn't exist before I roll my own.

Answer 1

try this (untested):

var sequence = [
    wait("first"),
    wait.bind(null,"second"),
    wait.bind(null,"third")];

var s = sequence[0];
for (var i = 1; i < sequence.length; i++) {
  s = s.then(sequence[i]);
}
s.done(function () {alert('done!')})