84 lines
2.3 KiB
JavaScript
84 lines
2.3 KiB
JavaScript
|
// MIT license (by Elan Shanker).
|
||
|
|
(function(globals) {
|
||
|
|
'use strict';
|
||
|
|
|
||
|
|
var executeSync = function(){
|
||
|
|
var args = Array.prototype.slice.call(arguments);
|
||
|
|
if (typeof args[0] === 'function'){
|
||
|
|
args[0].apply(null, args.splice(1));
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
var executeAsync = function(fn){
|
||
|
|
if (typeof setImmediate === 'function') {
|
||
|
|
setImmediate(fn);
|
||
|
|
} else if (typeof process !== 'undefined' && process.nextTick) {
|
||
|
|
process.nextTick(fn);
|
||
|
|
} else {
|
||
|
|
setTimeout(fn, 0);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
var makeIterator = function (tasks) {
|
||
|
|
var makeCallback = function (index) {
|
||
|
|
var fn = function () {
|
||
|
|
if (tasks.length) {
|
||
|
|
tasks[index].apply(null, arguments);
|
||
|
|
}
|
||
|
|
return fn.next();
|
||
|
|
};
|
||
|
|
fn.next = function () {
|
||
|
|
return (index < tasks.length - 1) ? makeCallback(index + 1): null;
|
||
|
|
};
|
||
|
|
return fn;
|
||
|
|
};
|
||
|
|
return makeCallback(0);
|
||
|
|
};
|
||
|
|
|
||
|
|
var _isArray = Array.isArray || function(maybeArray){
|
||
|
|
return Object.prototype.toString.call(maybeArray) === '[object Array]';
|
||
|
|
};
|
||
|
|
|
||
|
|
var waterfall = function (tasks, callback, forceAsync) {
|
||
|
|
var nextTick = forceAsync ? executeAsync : executeSync;
|
||
|
|
callback = callback || function () {};
|
||
|
|
if (!_isArray(tasks)) {
|
||
|
|
var err = new Error('First argument to waterfall must be an array of functions');
|
||
|
|
return callback(err);
|
||
|
|
}
|
||
|
|
if (!tasks.length) {
|
||
|
|
return callback();
|
||
|
|
}
|
||
|
|
var wrapIterator = function (iterator) {
|
||
|
|
return function (err) {
|
||
|
|
if (err) {
|
||
|
|
callback.apply(null, arguments);
|
||
|
|
callback = function () {};
|
||
|
|
} else {
|
||
|
|
var args = Array.prototype.slice.call(arguments, 1);
|
||
|
|
var next = iterator.next();
|
||
|
|
if (next) {
|
||
|
|
args.push(wrapIterator(next));
|
||
|
|
} else {
|
||
|
|
args.push(callback);
|
||
|
|
}
|
||
|
|
nextTick(function () {
|
||
|
|
iterator.apply(null, args);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
};
|
||
|
|
};
|
||
|
|
wrapIterator(makeIterator(tasks))();
|
||
|
|
};
|
||
|
|
|
||
|
|
if (typeof define !== 'undefined' && define.amd) {
|
||
|
|
define([], function () {
|
||
|
|
return waterfall;
|
||
|
|
}); // RequireJS
|
||
|
|
} else if (typeof module !== 'undefined' && module.exports) {
|
||
|
|
module.exports = waterfall; // CommonJS
|
||
|
|
} else {
|
||
|
|
globals.waterfall = waterfall; // <script>
|
||
|
|
}
|
||
|
|
})(this);
|