EmberArrayAsync.js

EmberArrayAsync.js

/**
 * @main  EmberArrayAsync
 */

/**
* forEachAsync iterates over a large array gradually. The function
* will process items in the array for a given number of ms, stop iterating for
* a given wait time, then proceed and wait until the iteration is complete.
*
* @method forEachAsync
*/

var ASYNC_RUN_TIME = 200;
var ASYNC_WAIT_TIME = 200;

var forEachAsync = function(context, objects, eachFn, completeFn, runTime, wait) {
	if (runTime === null) {
		runTime = ASYNC_RUN_TIME;
	}

	if (wait === null) {
		wait = ASYNC_WAIT_TIME;
	}

	if (!(Ember.Enumerable.detect(objects) || Ember.isArray(objects))) {
		throw new TypeError("Must pass Ember.Enumerable to FilterWait");
	}

	var getTime = function() {
		if (Date.now) {
			return Date.now();
		} else {
			return new Date();
		}
	};

	var processItems = function(items, process, callback) {
		var itemsToProcess = Array.prototype.slice.call(items);
		var i = null;
		var loopFn = function() {
			var start = getTime();
			process.call(context, itemsToProcess.shift(), (i !== null ? ++i : 0));
			while (itemsToProcess.length > 0 && getTime() - start < runTime) {
				process.call(context, itemsToProcess.shift(), ++i);
			}

			if (itemsToProcess.length > 0) {
				return Ember.run.later(context, loopFn, wait);
			} else {
				if ((callback !== null) && (callback.call !== null)) {
					return callback.call(context);
				}
			}
		};
		return Ember.run(context, loopFn);
	};
	return processItems(objects, eachFn, completeFn);
};


/**
* filterAsync iterates over a large array gradually. The function
* will process items in the array for a given number of ms, stop iterating for
* a given wait time, then proceed and wait until the iteration is complete.
*
* @method filterAsync
*/
var filterAsync = function(context, objects, eachFn, completeFn, runTime, wait) {
	var ret = [];
	var filterFn = function(item, i) {
		if (eachFn.call(context, item, i)) {
			ret.push(item);
		}
	};
	var filterComplete = function() {
		completeFn.call(context, ret);
	};
	return forEachAsync(context, objects, filterFn, filterComplete, runTime, wait);
};