如何观察数组更改并查看添加了哪个新元素？

Question

onArrayChanged: function(obj, keyName, value) {

    // What is value here, exactly?

}.property('array.@each')

将元素添加到数组时,如何知道添加了哪个值？顺便说一下,当从数组中删除一个值时,我该如何访问它？

Answer 1

看看addArrayObserver,请参阅http://jsfiddle.net/pangratz666/EE65Z/:

var a = Ember.A('a b c d e f g'.w());

var o = Ember.Object.create({
    arrayWillChange: Ember.K,
    arrayDidChange: function(array, start, removeCount, addCount) {
        console.log(arguments);
    }
});

a.addArrayObserver(o);