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ember-computed-reverse.js
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ember-computed-reverse.js
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(function(Ember) {
/**
A computed property which returns a reversed array without
recreating a new array on each replace action.
Example
```javascript
App.Timeline = Ember.Object.extend({
reverseChronPosts: Ember.computed.reverse('posts')
});
var timeline = App.Timeline.create({posts: [
'good morning',
'grabbing lunch',
'making dinner'
]});
timeline.get('reverseChronPosts'); // ['making dinner', 'grabbing lunch', 'good morning']
```
@method computed.reverse
@for Ember
@param {String} dependentKey
@return {Ember.ComputedProperty} computes an array with the elements
from the dependent array reversed
*/
var get = Ember.get,
lengthProp = 'length';
Ember.computed.reverse = function(dependentKey) {
return Ember.arrayComputed(dependentKey, {
addedItem: function(array, item, changeMeta) {
array.insertAt(get(array, lengthProp) - changeMeta.index, item);
return array;
},
removedItem: function(array, item, changeMeta) {
array.removeAt(get(array, lengthProp) - changeMeta.index - 1);
return array;
}
});
};
})(Ember);