Emberjs filter() 与 filterProperty() [英] Emberjs filter() versus filterProperty()

问题描述

看起来像 filter() 和 filterProperty() 非常相似，都是返回过滤数组的 Enumerable 函数.

在什么情况下我应该使用一种或另一种?

解决方案

更新: filterProperty() 已替换为 filterBy().用法相同，见下方评论.

filterBy() 是 filter() 的快捷方式，可让您根据枚举元素的指定属性快速过滤枚举.如果您需要做一些更复杂或不寻常的事情，而您不能使用 filterBy()，请使用 filter().

例如，假设您有一个这样的对象数组:

<预><代码>[{名字:'克里斯'，姓氏:'塞尔登'}，{firstName: 'Luke', lastName: 'Melia'},{名字:'以前的亚历克斯'，姓氏:'Matchneer'}]

并且您想要一个计算属性，该属性使用过滤器数组来仅包含具有 firstName == 'Luke' 的人:

使用filter():

filterComputed: function() {返回 this.get('content').filter(function(item, index, enumerable){返回 item.firstName == 'Luke';});}.property('content.@each')

使用filterBy():

filterByComputed: function() {返回 this.get('content').filterBy('firstName', 'Luke');}.property('content.@each')

JSBin 示例

It seems like filter() and filterProperty() are quite similar, both are Enumerable functions returning a filtered array.

In what circumstances should I use one or the other?

解决方案

Update: filterProperty() has been replaced by filterBy(). The usage is the same, see comment below.

filterBy() is a shortcut for filter() that lets you quickly filter an enumerable based on a specified property of the elements of the enumerable. Use filter() if you need to do something more complicated or out-of-the-ordinary where you can't use filterBy().

For example, assuming you had an array of objects like this:

[
  {firstName: 'Kris', lastName: 'Selden'},
  {firstName: 'Luke', lastName: 'Melia'},
  {firstName: 'Formerly Alex', lastName: 'Matchneer'}
]

And you wanted to have a computed property that uses filter the array to only include people with the firstName == 'Luke':

using filter():

filterComputed: function() {
  return this.get('content').filter(function(item, index, enumerable){
    return item.firstName == 'Luke';
  });
}.property('content.@each')

using filterBy():

filterByComputed: function() {
  return this.get('content').filterBy('firstName', 'Luke');
}.property('content.@each')

JSBin example

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