Angular 2-使用@ContentChildren过滤组件的内容

我正在尝试实现一个搜索组件，该组件能够在特定子项上触发 search(term:string)函数.如果对子级的搜索失败，则此搜索功能将返回null；如果对子级的搜索成功，则该搜索功能将返回对该子项的引用.

I'm trying to implement a search component being able to trigger a search(term: string) function on specific children. This search function will return null if the search on the child failed or a reference to the child if succeeded.

之所以这样，是因为我想收集"对列表中成功的角度分量的所有引用，以便可以将它们设置为新的" ContentChildren，因此实际上要进行基本过滤..

This is so because I want to "collect" all references to the angular components that succeeded in a list, so that I could set them somehow as 'new' ContentChildren, so actually do basic filtering..

这是我到目前为止所拥有的:

This is what I have so far:

search.component.html

<input (value)="searchterm" />
<ng-content>
    <!-- all components that implements iSearchable here -->
</ng-content>

search.component.ts

...
export class searchComponent implements OnChanges
{
    @Output('searchterm')
    public searchterm: string;

    // 1. Problem: ContentChildren does not work with interfaces?
    @ContentChildren(Isearchable)
    searchContent: QueryList<Isearchable>

    // 2. Problem: ngOnChanges will not fire when searchterm is changed
    ngOnChanges(event)
    {
        var toBeShown = [];

        // go through and let the components filter themselves
        for(let i = 0; i < this.searchContent.length; i++)
        {
            var element: Isearchable = this.searchContent[i];
            var result = element.search();

            if(result != null)  // search suceeded
                toBeShown.push(element);                
        }

        // 3. Problem: how to get them displayed ?
    }
}

基本上我有3个问题:

1.第一个是@ContentChildren()将不接受(是，已导入)Isearchable接口，因为"[ts]找不到名称Isearchable".另外，所有Isearchable组件也都有一个通用的基类，但这也不起作用.

1. The first is that @ContentChildren() won't accept the (yes, imported) interface Isearchable, since '[ts] Cannot find name Isearchable'. Alternatively all Isearchable components also have a common baseclass, but this also do not work.

当前执行程序会给我以下错误:未捕获(承诺):在组件'SearchComponent'的视图上出现意外的指令值'undefined'"

Currently executing the program gives me the following error: "Uncaught (in promise): Unexpected directive value 'undefined' on the View of component 'SearchComponent'"

2.第二个问题是，即使我在输入中键入内容，也不会以某种方式触发ngOnChanges.这必须很简单，我会错过吗?

2. The second problem is that somehow the ngOnChanges won't be fired even if I type into the input. This must be simple, do I miss something?

3.最后，第三个问题是我不完全知道如何使搜索结果(可以是不同的组件类型)显示在DOM中.我的希望实际上是我可以以某种方式双向绑定到@ContentChildren searchcontent.这可能会解决问题，不是吗?

3. Finally, the third problem is that I do not know exactly how to make the search results (that can be of different component types) being displayed in the DOM. My hope is actually that I can somehow two-way bind to the @ContentChildren searchcontent. This would probably solve the problem, wouldn't it?

我真的不知道如何继续，我们将不胜感激！谢谢大家！

I really don't have a clue, how to continue, any help is appreciated! Thank you all!

欢呼