ngrx参数选择功能 [英] ngrx parameter to select function

问题描述

是否可以将参数传递给ngrx select函数?

Is there a way to pass parameters to ngrx select functions?

以下是我的用例:

我正在维护商店中的评论列表.

I am maintaining list of comments in store.

我写了一个组件来代表一个评论.因此，一个CommentComponent知道组件对象的ID

I wrote one component to represent one comment. So, one CommentComponent knows the id of the component object

每个评论将具有likeByBy，reportedBy等属性. 在用户界面中，我正在使用* ngFor

Each comment will have properties like likedBy, reportedBy, ...etc In UI, I am showing all the components using *ngFor

现在，我希望我的CommentComponent通过使用组件的ID仅订阅一个注释对象.

Now I want my CommentComponent to subscribe only to one comment object by using id of the component.

现在，我在顶级组件中订阅所有评论，并将每个评论作为输入传递给CommentCompoent.

Right now I am subscribing to all the comments in a top level component, and passing each comment to the CommentCompoent as an input.

当前的方法并不干净，因为即使只有一个注释发生更改，角度变化检测策略(即使我使用onPush)也必须为所有注释呈现DOM.

Current approach is not clean because angular change detection strategy (even if I use onPush) has to render DOM for all the comments even though only one comment changes.

赞赏任何可以在其中将注释ID传递给选择器功能的建议，以便每个CommentComponent只能订阅一个注释.

Appreciate any suggestions where I can pass comment id to a selector function so that each CommentComponent can subscribe to only one comment.

预先感谢， 苏达喀尔

推荐答案

从NgRx 6.1开始，您可以将选择器与props一起使用.

As of NgRx 6.1, you can use a selector with props.

export const getCount = () =>   
  createSelector(     
    (state, props) => state.counter[props.id],     
    (counter, props) => counter * props.multiply
);

有关更多信息和不同方式，请查看我的文章 NgRx:参数化选择器

For more info and different ways, check out my article NgRx: Parameterized selectors

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