@Select 嵌套对象和状态不变性

Question

我使用 NGXS 有一段时间了，发现如果在@Select return中使用对象或数组，它会破坏组件中状态的不变性。

示例：

state: AppStateModel = {
  justValue: true,
  complexObject: { a:1, b:2}
}

然后是两个选择器：

// Here in a component we will get access to object by link and can modify it in state without patchState or setState
  @Selector()
  static getComplexObject(state: AppStateModel) {
    return state.complexObject;
  }

// That will work fine since JS will return it as a value (simple types) not a link
  @Selector()
  static getJustValue(state: AppStateModel) {
    return state.justValue;
  }

我看到的解决方案如：

  // Here we can apply DeepCopy method to decople object from the state, and keep immutability no matter what happens in the components
  @Selector()
  static getComplexObject(state: AppStateModel) {
    return clone(state.complexObject);
  }

我的问题是这样做正确吗？或者 Ngxs 有一些内置的解决方案。

提前致谢！

Answer 1

例如，您可以 Object.freeze() 在开发模式下 https://medium.com/ngxs/immutable-state-in-ngxs-part-i-ba318bfc5bb3

@Select 嵌套对象和状态不变性

@Select of nested object and immutability of state

immutability

deep-copy

state-management

angular

ngxs