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angularngxs

Class based object instances for state in NGXS

NGXS Style Guide has a point:

It is not recommended to add Class based object instances to your state because this can lead to undefined behavior in the future.

e.g. 

//== This is NOT recommended:
ctx.setState((state: Todo[]) => state.concat(new Todo(action.title)));

//== This is recommended
state.concat({ title: action.title, isCompleted: false })

Why creating class instance with new is not recommended?

Solution

  • Because those created objects have multiple properties, like functions, constructor, maybe private properties and so on ... you dont want to save those properties too!

    You should have an export-function in your Todo-class:

    interface TodoModel {
  /* your properties you want to take care of! */
}

class Todo implements TodoModel {
  export(): TodoModel {
  }

  import(model: TodoModel) {
  }
}