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How to get previous state from NGXS store

In NGXS we have getState() to get the current state. Is there a way to get the previous state from the store? I am looking for a solution to this as I have to implement Undo/Redo kind of functionality. Thanks!

Solution

  • You can use the store.snapshot() method to get the snapshot of the store at that particular time. You can store the snapshot in a variable and then, in case of a re-roll, just use store.reset() with the snapshot.

    export class MyComponent {

  private initialSnapshot: MyStoreStateModel;

  constructor(private store: Store){
    this.initialSnapshot = store.snapshot();
  }

  // ... component logic / state modification logic

  rollback = () => this.store.reset(this.initialSnapshot); 
}

    Adjust to your needs...

    Hope this helps a little :-)