Angular Model Pattern - model mutation

ampe-mutate.ts

@Injectable()
export class TodosService {

  /* ... */
    
  // pass all neccessary data as funcion parameters 
  toggleTodo(name: string) {

    // retrieve model internal state
    const todos = this.model.get();

    // mutate model internal state
    todos.forEach(t => {
      if (t.name === name) {
        t.done = !t.done;
      }
    });

    // set new model state; and notify all subscribed componenets
    this.model.set(todos);
  }

}