mat-autocomplete 显示名称但获取 ID 值

Question

I am using an autocomplete (Mat-autocomplete) and at the moment it allows loading a list of "users".

In autocomplete, I want to display the username, but I want to save the value of that chosen user ID.

I had this:

 this.allFruits = val.map(user => user.username);

I changed this to get all fields, however I am not able to get the values ​​of the user IDs chosen, can anyone help me?

 this.allFruits = val;

My code DEMO

HTML

<mat-form-field class="example-chip-list">
  <mat-chip-list #chipList>
    <mat-chip
      *ngFor="let fruit of fruits"
      [selectable]="selectable"
      [removable]="removable"
      (removed)="remove(fruit)">
      {{fruit}}
      <mat-icon matChipRemove *ngIf="removable">cancel</mat-icon>
    </mat-chip>
    <input
      placeholder="New fruit..."
      #fruitInput
      [formControl]="fruitCtrl"
      [matAutocomplete]="auto"
      [matChipInputFor]="chipList"
      [matChipInputSeparatorKeyCodes]="separatorKeysCodes"
      [matChipInputAddOnBlur]="addOnBlur"
      (matChipInputTokenEnd)="add($event)">
  </mat-chip-list>
  <mat-autocomplete #auto="matAutocomplete" (optionSelected)="selected($event)">
    <mat-option *ngFor="let fruit of filteredFruits | async" [value]="fruit">
      {{fruit}}
    </mat-option>
  </mat-autocomplete>
</mat-form-field>

component

 constructor(private userService: UserService) {
    this.filteredFruits = this.fruitCtrl.valueChanges.pipe(
        startWith(null),
        map((fruit: string | null) => fruit ? this._filter(fruit) : this.allFruits.slice()));
  }

  ngOnInit() {
    this.userService.getUsers().subscribe(
      (val: any[]) =>{
        this.allFruits = val.map(user => user.username);
        this.fruitCtrl.setValue(null); //use this to apply changes instantly
      } 
    )
  }

  remove(fruit: string): void {
    const index = this.fruits.indexOf(fruit);

    if (index >= 0) {
      this.fruits.splice(index, 1);
    }
  }

  selected(event: MatAutocompleteSelectedEvent): void {
    this.fruits.push(event.option.viewValue);
    this.fruitInput.nativeElement.value = '';
    this.fruitCtrl.setValue(null);
  }

  private _filter(value: string): string[] {
    const filterValue = value.toLowerCase();

    return this.allFruits.filter(fruit => fruit.toLowerCase().indexOf(filterValue) === 0);
  }

Answer 1

Perhaps using a Hashmap might be a good idea in the above scenario

Make a new Map in your class variables as below

allFruits: string[] = [];
nameIdMap =  new Map<string, number>();

Now while initializing allFruits, initialize the map along with it...

 this.allFruits = val.map(user => {
      this.nameIdMap.set(user.username, user.id);
      return user.username
    });

You can obtain this value easily in selected function as stated below, using map.get

selected(event: MatAutocompleteSelectedEvent): void {
  console.log(this.nameIdMap.get(event.option.viewValue));
  this.fruits.push(event.option.viewValue);
  this.fruitInput.nativeElement.value = '';
  this.fruitCtrl.setValue(null);
}

You dont need to write much extra code, neither change any pre-running code. So I think this will work just fine.