Mat-autocomplete - 显示名称但保存用户 ID 值

Question

I am trying to implement autocomplete, however I want to save the selected user ID in the database.

That is, in autocomplete I want to appear user name to select, but as a return value I do not want the name, but its ID.

I think my problem is in this line:

this.userService.getUsers().subscribe(
      (val: any[]) =>{
        this.allFruits = val.map(user => user.username);
        this.fruitCtrl.setValue(null); 
      } 
    )

My Code --Stackblitz

Stackblitz

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); 
      } 
    )
  }

  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);
  }

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>

Answer 1

You definitely want to have stream of objects, not strings in this.filteredFruits . With current code base, you would have to find and id of selected string, which sounds fragile - better don't separate key/value pairs from each other or might face bugs when wrong id is used.

this.allFruits = val;

Then change this._filter function to filter object[] not string[] :

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

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

And for Mat Option:

<mat-option *ngFor="let fruit of filteredFruits | async" [value]="fruit.id">    
  {{fruit.name}}
</mat-option>

Now fruitCtrl should have an id as a value