CODEWITHSUNDEEP
angulartypescriptangular-material
Beforeu
Beforeu

Reputation: 83

Angular custom control - star rating - value from input

<div class="rating">
<div style="display: inline-block"
  *ngFor="let starred of stars; let i = index"
  (click)="rate(i + (starred ? (value > i + 1 ? 1 : 0) : 1))">
      <ng-container *ngIf="starred; else noStar"><mat-icon class="filled">star</mat-icon></ng-container>
      <ng-template #noStar><mat-icon class="empty">star_outline</mat-icon></ng-template>
    </div>
</div>   


 @Component({
  selector: 'jfg-star-rating',
  templateUrl: './star-rating.component.html',
  styleUrls: ['./star-rating.component.scss'],
  providers: [
    {
      provide: NG_VALUE_ACCESSOR,
      useExisting: forwardRef(() => StarRatingComponent),
      multi: true
    }
  ]

})
export class StarRatingComponent implements ControlValueAccessor{

  stars: boolean[] = Array(3).fill(true);

   // Allow the input to be disabled, and when it is make it somewhat transparent.
  @Input() disabled = false;
   @HostBinding('style.opacity')
   get opacity() {
     return this.disabled ? 1 : 1;
   }

   // Function to call when the rating changes.
   onChange = (rating: number) => {
   };

   // Function to call when the input is touched (when a star is clicked).
   onTouched = () => {
   };


   get value(): number {
     if(!this.disabled){
     return this.stars.reduce((total, starred) => {
       return total + (starred ? 1 : 0);
     }, 0);
     }
   }
   rate(rating: number) {
     if (!this.disabled) {
       this.writeValue(rating);
     }
   }

   // Allows Angular to update the model (rating).
   // Update the model and changes needed for the view here.
   writeValue(rating: number): void {
     if (!this.disabled) {
       this.stars = this.stars.map((_, i) => rating > i);
       this.onChange(this.value);
     }

   }

   // Allows Angular to register a function to call when the model (rating) changes.
   // Save the function as a property to call later here.
   registerOnChange(fn: (rating: number) => void): void {
     this.onChange = fn;
   }

   // Allows Angular to register a function to call when the input has been touched.
   // Save the function as a property to call later here.
   registerOnTouched(fn: () => void): void {
     this.onTouched = fn;
   }

   // Allows Angular to disable the input.
   setDisabledState(isDisabled: boolean): void {
     this.disabled = isDisabled;


   }
 }

Im trying to make a component for star rating. I made it to work properly as an input. So i can press on the stars to get the correct value as a formControl and pass it to my services. But my problem is that i have tried to make my component to get value as an @input and set number of stars based on that value. I have tried inputing the value and setting it everywhere i could but still had no effect. If you could suggest me how can i proceed to set value form the input i would be glad :)

Upvotes: 1

Views: 3873

Answers (1)

Sunil
Sunil

Reputation: 11243

You already have implemented ControlValueAccessor so you should be able to set the value by ngModel which is two binding. You don't need any other input to set the value. So you can use your StarRatingComponent as - 

<jfg-star-rating [ngModel]="3"></jfg-star-rating>

OR

<jfg-star-rating [(ngModel)]="rating"></jfg-star-rating>

Working copy is here - https://stackblitz.com/edit/angular-material-sample-vv4s6b

Upvotes: 2

Related Questions