Is it possible to delay the execution of the onkeypress event by one second in order to prevent it from triggering a method multiple times consecutively?

Question

Is it possible to delay the execution of the onkeypress event by one second in order to prevent it from triggering a method multiple times consecutively?

Currently, I am developing a program that utilizes a method to display data in a table using a textbox. The issue is that the program is being called more than 10 times with each execution. Is there any way to prevent this from happening?

The textbox element is displayed below:

<input #input matInput placeholder="Search data" (keyup)="onKeypressEvent($event)">

Below is the method being invoked:

  onKeypressEvent(event: any){
    fromEvent(this.input.nativeElement,'keyup')
        .pipe(
            debounceTime(150),
            distinctUntilChanged(),
            tap(() => {
                this.paginator.pageIndex = 0;
                this.loadData();
            })
        )
        .subscribe();
  }

angular typescript rxjs angular-material

Answer 1

Answer №1

The reason for this issue is that a new chain is created with every key press, rendering debounceTime() ineffective. To address this, it's recommended to create a Subject and push key presses into it. Then, establish just one subscription either in the constructor or within onInit():

keyPress$ = new Subject();

...

keyPress$.pipe(
  debounceTime(150),
  distinctUntilChanged(),
  tap(() => {
    this.paginator.pageIndex = 0;
    this.loadData();
  }),
).subscribe();

...

onKeypressEvent(event: any) {
  this.keyPress$.next(event);
});

Answer 2

The reason for this issue is that a new chain is created with every key press, rendering debounceTime() ineffective. To address this, it's recommended to create a Subject and push key presses into it. Then, establish just one subscription either in the constructor or within onInit():

keyPress$ = new Subject();

...

keyPress$.pipe(
  debounceTime(150),
  distinctUntilChanged(),
  tap(() => {
    this.paginator.pageIndex = 0;
    this.loadData();
  }),
).subscribe();

...

onKeypressEvent(event: any) {
  this.keyPress$.next(event);
});

Answer 3

Answer №2

Your current code appears to be utilizing @viewChild().

Here is a simple and functional alternative that eliminates the need for an extra Subject.

ngAfterViewInit() {
    fromEvent(this.input.nativeElement, "keyup")
      .pipe(debounceTime(1000)) // Adjust debounceTime as needed
      .subscribe((val: KeyboardEvent) => {
        console.log(this.input.nativeElement.value);
      });
  }

Remember to unsubscribe in the onDestroy method.

Answer 4

Your current code appears to be utilizing @viewChild().

Here is a simple and functional alternative that eliminates the need for an extra Subject.

ngAfterViewInit() {
    fromEvent(this.input.nativeElement, "keyup")
      .pipe(debounceTime(1000)) // Adjust debounceTime as needed
      .subscribe((val: KeyboardEvent) => {
        console.log(this.input.nativeElement.value);
      });
  }

Remember to unsubscribe in the onDestroy method.

Is it possible to delay the execution of the onkeypress event by one second in order to prevent it from triggering a method multiple times consecutively?

Answer №1

Answer №2

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