ViewChild with the focus method

Question

ViewChild with the focus method

This particular component I'm working on has a hidden textarea by default :

<div class="action ui-g-2" (click)="toggleEditable()">edit</div>
<textarea [hidden]="!whyModel.inEdition" #myname id="textBox_{{whyModel.id}}" pInputTextarea focus="true" [(ngModel)]="whyModel.description"></textarea>

My goal is to make the textarea visible and automatically put focus on it when the user clicks on the "edit" div :

@ViewChild('myname') input: ElementRef;
...
private toggleEditable(): void {
  this.whyModel.toggleEditable();
  this.input.nativeElement.focus();
}

The visibility part seems to be functioning correctly, but the autofocus feature is not working as intended. Can anyone provide insight on what might be missing in my implementation?

angular typescript angular2-template

Answer 1

Answer №1

Bindings are typically updated once change detection is triggered, which usually occurs after an event handler has finished executing. However, in your situation, this timing may be too late as the event handler relies on the effects of change detection.

If you need to force immediate (synchronous) change detection, you can do so by calling detectChanges()

constructor(private cdRef:ChangeDetectorRef) {}

@ViewChild('myname') input: ElementRef;
...
private toggleEditable(): void {
  this.whyModel.toggleEditable();
  this.cdRef.detectChanges();
  this.input.nativeElement.focus();
}

Answer 2

Bindings are typically updated once change detection is triggered, which usually occurs after an event handler has finished executing. However, in your situation, this timing may be too late as the event handler relies on the effects of change detection.

If you need to force immediate (synchronous) change detection, you can do so by calling detectChanges()

constructor(private cdRef:ChangeDetectorRef) {}

@ViewChild('myname') input: ElementRef;
...
private toggleEditable(): void {
  this.whyModel.toggleEditable();
  this.cdRef.detectChanges();
  this.input.nativeElement.focus();
}

Answer 3

Answer №2

One way to "force" the focus is by using AfterViewCheck in Typescript. Here's a simplified version of your code for demonstration:

Typescript:

editable;

@ViewChild('myname') input: ElementRef;
private toggleEditable(): void {
    this.editable = !this.editable;
}

ngAfterViewChecked(){
 if(this.editable){
      this.input.nativeElement.focus();
 }
}

HTML

<div class="action ui-g-2" (click)="toggleEditable()">edit</div>
<br>
<textarea [hidden]="!editable" #myname id="textBox_{{id}}" pInputTextarea
   focus="true" [(ngModel)]="description"></textarea>

Example on Stackblitz

Answer 4

One way to "force" the focus is by using AfterViewCheck in Typescript. Here's a simplified version of your code for demonstration:

Typescript:

editable;

@ViewChild('myname') input: ElementRef;
private toggleEditable(): void {
    this.editable = !this.editable;
}

ngAfterViewChecked(){
 if(this.editable){
      this.input.nativeElement.focus();
 }
}

HTML

<div class="action ui-g-2" (click)="toggleEditable()">edit</div>
<br>
<textarea [hidden]="!editable" #myname id="textBox_{{id}}" pInputTextarea
   focus="true" [(ngModel)]="description"></textarea>

Example on Stackblitz

Answer 5

Answer №3

To bring focus to a specific element, you can utilize the @ViewChild method along with focus(). Here is an example of how it can be implemented:

Within the HTML file (abc.component.html)

<form #data="ngForm">
<input class="text-field" type="text" name="name" >
<input class="text-field" type="text" name="surname">
<input class="text-field" type="text" name="company">
</form>


<button type="submit" value="Submit" (click)="submitData(data.value)">Submit</button>


<input class="text-field" type="text" name="City" #setFocusField>
<input class="text-field" type="text" name="State">

In the TypeScript file (abc.component.ts)

@ViewChild('setFocusField') setFocusField: any;

submitData(data:any){
  this.setFocusField.focus();
}

Upon clicking the submit button, the focus will shift to the "City" field.

An alternative approach to achieve the same:

In the code above, instead of using any, we can employ ElementRef in the @ViewChild declaration.

In that scenario, the changes in the TypeScript file would look like this:

(abc.component.ts)

@ViewChild('setFocusField') setFocusField: ElementRef;

submitData(data:any){
  this.setFocusField.nativeElement.focus();
}

Answer 6

To bring focus to a specific element, you can utilize the @ViewChild method along with focus(). Here is an example of how it can be implemented:

Within the HTML file (abc.component.html)

<form #data="ngForm">
<input class="text-field" type="text" name="name" >
<input class="text-field" type="text" name="surname">
<input class="text-field" type="text" name="company">
</form>


<button type="submit" value="Submit" (click)="submitData(data.value)">Submit</button>


<input class="text-field" type="text" name="City" #setFocusField>
<input class="text-field" type="text" name="State">

In the TypeScript file (abc.component.ts)

@ViewChild('setFocusField') setFocusField: any;

submitData(data:any){
  this.setFocusField.focus();
}

Upon clicking the submit button, the focus will shift to the "City" field.

An alternative approach to achieve the same:

In the code above, instead of using any, we can employ ElementRef in the @ViewChild declaration.

In that scenario, the changes in the TypeScript file would look like this:

(abc.component.ts)

@ViewChild('setFocusField') setFocusField: ElementRef;

submitData(data:any){
  this.setFocusField.nativeElement.focus();
}

ViewChild with the focus method

Answer №1

Answer №2

Answer №3

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