如何刷新 Angular 上的 Font Awesome 图标？

Question

Is there any way to change font awesome icon dynamically? I want user to be able to select one of font awesome icons dynamically. It works only when you add class first time. The place where I try to do it is - MatDialog . There is form where user have to select icon, background color and category name. To select icon user should open another dialog.

I'm using Angular 9.1.4 and Font Awesome 5.13.0 .

---

That's what I tried:

1. Using ngClass

category-dialog.component.html

<div [ngStyle]="selectedColor">
    <i [ngClass]="selectedIcon"></i>
</div>

category-dialog.component.ts

openIconDialog(): void {
  const dialogRef = this.dialog.open(DialogIconSelectComponent, { width: '15rem' });
  dialogRef.afterClosed().subscribe(result => {
    this.selectedIcon = result;
  });
}

This works only first time. But when you try to change icon selectedIcon changes, but UI doesn't refresh element class.

---

2. Using @ViewChild

@ViewChild('iconElement') iconElement: ElementRef;

constructor(private dialog: MatDialog,
            private renderer: Renderer2) { }

openIconDialog(): void {
  const dialogRef = this.dialog.open(DialogIconSelectComponent, { width: '15rem' });
  dialogRef.afterClosed().subscribe((result: string) => {
    this.iconElement.nativeElement.className = result;
  });
}

This also works only first time.

---

3. Using @ViewChild and Renderer2

category-dialog.component.html

<div #colorElement [ngStyle]="selectedColor">
    <i #iconElement></i>
</div>

category-dialog.component.ts

@ViewChild('colorElement') parentElement: ElementRef;
@ViewChild('iconElement') childElement: ElementRef;

constructor(private dialog: MatDialog,
            private renderer: Renderer2) { }

openIconDialog(): void {
  const dialogRef = this.dialog.open(DialogIconSelectComponent, { width: '15rem' });
  dialogRef.afterClosed().subscribe(result => {
    this.replaceIcon(result);
  });
}

replaceIcon(iconClass: string): void {
  const i = this.renderer.createElement('i');
  this.renderer.setProperty(i, 'class', iconClass);
  this.renderer.removeChild(this.parentElement.nativeElement, this.childElement);
  this.renderer.appendChild(this.parentElement.nativeElement, i);
}

That doesn't work at all.

---

Is there any way how to change font awesome dynamically?

Answer 1

Resolution

Wasted lot of my free time to investigate how to resolve this issue. Tried everything with Renderer2 and all dirty Javascript methods. But one day I came up with idea to use innerHtml .

Rendering new string of inner HTML changes Font Awesome icons interactively.

category-dialog.component.html

<div [ngStyle]="selectedColor" [innerHtml]="selectedIconHtml"></div>

category-dialog.component.ts

openIconDialog(): void {
  const dialogRef = this.dialog.open(DialogIconSelectComponent, { width: '15rem' });
  dialogRef.afterClosed().subscribe((result: string) => {
    // EVERY TIME NEW ELEMENT WITH NEW FA CLASS
    this.selectedIconHtml = `<i class="${result}"></i>`;
  });
}

This solution - on every icon selection's changing <div> element content (inner html).

Answer 2

I solved this issue like this:

<div innerHTML="<i class='{{icon}}'></i>">
</div>

In this case, icon will be rerendered after value changes. innerHTML makes this happen easily. No need any code in TS file.