Apply a directive conditionally

Question

I am using Material 2 to add md-raised-button. I want to apply this directive only if certain condition becomes true.

For example:

<         


        

Answer 1

I couldn't find a nice existing solution, so i built my own directive which does this.

import { Directive, ElementRef, Input } from '@angular/core';

@Directive({
  selector: '[dynamic-attr]'
})
export class DynamicAttrDirective {
  @Input('dynamic-attr') attr: string;
  private _el: ElementRef;

  constructor(el: ElementRef) {
    this._el = el;
  }

  ngOnInit() {
    if (this.attr === '') return null;
    const node = document.createAttribute(this.attr);
    this._el.nativeElement.setAttributeNode(node);
  }
}

Then your html: