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How to add mattooltip by custom directive in Angular

I am creating a custom directive called TooltipDirective whihc is going to add matTooltip to every host element, code is like below

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

@Directive({
    selector: '[tooltip]'
})
export class TooltipDirective implements OnInit
{
    @Input() tooltip: string;
    constructor(private hostElement: ElementRef, private renderer: Renderer)
    {

    }

    ngOnInit()
    {
        this.renderer.setElementAttribute(this.hostElement.nativeElement, 'matTooltip', this.tooltip);
    }
}

In my html I have two elements to compare the result

<i class="material-icons" tooltip="Test Tooltip">reply_all</i>
<i class="material-icons" matTooltip="Test Tooltip">reply_all</i>

in the result html tooltip and mattooltip attributes are added but it doesn’t show the tooltip.

and rendered html is like below

<i _ngcontent-c10="" class="material-icons" tooltip="Test Tooltip" mattooltip="Test Tooltip" ng-reflect-tooltip="Test Tooltip">reply_all</i>
<i _ngcontent-c10="" class="material-icons" mattooltip="Test Tooltip" aria-describedby="cdk-describedby-message-1" cdk-describedby-host="" ng-reflect-message="Test Tooltip">reply_all</i>

I tried adding other extra attributes but still doesn’t work.

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Answer

The other answer and comments are correct, btw finally I made it like this and it’s working

import { Directive, ElementRef, Inject, Input, NgZone, Optional, ViewContainerRef } from '@angular/core';
import
{
    MAT_TOOLTIP_DEFAULT_OPTIONS,
    MAT_TOOLTIP_SCROLL_STRATEGY,
    MatTooltip,
    MatTooltipDefaultOptions
} from '@angular/material/tooltip';
import { AriaDescriber, FocusMonitor } from '../../../../../node_modules/@angular/cdk/a11y';
import { Directionality } from '../../../../../node_modules/@angular/cdk/bidi';
import { Overlay, ScrollDispatcher } from '../../../../../node_modules/@angular/cdk/overlay';
import { Platform } from '../../../../../node_modules/@angular/cdk/platform';

@Directive({
    selector: '[tooltip]',
    exportAs: 'tooltip'
})
export class TooltipDirective extends MatTooltip
{
    @Input()
    get tooltip()
    {
        return this.message;
    }
    set tooltip(value: string)
    {
        this.message = value;
    }

    constructor(
        _overlay: Overlay,
        _elementRef: ElementRef,
        _scrollDispatcher: ScrollDispatcher,
        _viewContainerRef: ViewContainerRef,
        _ngZone: NgZone,
        _platform: Platform,
        _ariaDescriber: AriaDescriber,
        _focusMonitor: FocusMonitor,
        @Inject(MAT_TOOLTIP_SCROLL_STRATEGY) _scrollStrategy: any,
        @Optional() _dir: Directionality,
        @Optional() @Inject(MAT_TOOLTIP_DEFAULT_OPTIONS)
        _defaultOptions: MatTooltipDefaultOptions)
    {
        super(
            _overlay,
            _elementRef,
            _scrollDispatcher,
            _viewContainerRef,
            _ngZone,
            _platform,
            _ariaDescriber,
            _focusMonitor,
            _scrollStrategy,
            _dir,
            _defaultOptions
        );
    }
}
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