Study Angular 11 MatDialog Fundamentals

Of all of the Angular Materials parts, the MatDialog simply could be the most advanced. On the similar time, it’s most likely additionally probably the most versatile of the bunch. A part of the reason being that it’s not a element a lot as a service that may be utilized to open modal dialogs with Materials Design styling and animations. On this tutorial, we’ll substitute the usual JavaScript affirm dialog that we carried out within the Stopping Knowledge Loss In Angular Functions utilizing a CanDeactivate Route Guard tutorial with a MatDialog:

JavaScript Verify Dialog

Angular Verify Dialog

Including MatDialog to the Materials Module File

Recall that we positioned all of our Angular Materials imports within the srcappsharedmodulesmaterialmaterial.module.ts file. We are going to now add MatDialog to the record:

import {MatDialogModule} from '@angular/materials/dialog';

const materialModules = [
  //...
  MatToolbarModule,
  MatDialogModule
];

Creating the ConfirmDialog Element

A part of what makes MatDialog so versatile is that its open() methodology accepts a element to indicate within the physique of the dialog. You may be tempted to create the element as a toddler to the one that may name it, but it surely may be sensible to suppose twice earlier than doing in order we could prefer to reuse the identical dialog somewhere else inside out software sooner or later. For that motive, I might suggest producing it throughout the app listing:

ng g c confirm-dialog

Within the confirm-dialog.element.ts file, we’ll modify the constructor to simply accept a reference to the dialog in addition to the information that we’ll cross to it:

import { Element, Inject, ViewEncapsulation } from '@angular/core';
import { MatDialogRef, MAT_DIALOG_DATA } from '@angular/materials/dialog';

@Element({
  selector: 'app-confirm-dialog',
  templateUrl: './confirm-dialog.element.html',
  styleUrls: ['./confirm-dialog.component.css'],
  // it will enable us to override the mat-dialog-container CSS class
  encapsulation: ViewEncapsulation.None
})
export class ConfirmDialogComponent {

  constructor(
    public dialogRef: MatDialogRef<ConfirmDialogComponent>,
    @Inject(MAT_DIALOG_DATA) public knowledge: any) 
  { }
}

Subsequent, we’ll add the contents of the dialog to the confirm-dialog.element.html file:

<div class="dialog-header accent-background">
  <span class="dialog-header-title">{{knowledge.dialogTitle}}</span>
</div>
<div class="dialog-content">
  <p>{{knowledge.dialogMessageLine1}}<br/>
  {{knowledge.dialogMessageLine2}}</p>
</div>
<div class="dialog-footer">
  <button class="standard-button dialog-button" mat-raised-button [mat-dialog-close]="false" cdkFocusInitial>{{knowledge.noButtonText}}</button>
    
  <button mat-raised-button coloration="main" [mat-dialog-close]="true">{{knowledge.yesButtonText}}</button>
</div>

Invoking the MatDialog Service

Again within the survey.element.ts file, we’re able to replace the canExit() methodology to current our customized dialog as a substitute of the native JavaScript affirm dialog. There are three issues we have to do to make that occur:

1. Add a constructor that accepts a MatDialog reference.
2. Add the openUnsavedChangesDialog() methodology. It’s liable for exhibiting the dialog.
3. Invoke the openUnsavedChangesDialog() methodology from canExit().

Right here is the up to date supply code for the survey.element.ts file that reveals the related modifications:

// imports
import { MatDialog } from "@angular/materials/dialog";
import { ConfirmDialogComponent } from "../confirm-dialog/confirm-dialog.element";

// SatisfactionRatings enum

@Element({
  selector: "app-survey",
  templateUrl: "./survey.element.html",
  styleUrls: ["./survey.component.css"]
})
export class SurveyComponent implements IDeactivateComponent {
  // declarations

  constructor(public dialog: MatDialog) { }

  //strategies...

  public canExit(): boolean | Observable<boolean> {
    return this.ngFormRef.soiled
      ? this.openUnsavedChangesDialog()
      : true;
  };

  non-public openUnsavedChangesDialog(): Observable<boolean> {
    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '26.5rem',
      knowledge: { 
        dialogTitle: 'Unsaved Modifications', 
        dialogMessageLine1: 'You have got unsaved modifications.',
        dialogMessageLine2: 'Are you certain you wish to depart the web page?',
        yesButtonText: 'Go away this Web page',
        noButtonText: 'Keep on this Web page'
      }
    });

    return dialogRef.afterClosed();
  }
}

The openUnsavedChangesDialog() Technique Defined

There’s lots occurring on this little methodology, so let’s unpack it.

The dialog reference that we injected through the constructor offers quite a few strategies, properties, and occasion hooks for working with it, crucial of which being the open() methodology. It accepts the element to show in addition to a MatDialogConfig object. That’s the place we set the dialog’s look and cross alongside the information object that populates the dialog element.

The afterClosed() occasion hook receives an observable that’s notified when the dialog is completed closing. We are able to do no matter processing we have to do after the dialog is closed. In our case, we don’t have to do something however cross alongside the worth returned by the dialog. That will get set by the 2 buttons within the footer through the sure [mat-dialog-close] attribute:

<div class="dialog-footer">
  <button class="standard-button dialog-button" mat-raised-button [mat-dialog-close]="false" cdkFocusInitial>{{knowledge.noButtonText}}</button>
  &nbsp;&nbsp;
  <button mat-raised-button coloration="main" [mat-dialog-close]="true">{{knowledge.yesButtonText}}</button>
</div>

We then want so as to add the Observable<boolean> return kind to canExit() to accommodate the afterClosed() return worth.

Right here’s the top results of immediately’s updates to the Stopping Knowledge Loss In Angular Functions utilizing a CanDeactivate Route Guard demo. To check it, navigate to the Survey web page, work together with the shape in order to replace the underlying mannequin, after which click on the Residence hyperlink:

Conclusion

On this tutorial, we realized the best way to use the MatDialog, probably the most advanced, and but most versatile Angular Materials element. To try this, we changed the usual JavaScript affirm dialog that we carried out within the Stopping Knowledge Loss In Angular Functions utilizing a CanDeactivate Route Guard demo with a MatDialog.