Be taught Angular 11 MatDialog Fundamentals

Developer.com content material and product suggestions are editorially impartial. We might earn cash while you click on on hyperlinks to our companions. Be taught Extra.

Of all of the Angular Materials parts, the MatDialog simply could be the most complicated. On the similar time, it’s in all probability 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 change the usual JavaScript affirm dialog that we applied within the Stopping Knowledge Loss In Angular Purposes utilizing a CanDeactivate Route Guard tutorial with a MatDialog:

JavaScript Affirm Dialog

Angular Affirm 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’ll now add MatDialog to the listing:

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 is perhaps tempted to create the element as a toddler to the one that may name it, nevertheless it is perhaps clever to suppose twice earlier than doing in order we might prefer to reuse the identical dialog elsewhere inside out software sooner or later. For that motive, I might advocate producing it inside the app listing:

ng g c confirm-dialog

Within the confirm-dialog.element.ts file, we’ll modify the constructor to just accept a reference to the dialog in addition to the info 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'],
  // this can 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 information: 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">{{information.dialogTitle}}</span>
</div>
<div class="dialog-content">
  <p>{{information.dialogMessageLine1}}<br/>
  {{information.dialogMessageLine2}}</p>
</div>
<div class="dialog-footer">
  <button class="standard-button dialog-button" mat-raised-button [mat-dialog-close]="false" cdkFocusInitial>{{information.noButtonText}}</button>
    
  <button mat-raised-button shade="main" [mat-dialog-close]="true">{{information.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 accountable for displaying 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 exhibits 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',
      information: { 
        dialogTitle: 'Unsaved Modifications', 
        dialogMessageLine1: 'You've gotten unsaved modifications.',
        dialogMessageLine2: 'Are you certain you need to go away the web page?',
        yesButtonText: 'Go away this Web page',
        noButtonText: 'Keep on this Web page'
      }
    });

    return dialogRef.afterClosed();
  }
}

The openUnsavedChangesDialog() Methodology Defined

There’s so much happening on this little methodology, so let’s unpack it.

The dialog reference that we injected through the constructor supplies quite a few strategies, properties, and occasion hooks for working with it, an important 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 info object that populates the dialog element.

The afterClosed() occasion hook receives an observable that’s notified when the dialog is completed closing. We will 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>{{information.noButtonText}}</button>
  &nbsp;&nbsp;
  <button mat-raised-button shade="main" [mat-dialog-close]="true">{{information.yesButtonText}}</button>
</div>

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

Right here’s the top results of as we speak’s updates to the Stopping Knowledge Loss In Angular Purposes 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 House hyperlink:

Conclusion

On this tutorial, we discovered find out how to use the MatDialog, probably the most complicated, and but most versatile Angular Materials element. To do this, we changed the usual JavaScript affirm dialog that we applied within the Stopping Knowledge Loss In Angular Purposes utilizing a CanDeactivate Route Guard demo with a MatDialog.