Be taught Angular 11 MatDialog Fundamentals

Of all of the Angular Materials elements, the MatDialog simply often is 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 part 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 verify dialog that we carried out within the Stopping Information Loss In Angular Purposes 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 Part

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

ng g c confirm-dialog

Within the confirm-dialog.part.ts file, we are going to modify the constructor to just accept a reference to the dialog in addition to the information that we are going to cross to it:

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

@Part({
  selector: 'app-confirm-dialog',
  templateUrl: './confirm-dialog.part.html',
  styleUrls: ['./confirm-dialog.component.css'],
  // this can permit 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.part.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="major" [mat-dialog-close]="true">{{information.yesButtonText}}</button>
</div>

Invoking the MatDialog Service

Again within the survey.part.ts file, we’re able to replace the canExit() methodology to current our customized dialog as an alternative of the native JavaScript verify 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 answerable for displaying the dialog.
3. Invoke the openUnsavedChangesDialog() methodology from canExit().

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

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

// SatisfactionRatings enum

@Part({
  selector: "app-survey",
  templateUrl: "./survey.part.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 may have unsaved modifications.',
        dialogMessageLine2: 'Are you positive you need to depart the web page?',
        yesButtonText: 'Depart this Web page',
        noButtonText: 'Keep on this Web page'
      }
    });

    return dialogRef.afterClosed();
  }
}

The openUnsavedChangesDialog() Methodology Defined

There’s rather a lot happening on this little methodology, so let’s unpack it.

The dialog reference that we injected by way of the constructor offers quite a few strategies, properties, and occasion hooks for working with it, an important of which being the open() methodology. It accepts the part 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 part.

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 by way of 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="major" [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 tip results of right this moment’s updates to the Stopping Information 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 Dwelling hyperlink:

Conclusion

On this tutorial, we discovered find out how to use the MatDialog, probably the most advanced, and but most versatile Angular Materials part. To try this, we changed the usual JavaScript verify dialog that we carried out within the Stopping Information Loss In Angular Purposes utilizing a CanDeactivate Route Guard demo with a MatDialog.