Study Angular 11 MatDialog Fundamentals

Of all of the Angular Materials parts, the MatDialog simply often is the most complicated. On the similar time, it’s most likely additionally essentially 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 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’ll now add MatDialog to the checklist:

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 part to point out within the physique of the dialog. You may be tempted to create the part as a baby to the one that may name it, however it may be clever to suppose twice earlier than doing in order we might wish to reuse the identical dialog somewhere else inside out utility sooner or later. For that cause, I’d advocate producing it throughout the app listing:

ng g c confirm-dialog

Within the confirm-dialog.part.ts file, we are going to modify the constructor to simply accept a reference to the dialog in addition to the information that we’ll move 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.part.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.part.html file:

  
{{information.dialogMessageLine1}}

  {{information.dialogMessageLine2}}p>

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 accountable 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 exhibits the related modifications:

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

// SatisfactionRatings enum

@Element({
  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 {
    return this.ngFormRef.soiled
      ? this.openUnsavedChangesDialog()
      : true;
  };

  personal openUnsavedChangesDialog(): Observable {
    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '26.5rem',
      information: { 
        dialogTitle: 'Unsaved Adjustments', 
        dialogMessageLine1: 'You have got unsaved modifications.',
        dialogMessageLine2: 'Are you certain you wish to go away the web page?',
        yesButtonText: 'Depart this Web page',
        noButtonText: 'Keep on this Web page'
      }
    });

    return dialogRef.afterClosed();
  }
}

The openUnsavedChangesDialog() Methodology Defined

There’s quite a bit occurring on this little methodology, so let’s unpack it.

The dialog reference that we injected by way of the constructor supplies quite a few strategies, properties, and occasion hooks for working with it, crucial 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 move 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 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 move 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:

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

Right here’s the top results of right now’s updates to the Stopping Information 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 House hyperlink:

Conclusion

On this tutorial, we realized tips on how to use the MatDialog, essentially the most complicated, and but most versatile Angular Materials part. To do this, we changed the usual JavaScript verify dialog that we carried out within the Stopping Information Loss In Angular Functions utilizing a CanDeactivate Route Guard demo with a MatDialog.