Study Angular 11 MatDialog Fundamentals

Of all of the Angular Materials elements, the MatDialog simply stands out as the most complicated. 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 change the usual JavaScript verify dialog that we carried out within the Stopping Knowledge Loss In Angular Functions 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 are going to 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 element to indicate within the physique of the dialog. You is perhaps tempted to create the element as a baby to the one that can name it, nevertheless it is perhaps sensible to suppose twice earlier than doing in order we could wish to reuse the identical dialog in different places inside out software sooner or later. For that purpose, I’d 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 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 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.element.html file:

  
{{information.dialogMessageLine1}}

  {{information.dialogMessageLine2}}p>

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

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

    return dialogRef.afterClosed();
  }
}

The openUnsavedChangesDialog() Methodology Defined

There’s rather a lot 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, a very powerful 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 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 by way of the sure [mat-dialog-close] attribute:

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

Right here’s the tip results of right now’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 Dwelling hyperlink:

Conclusion

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