Be taught Angular 11 MatDialog Fundamentals

Of all of the Angular Materials parts, the MatDialog simply could be the most complicated. On the identical 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 substitute the usual JavaScript affirm dialog that we applied 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’ll 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() technique accepts a part to indicate within the physique of the dialog. You may be tempted to create the part as a baby to the one that may name it, but it surely may be clever to assume twice earlier than doing in order we might prefer to reuse the identical dialog in different places inside out software sooner or later. For that motive, I might advocate producing it throughout the app listing:

ng g c confirm-dialog

Within the confirm-dialog.part.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.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: MatDialogRefConfirmDialogComponent>,
    @Inject(MAT_DIALOG_DATA) public knowledge: any) 
  { }
}

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

  
{{knowledge.dialogMessageLine1}}

  {{knowledge.dialogMessageLine2}}p>

Invoking the MatDialog Service

Again within the survey.part.ts file, we’re able to replace the canExit() technique to current our customized dialog as an alternative 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() technique. It’s liable for exhibiting the dialog.
3. Invoke the openUnsavedChangesDialog() technique 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;
  };

  non-public openUnsavedChangesDialog(): Observable {
    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '26.5rem',
      knowledge: { 
        dialogTitle: 'Unsaved Adjustments', 
        dialogMessageLine1: 'You've gotten unsaved modifications.',
        dialogMessageLine2: 'Are you certain you need 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 loads happening on this little technique, so let’s unpack it.

The dialog reference that we injected by way of the constructor gives quite a few strategies, properties, and occasion hooks for working with it, an important of which being the open() technique. 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 info 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 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 kind to canExit() to accommodate the afterClosed() return worth.

Right here’s the top results of at this time’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 discovered find out how to use the MatDialog, essentially the most complicated, and but most versatile Angular Materials part. To try this, we changed the usual JavaScript affirm dialog that we applied within the Stopping Knowledge Loss In Angular Functions utilizing a CanDeactivate Route Guard demo with a MatDialog.