Be taught Angular 11 MatDialog Fundamentals

Of all of the Angular Materials elements, 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 substitute the usual JavaScript affirm dialog that we carried out 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 are going to 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() technique accepts a element to indicate within the physique of the dialog. You may be tempted to create the element as a baby to the one that can name it, however it may be sensible to suppose twice earlier than doing in order we might prefer to reuse the identical dialog somewhere else inside out software sooner or later. For that cause, I might advocate producing it inside the app listing:

ng g c confirm-dialog

Within the confirm-dialog.element.ts file, we are going to modify the constructor to simply accept a reference to the dialog in addition to the information that we are going to 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 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 knowledge: any) 
  { }
}

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

  
{{knowledge.dialogMessageLine1}}

  {{knowledge.dialogMessageLine2}}p>

Invoking the MatDialog Service

Again within the survey.element.ts file, we’re able to replace the canExit() technique 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() technique. It’s chargeable for displaying the dialog.
3. Invoke the openUnsavedChangesDialog() technique from canExit().

Right here is the up to date supply code for the survey.element.ts file that exhibits the related adjustments:

// 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;
  };

  personal openUnsavedChangesDialog(): Observable {
    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '26.5rem',
      knowledge: { 
        dialogTitle: 'Unsaved Adjustments', 
        dialogMessageLine1: 'You've gotten unsaved adjustments.',
        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 so much happening on this little technique, so let’s unpack it.

The dialog reference that we injected through the constructor gives quite a few strategies, properties, and occasion hooks for working with it, a very powerful of which being the open() technique. 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 are able to do no matter processing we have to do after the dialog is closed. In our case, we don’t must do something however cross alongside the worth returned by the dialog. That will get set by the 2 buttons within the footer through the certain [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 top results of in the present day’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 how you can use the MatDialog, probably the most complicated, and but most versatile Angular Materials element. To try this, we changed the usual JavaScript affirm dialog that we carried out within the Stopping Knowledge Loss In Angular Purposes utilizing a CanDeactivate Route Guard demo with a MatDialog.