Study Angular 11 MatDialog Fundamentals

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Of all of the Angular Materials parts, the MatDialog simply stands out as 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 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 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’ll now add MatDialog to the checklist:

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() technique accepts a element to indicate within the physique of the dialog. You could be tempted to create the element as a baby to the one that may name it, nevertheless it could be sensible to assume twice earlier than doing in order we might wish to reuse the identical dialog somewhere else 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.element.ts file, we’ll modify the constructor to just accept a reference to the dialog in addition to the information that we are going to move 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.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:

<div class="dialog-header accent-background">
  <span class="dialog-header-title">{{knowledge.dialogTitle}}</span>
</div>
<div class="dialog-content">
  <p>{{knowledge.dialogMessageLine1}}<br/>
  {{knowledge.dialogMessageLine2}}</p>
</div>
<div class="dialog-footer">
  <button class="standard-button dialog-button" mat-raised-button [mat-dialog-close]="false" cdkFocusInitial>{{knowledge.noButtonText}}</button>
    
  <button mat-raised-button shade="main" [mat-dialog-close]="true">{{knowledge.yesButtonText}}</button>
</div>

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 answerable for exhibiting 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

@Part({
  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<boolean> {
    return this.ngFormRef.soiled
      ? this.openUnsavedChangesDialog()
      : true;
  };

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

    return dialogRef.afterClosed();
  }
}

The openUnsavedChangesDialog() Technique Defined

There’s loads occurring 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 move 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 move 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:

<div class="dialog-footer">
  <button class="standard-button dialog-button" mat-raised-button [mat-dialog-close]="false" cdkFocusInitial>{{knowledge.noButtonText}}</button>
  &nbsp;&nbsp;
  <button mat-raised-button shade="main" [mat-dialog-close]="true">{{knowledge.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 at this time’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 realized the way to use the MatDialog, probably the most advanced, and but most versatile Angular Materials element. To try this, we changed the usual JavaScript affirm dialog that we carried out within the Stopping Information Loss In Angular Purposes utilizing a CanDeactivate Route Guard demo with a MatDialog.