Manage Application Dialogs with the Angular Material Dialog Component

Instructor: [00:00] to get started with Material Design dialogs, you need to include the Mat dialog module in your NG module imports.

[00:05] Next, you need to have a component that's going to serve as your dialog template. For sake of demo, I'm going to include this component and the component that's going to trigger the dialog in the same file so you can more easily see how these two interact.

[00:16] If we look at the Material Design guidelines, we can see that each dialog is generally split up into three sections, the title, content, and then actions. As such, the dialog module offers components and directives that correspond to each section. For our dialog header, we'll add an H2 and include the Mat dialog title directive. The dialog we'll be creating will be a save confirmation.

[00:35] Next, you want to wrap your main content in the Mat dialog content component. Finally, the action button sphere dialog, generally a cancel and a confirmation, should be included in the Mat dialog actions component.

[00:48] There are a couple of ways to [inaudible] or close via your dialog action buttons. The first is to inject a Mat dialog ref, which is a reference to the currently open dialog. This should be injected in the dialog component itself. You can then create a method on your dialog component.

[01:03] Here, we'll just call it close dialog which calls close on the current dialog ref, optionally passing it whatever data you choose. We can then create a click event on the button which calls our close dialog method. While this works, it's generally not necessary.

[01:19] Let's see an easier way to accomplish this same task. The code that we created within our component to close the dialog can be replicated using the Mat dialog close directive. This accepts data or can be used without for a cancel-like scenario.

[01:35] Now, we just need to trigger this dialog within our parent component. To do this, we need to inject Mat dialog into our component. Next, we'll create a method that calls dialog.open, passing in our dialog component. We'll then create a button that's going to invoke this method within our template.

[01:53] Because dialog components are created at runtime, we also need to include our dialog component in our app entry components in order for ahead of time compilation to work. Once that's done, we can test out our first dialog. Our button opens a nice Material Design-themed dialog with the title, content, and actions that dismiss the dialog.

[02:10] The dialog.open method also sets a second parameter which is settings for your dialog. This includes ways to manually set the height, width, control backdrop behavior, and pass data to your dialog.

[02:20] We updated our dialog to a delete confirmation. We want to pass the dialog the name of the item the user is wishing to delete.

[02:27] To access this data within our dialog component, we need to inject the Mat dialog data token. We'll assign this a property item type which we know will be a string. Next, we can replace the instances of item in our template with our now dynamically supplied item type. We now have a dialog that could be reused for multiple scenarios in your application.

[02:47] Now, what if you wanted to take action when the user clicks one of the buttons in the dialog? In this case for our delete dialog, we must take no action if the user clicks cancel. But we want to delete the item if the user clicks yes.

[02:57] To do this, we'll pass 1 through our Mat dialog close directive when the user clicks yes. We'll then come up to our open dialog method and assign the reference return from dialog.open to a variable. Dialogs expose an after close observable which emits the value that was passed when the dialog was closed.

[03:11] In the case of our delete, we could use merge map to make our network request once the action was received. We also want to filter out non-truthy responses which would our cancel action. Finally, we can subscribe to the observable, logging the response to make sure this is working.

[03:27] When we refresh, we'll go ahead and pull our console over. When we open our dialog and confirm, you can see our network request would be fired. Let's go ahead and clear the console. If we open again and hit cancel, nothing happens. It's worth noting that clicking the backdrop to close the dialog is also filtered out...