App shell pattern

The App shell pattern is a way to render a portion of your application using a route at build time. It can improve the user experience by quickly launching a static rendered page (a skeleton common to all pages) while the browser downloads the full client version and switches to it automatically after the code loads.

This gives users a meaningful first paint of your application that appears quickly because the browser can render the HTML and CSS without the need to initialize any JavaScript.

<docs-workflow> <docs-step title="Prepare the application"> Do this with the following Angular CLI command:

shell

ng new my-app

For an existing application, you have to manually add the Router and defining a <router-outlet> within your application. </docs-step> <docs-step title="Create the application shell"> Use the Angular CLI to automatically create the application shell.

shell

ng generate app-shell

For more information about this command, see App shell command.

The command updates the application code and adds extra files to the project structure.

text

src
├── app
│ ├── app.config.server.ts # server application configuration
│ └── app-shell # app-shell component
│   ├── app-shell.component.html
│   ├── app-shell.component.scss
│   ├── app-shell.component.spec.ts
│   └── app-shell.component.ts
└── main.server.ts # main server application bootstrapping

<docs-step title="Verify the application is built with the shell content">

shell

ng build --configuration=development

Or to use the production configuration.

shell

ng build

To verify the build output, open <code class="no-auto-link">dist/my-app/browser/index.html</code>. Look for default text app-shell works! to show that the application shell route was rendered as part of the output. </docs-step> </docs-workflow>