Extended Ecosystem
Service Workers & PWAs

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.

Learn more in The App Shell Model.

  1. Prepare the application

    Do this with the following Angular CLI command:

    ng new my-app --routing

    For an existing application, you have to manually add the Router and defining a <router-outlet> within your application.

  2. Create the application shell

    Use the Angular CLI to automatically create the application 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.

    ├── 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
    ng build --configuration=development

    Or to use the production configuration.

    ng build

    To verify the build output, open dist/my-app/browser/index.html. Look for default text app-shell works! to show that the application shell route was rendered as part of the output.