Deployment 3.1

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Deploying an AngularDart web app is similar to deploying any other web app, except that you first need to compile the app to JavaScript. This page describes how to compile your app—with tips for making it smaller and faster—and points you to resources for serving the app.

Building your app

Use pub build to build your app, compiling it to JavaScript and generating all the assets you need for deployment. When you use the default pub settings, you get a minified JavaScript file that’s reasonably small, thanks to the dart2js compiler’s support for tree shaking.

With a little extra work, you can make your deployable app smaller, faster, and more reliable.

Compile using pub build

To create a deployable version of your app, use the pub build command. By default, this command uses dart2js and the angular2 transformer to produce the JavaScript file that implements your app. Here’s what happens when you use pub build with the default settings:

  • The deployable files appear under your app’s build/web directory.
  • The dart2js compiler runs in release mode, producing minified JavaScript in the file build/web/main.dart.js.
  • As long as dart_to_js_script_rewriter is the last transformer in your app’s pubspec.yaml file (or next to last, if you’re using the $dart2js transformer), the build/web/index.html file is rewritten to link to main.dart.js instead of main.dart.

For more information, see the documentation for pub build, or search for pubspec in the starter app discussion.

Use dart2js flags to produce better JavaScript

Google’s apps often use the following dart2js options:

  • --trust-type-annotations
  • --trust-primitives
  • --fast-startup

Test your apps before deploying with these options! If your app runs under dart2js in checked mode or under dartdevc, then we recommend using --trust-type-annotations. However, --trust-primitives can have unexpected results (even in well-typed code) if your data isn’t always valid. Build your app both with and without --fast-startup, so you can judge whether the speedup is worth the increase in JavaScript size.

You can specify dart2js options in your app’s pubspec using the $dart2js transformer, which should be the last transformer in the pubspec file:

- ...all other transformers...
- $dart2js:
    commandLineOptions: [--trust-type-annotations, --trust-primitives, --fast-startup]

For more information, see the dart2js size and speed options and the documentation on configuring the dart2js transformer for pub.

Make your app smaller, faster, and more reliable

The following steps are optional, but they can help make your app more reliable and responsive.

Use the pwa package to make your app work offline

The pwa package simplifies the task of making your app work with limited or no connectivity. For information on using this package, see Making a Dart web app offline-capable: 3 lines of code.

Use deferred loading to reduce your app’s initial size

You can use Dart’s support for deferred loading to reduce your app’s initial download size, as described in Lazy loading with Angular Dart.

Follow best practices for web apps

The usual advice for web apps applies to AngularDart web apps. Here are a few resources:

Remove unneeded build files

The angular2 transformer currently produces many intermediate files (with suffixes like .ng_meta.json and .ng_summary.json) that you don’t need when deploying your app. To remove these files, you can use a command like the following:

# From your app's top directory:
$ find build -name "*.ng_*.json" -exec rm {} +

Serving your app

You can serve your AngularDart app just like you’d serve any other web app. This section points to tips for serving Angular apps, as well as Dart-specific resources to help you use GitHub Pages or Firebase to serve your app.

Angular-specific tips

For information on changes you might have to make to the server, see the Server configuration section of the Angular TypeScript deployment documentation.

GitHub Pages

If your app doesn’t use routing or require server-side support, you can serve the app using GitHub Pages. The peanut package is an easy way to automatically produce a gh-pages branch for any Dart web app.

The startup_namer example is hosted using GitHub Pages. Its files are in the gh-pages branch of the filiph/startup_namer repo and were built using peanut.


For a walk-through of using Firebase to serve a chat app, see Build a Real-Time Chat Web App with Dart, Angular 2, and Firebase 3.

Other resources: