Add client-side entry point script.

[schultek]

Problem

Currently there is no option to run code on the client before mounting a @client component, since the client-side entrypoint is transparently auto-generated. When using multiple client components, there is no single global main function.

Additionally, developers cannot wrap their client components in some other component, like a ProviderScope or similar. This makes sharing state between client components impossible without using global state.

Proposed Solution

Allow the definition of a client-side entrypoint file, e.g. main.client.dart, where the user manually calls runApp() on the client to start the hydration. Similar to defaultJasprOptions for the server, there would have to be a generated configuration or component that encapsulates the @client component registration. An API could look like this:

// This file is 'lib/main.client.dart'

import 'package:jaspr/browser.dart';

// Generated client options
import 'client_options.g.dart';

void main() {
  // Whatever code here.
  { }

  runApp(
    // Wrap in arbitrary component
    MyWrappingComponent( 
      child: ClientApp( // This would be a new core framework component
        options: defaultClientOptions, // This is imported from the generated file.
      ),
    ),
  );
}

This would replace the auto-generated web/main.clients.dart file.

---

When implementing this feature, the natural thing would also be to align the definition of server entrypoints to use a similar schema:

• lib/<...>.server.dart as the filename convention
• lib/server_options.g.dart as the generated options file.

This would also allow the framework and tooling to auto-detect entrypoint files without needing to configure them in pubspec.yaml.

[parlough]

This all makes sense to me and seems like a good idea.

Would manual hydration also be able to go in this file?

[schultek]

This should also work for manual hydration and even client mode. But it's not meant to be mandatory in these cases.

[schultek]

I've opted for the following:

- main.server.dart (prev main.dart)
- main.server.g.dart (prev jaspr_options.dart)
- main.client.dart (new)
- main.client.g.dart (new)

This keeps the files in nice order and allows for file nesting inside the editor.

I'm also planning to rename ' package:jaspr/browser.dart' to 'package:jaspr/client.dart' to keep everything consistent.