George Kalpakas 43ecf8a77b feat(platform-server): allow shimming the global env sooner ()
`@angular/platform-server` provides the foundation for rendering an
Angular app on the server. In order to achieve that, it uses a
server-side DOM implementation (currently [domino][1]).

For rendering on the server to work as closely as possible to running
the app on the browser, we need to make DOM globals (such as `Element`,
`HTMLElement`, etc.), which are normally provided by the browser,
available as globals on the server as well.

Currently, `@angular/platform-server` achieves this by extending the
`global` object with the DOM implementation provided by `domino`. This
assignment happens in the [setDomTypes()][2] function, which is
[called in a `PLATFORM_INITIALIZER`][3]. While this works in most cases,
there are some scenarios where the DOM globals are needed sooner (i.e.
before initializing the platform). See, for example,  and 
for more details on such issues.

This commit provides a way to solve this problem by exposing a
side-effect-ful entry-point (`@angular/platform-server/init`), that
shims the `global` object with DOM globals. People will be able to
import this entry-point in their server-rendered apps before
bootstrapping the app (for example, in their `main.server.ts` file).
(See also [ (comment)][4].)

In a future update, the [`universal` schematics][5] will include such an
import by default in newly generated projects.

[1]: https://www.npmjs.com/package/domino
[2]: https://github.com/angular/angular/blob/0fc8466f1be392917e0c/packages/platform-server/src/domino_adapter.ts#L17-L21
[3]: https://github.com/angular/angular/blob/0fc8466f1be392917e0c/packages/platform-server/src/server.ts#L33
[4]: https://github.com/angular/angular/issues/39950#issuecomment-747598403
[5]: https://github.com/angular/angular-cli/blob/cc51432661eb4ab4b6a3/packages/schematics/angular/universal

PR Close 
2021-02-12 08:55:25 -08:00
..