angular-cn/aio/content/guide/ivy.md

Opting into Angular Ivy with Angular CLI

Ivy is the code name for Angular's next-generation compilation and rendering pipeline. Starting with Angular version 8, you can choose to opt in to start using Ivy now, and help in its continuing develpment and tuning.

Starting a new project using Ivy

To start a new project with Ivy enabled, use the --enable-ivy flag with the ng new command:

ng new shiny-ivy-app --enable-ivy

The new project is automatically configured for Ivy.

• The enableIvy option is set to true in tsconfig.app.json.

{@a updating}

Updating an existing project to use Ivy

You can update an existing project to use Ivy by making the following configuration changes.

• Add the enableIvy option in the angularCompilerOptions in your project's tsconfig.app.json.

{
  "compilerOptions": { ... },
  "angularCompilerOptions": {
    "enableIvy": true
  }
}

Switching back to the current compiler

To stop using the Ivy compiler you need to undo the steps taken when updating to use Ivy.

• Set enableIvy to false in tsconfig.app.json, or remove it completely.