downgradeModule

A helper function for creating an AngularJS module that can bootstrap an Angular module "on-demand" (possibly lazily) when a downgraded component needs to be instantiated.

Part of the upgrade/static library for hybrid upgrade apps that support AOT compilation.

It allows loading/bootstrapping the Angular part of a hybrid application lazily and not having to pay the cost up-front. For example, you can have an AngularJS application that uses Angular for specific routes and only instantiate the Angular modules if/when the user visits one of these routes.

The Angular module will be bootstrapped once (when requested for the first time) and the same reference will be used from that point onwards.

downgradeModule() requires either an NgModuleFactory, NgModule class or a function:

• NgModuleFactory: If you pass an NgModuleFactory, it will be used to instantiate a module using platformBrowser's bootstrapModuleFactory(). NOTE: this type of the argument is deprecated. Please either provide an NgModule class or a bootstrap function instead.
• NgModule class: If you pass an NgModule class, it will be used to instantiate a module using platformBrowser's bootstrapModule().
• Function: If you pass a function, it is expected to return a promise resolving to an NgModuleRef. The function is called with an array of extra Providers that are expected to be available from the returned NgModuleRef's Injector.

downgradeModule() returns the name of the created AngularJS wrapper module. You can use it to declare a dependency in your main AngularJS module.

{@example upgrade/static/ts/lite/module.ts region="basic-how-to"}

For more details on how to use downgradeModule() see Upgrading for Performance.