Before and After Lifecycle Functions

All events expose an identical interface with two functions that can be handled by the plugin and responsible for a different step in the lifecycle of the event. One for “before” the event is emitted and another for “after” the event is emitted.

export interface PluginEventType<T extends EventParams> {
  before?: PluginBeforeEvent<T>;
  after?: PluginAfterEvent<T>;
}

For each event, the type of EventParams is different, providing access to relevant data for the specific event.

export interface EventParams {}

export type PluginBeforeEvent<T extends EventParams> = (
  dsgContext: DsgContext,
  eventParams: T
) => Promisable<T>;

export type PluginAfterEvent<T extends EventParams> = (
  dsgContext: DsgContext,
  eventParams: T,
  modules: ModuleMap
) => Promisable<ModuleMap>;

In the before and after functions, we have an access to the context and the event params. The context is used to gather common parts between events. The event params manipulate the default behavior by passing different values.

In the after function, we also have access to the generated modules. An example of using this parameter is when you want to restructure the generated modules in a different folder structure.

Cautionary Guidelines

1. In the after function, avoid unintentionally overriding the entire generated file. Opt for smaller changes instead.
2. In the before function, take care when modifying templates to not unintentionally affect code generation.
3. In the before function, only choose skipDefaultBehavior if skipping code generation entirely, including default generation, is intended.