Angular 2 - Lifecycle hooks for lazy loaded modules

user_1093774 0
Viewed 5429

I am in the process of developing an application using lazy loaded Angular modules.

I have a simple question:

Is it possible to catch an event when a module is loaded?

For example OnInit. This link explains life cycle hooks but it is only for components: Lifecycle hooks for components

I cant find any documentation that explains how to hook in for modules.

Does someone have an idea of how to solve this?

Thanks

angular components lifecycle module javascript
2 Answers

The constructor of the lazy loaded module should do that

@NgModule({...})
export class MyLazyModule {
  constructor(/* service injection here if required */) {
    console.log('lazy module loaded');
  }
}
user_2174080

There are two router events that you can use: RouteConfigLoadStart and RouteConfigLoadEnd. Also you can use LoadChildrenCallback. These might not do exactly what you want, but still can be helpful.

Also you can use the following trick:

@NgModule({
    imports        : [BrowserModule, FormsModule, RouterModule, ROUTING],
    providers      : [
        {provide: CustomService, useClass: CustomService},
        ...
    ]
})
export class AppModule implements OnInit
{
    //force CustomService service creation or inject other app service,
    // so use can use it to fire event or do smth.
    constructor(handler:CustomService)
    {
        console.log('handler', handler);
        handler.fire('module created');
    }
}
user_4912650
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