Prefetching doesn't work for lazy routes

Prefetching doesn’t work for me when I load a lazy route with links to other lazy routes.

Here is my config:

@NgModule({
  imports: [SharedModule, AppRoutingModule]
})
export class AppModule {}

@NgModule({
  imports: [
    RouterModule.forRoot(routes, {
      onSameUrlNavigation: 'reload',
      relativeLinkResolution: 'corrected',
      preloadingStrategy: QuicklinkStrategy
    })
  ],
  exports: [RouterModule]
})
export class AppRoutingModule {}

@NgModule({
  imports: [CommonModule, RouterModule, QuicklinkModule],
  exports: [CommonModule, RouterModule, QuicklinkModule]
})
export class SharedModule {}

@NgModule({
  imports: [
    SharedModule,
    RouterModule.forChild(lazyModuleRoutes)
  ]
})
export class LazyModule {}

I tried to debug the problem and it appeared that PrefetchRegistry#shouldPrefetch method is being called with proper urls but this.trees array is empty here: https://github.com/mgechev/ngx-quicklink/blob/d7bd54c0c8b34822efee208b8631a39fc268d436/src/prefetch-registry.service.ts#L20-L23

I added a few console.logs after that:

• Added console.log("created a registry"); to the constructor of PrefetchRegistry: https://github.com/mgechev/ngx-quicklink/blob/d7bd54c0c8b34822efee208b8631a39fc268d436/src/prefetch-registry.service.ts#L12-L14

• Added console.log("added a tree", tree.toString(), 'this.trees.length =', this.trees.length); to the PrefetchRegistry#add method: https://github.com/mgechev/ngx-quicklink/blob/d7bd54c0c8b34822efee208b8631a39fc268d436/src/prefetch-registry.service.ts#L16-L18

And here are the results:

created a registry
created a registry
added a tree /path-to-lazy-route-on-screen this.trees.length = 1
should prefetch called for /path-to-lazy-route-on-screen this.trees.length = 0

Note that PrefetchRegistry was created twice and seems like shouldPrefetch method was called on the wrong instance with empty trees array.

[th0r]

@mgechev it works now! Thanks a lot!

[mgechev]

You can try ngx-quicklink@0.1.4.