Share an external module between lazy loaded modules in angular2

Question

My app has components that use a heavy-weight external package (ag-grid, about 1MB) that is provided as an angular2 module (AgGridModule). I would like to load this package only when the components using it are required, so my ContentModule and all of its submodules are lazy-loaded. The whole structure looks like this:

However, when I import AgGridModule into both Submodule1 and Submodule3, it ends up being included in compiled JS twice, making both 1.chunk.js and 3.chunk.js large. I tried importing it into ContentModule, but then the submodules do not recognize the components that are included in AgGridModule, even if I list them in the exports property of ContentModule.

@NgModule({
  imports: [
    ContentRoutingModule,
    SomeOtherModule,
    AgGridModule.withComponents([])
  ],
  exports: [
    // this is the component from AgGridModule that I use
    AgGridNg2
  ]
})
export class ContentModule { }

Is there a way to share a module between lazy loaded modules, or to expose some components of an imported module to lazy loaded children?

UPD: Creating a shared module and importing it into submodules does not help, there are still two chunks with about 1MB each:

UPD2: I solved the problem temporarily by merging Submodule1 and Submodule3 into a single module.

You should add the entire AgGridModule to the exports array. You can only export declarations within your ContentModule or entire other modules — Poul Kruijt
@PierreDuc no, exporting the entire AgGridModule does not solve it, the component is still not being recognized. — Anton Poznyakovskiy
Have you tried writing AgGridModule in imports array of ContentModule? As I am implementing the same scenario and working for me. P.S. I haven't created module files for child components. — Fawkes

Poul Kruijt Poul Kruijt · Accepted Answer · 2017-01-24T12:42:51

You need to create a SharedAgGridModule:

@NgModule({
  imports: [
    AgGridModule.withComponents([])
  ],
  exports: [
    ContentModule,
    AgGridModule
  ]
})
export class SharedAgGridModule{}

Then you should import this module just for the submodules which uses AgGrid. No need to also import the ContentModule in those submodules, because it is exported in this module

Share an external module between lazy loaded modules in angular2

3 Answers