Creating a single page app (SPA) 

In this section, we will learn about some best practices which can be used to create a single page app. Some of them are listed next:

• Keep the root module and root component as lean as possible. Program routing as a separate module and import the same in AppModule.
• Design and develop features as separate modules.
• Use route guards to provide controlled access to one or more components.

Lean root module

It is recommended to keep the top-level root module, routing module, and the root/shell component as lean as possible. This, essentially, means some of the following:

• The root module should import the root-level routing module, root components, and feature modules. The following code represents the same. Make a note of the feature modules, such as DocModule, AuthModule, and AppRoutingModule:

        import { NgModule }      from '@angular/core';
        import { BrowserModule } from '@angular/platform-browser';
        import { FormsModule }   from '@angular/forms...