Types of State:

• Server state
  • stored on the server and is provided via, e.g. REST endpoint
• Persistent state
  • server state stored on the client
• Client state
  • state stored on the client
• URL and Router state
• Transient Client state
  • not represent in the URL
• Local UI state

  ______________
 |              |
 | Server state |
 |______________|
         |
         V
 _________________      ______________     __________________
|                 |    |              |   |                  |
| Persisten state |    | Client state |   | Transient Client | 
|_________________|    |______________|   |      state       | 
              \              /            |__________________|
               \            /               
        _________________________           ________________
       |                         |         |                | 
       |       URL / Router      |         | Local UI state |
       |_________________________|         |________________|

Rules:

• Separate services/computation from state management
• Optimistic updates require separate actions to deal with errors
• Use immutable data for persistent and client state

Angular Notes:

• routing.ts (routing for modules) must be imported after other modules in the 'imports' field of app.module.ts
• <submodule>.routing.ts (routing for components of each module) is required

NGXS Notes:

• in NGXS state class any reduce function (with @Action) must not be static
• store.select will return all (current) states in the store
• the name of each state is defined by the 'name' field of @State
• to allow the injection of NGXS store, NgxsModule.forRoot([<StateClass1>, <StateClass2>]) must be imported in *.module.ts