NGRX Workshop Notes - Folder Structure
Alfredo Perez
Posted on April 3, 2020
Following the LIFT principle:
- Locating our code is easy
- Identify code at a glance
- Flat file structure for as long as possible
- Try to stay DRY - don’t repeat yourself
Key Takeaways
- Put state in a shared place separate from features
- Effects, components, and actions belong to features
- Some effects can be shared
- Reducers reach into modules’ action barrels
Folder structure followed in the workshop
├─ books\
│ actions\
│ books-api.actions.ts
│ books-page.actions.ts
│ index.ts // Includes creating names for the exports
│ books-api.effects.ts
│
├─ shared\
│ state\
│ {feature}.reducer.ts // Includes state interface, initial interface, reducers and local selectors
│ index.ts
│
- The index file in the actions folder was using action barrels like the following:
import * as BooksPageActions from "./books-page.actions";
import * as BooksApiActions from "./books-api.actions";
export { BooksPageActions, BooksApiActions };
- This made easier and more readable at the time of importing it:
import { BooksPageActions } from "app/modules/book-collection/actions";
Folder structure followed in example app from @ngrx
├─ books\
│ actions\
│ books-api.actions.ts
│ books-page.actions.ts
│ index.ts // Includes creating names for the exports
│ effects\
| books.effects.spec.ts
| books.effects.ts
| models\
| books.ts
│ reducers\
| books.reducer.spec.ts
| books.reducer.ts
| collection.reducer.ts
| index.ts
│
├─ reducers\
│ index.ts /// Defines the root state and reducers
│
- The index file under the reducers folder is in charge of setting up the reducer and state
import * as fromSearch from '@example-app/books/reducers/search.reducer';
import * as fromBooks from '@example-app/books/reducers/books.reducer';
import * as fromCollection from '@example-app/books/reducers/collection.reducer';
import * as fromRoot from '@example-app/reducers';
export const booksFeatureKey = 'books';
export interface BooksState {
[fromSearch.searchFeatureKey]: fromSearch.State;
[fromBooks.booksFeatureKey]: fromBooks.State;
[fromCollection.collectionFeatureKey]: fromCollection.State;
}
export interface State extends fromRoot.State {
[booksFeatureKey]: BooksState;
}
/** Provide reducer in AoT-compilation happy way */
export function reducers(state: BooksState | undefined, action: Action) {
return combineReducers({
[fromSearch.searchFeatureKey]: fromSearch.reducer,
[fromBooks.booksFeatureKey]: fromBooks.reducer,
[fromCollection.collectionFeatureKey]: fromCollection.reducer,
})(state, action);
}
- The index file under
app/reducers/index.ts
defines the meta-reducers, root state, and reducers
/**
* Our state is composed of a map of action reducer functions.
* These reducer functions are called with each dispatched action
* and the current or initial state and return a new immutable state.
*/
export const ROOT_REDUCERS = new InjectionToken<
ActionReducerMap<State, Action>
>('Root reducers token', {
factory: () => ({
[fromLayout.layoutFeatureKey]: fromLayout.reducer,
router: fromRouter.routerReducer,
}),
});
Personally, I like how the example-app
is organized. One of the things that I will add is to have all the folders related to ngrx in a single folder:
├─ books\
│ store\
│ actions\
│ books-api.actions.ts
│ books-page.actions.ts
│ index.ts // Includes creating names for the exports
│ effects\
| books.effects.spec.ts
| books.effects.ts
| models\
| books.ts
│ reducers\
| books.reducer.spec.ts
| books.reducer.ts
| collection.reducer.ts
| index.ts
│
├─ reducers\
│ index.ts /// Defines the root state and reducers
│
💖 💪 🙅 🚩
Alfredo Perez
Posted on April 3, 2020
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