Structure Your Application

In the previous section, we learned the fundamentals of NextKit's architecture and the application layers.

In this section, we learn how to structure your application in practical terms with an example. For example, your application has an entity "events": how do we add this entity to a NextKit application?

In short, this is how we add a new entity to the application:

1. First, we add a new folder to lib. If the entity is "event", we add lib/events.
2. Then, we add the components of the event domain to app/dashboard/[organization]/events/components
3. Finally, we add the pages of the event domain to app/dashboard/[organization]/events

bash- app
  - lib
    - events
      - types
        - event-model.ts
        - ...
      - hooks
        - use-fetch-events.ts
        - use-create-event.ts
        - ...
      - utils
        - create-event-model.ts
  - app
    - dashboard
      - [organization]
        - events
          components
            - events
              - EventsContainerComponent.tsx
              - ...
          - page.tsx
          - $event.tsx

NB: In the Next.js App Directory, you can also add the lib folders within the app folder. For example, you can add app/dashboard/[organization]/events/lib instead of lib/events.

1) Adding the entity's business domain

We will add various business logic units in the lib/events folder, such as types, custom hooks, API calls, factories, functions, utilities, etc.

Types

First, we define a type EventModel at lib/events/types/event-model.ts:

tsexport interface EventModel {
  name: string;
  description: string;
}

Adding interfaces is optional, but it's a good practice to define the shape of your data.

Custom Hooks

For example, let's write a custom hook that retrieves a list of "events" from a Postgres table.

We create a file at lib/events/hooks/use-fetch-events.ts with the following content:

tsexport function useFetchEvents(
  organizationId: number
) {
  const client = useSupabase();
  const key = [`events`, organizationId];
 
  return useQuery(key, async () => {
    const { data, error } client
      .from('events')
      .select('*')
      .eq('organization_id', organizationId);
 
    if (error) {
      throw error;
    }
 
    return data;
  })
}

Good! We have a way to fetch our events, but we have to use it somewhere: to do so, let's create a component EventsListContainer.

2) Components

As said before, we add React components that belong to the "events" domain to components/events.

In the component below, we will fetch a list of events with useFetchEvents:

tsximport { useFetchEvents } from '~/lib/events/hooks/use-fetch-events';
import Alert from `@/components/ui/Alert`;
 
const EventsListContainer: React.FC = () => {
  const { data: events, isLoading, error } = useFetchEvents();
 
  if (isLoading) {
    return <p>Loading Events...</p>
  }
 
  if (error) {
    return (
      <Alert type='error'>
        Ops, we encountered an error!
      </Alert>
    );
  }
 
  return (
    <div>
      {events.map(event => {
        return (
          <div key={event.name}>
            <p>{event.name}</p>
            <p>{event.description}</p>;
          </div>
        );
      })}
    </div>
  )
};
 
export default EventsListContainer;

3) Routes

Finally, we can add the events component EventsListContainer to a page. To do so, let's create a page component at app/dashboard/[organization]/events/page.tsx:

tsximport EventsListContainer from '~/app/dashboard/[organization]/events/components/EventsListContainer';
 
const EventsPage: React.FC = () => {
  return (
     <EventsListContainer />
  );
};
 
export default EventsPage;

🎉 That's it! We have now built a nicely structured "events" domain.