Writing data to Firestore

Similarly to reading data from Firestore, we may want to create a `custom hook`` also when we write, update or delete data.

Assuming we have an entity called tasks, and we want to create a hook to create a new Task, we can do the following.

1. First, we create a new hook at lib/tasks/hooks/use-create-task.ts
2. We add the tasks collection name to lib/firestore-collections
3. Wrap the addDoc function from Firestore within a useCallback hook

import { TASKS_COLLECTION } from '~/lib/firestore-collections';

function useCreateTask() {
  const firestore = useFirestore();
  const tasksCollection = collection(firestore, TASKS_COLLECTION);

  return useCallback(
    (task: Task) => {
      return addDoc(tasksCollection, task);
    },
    [tasksCollection]
  );
}

And now, we could use this hook within a component:

function Component() {
  const createTask = useCreateTask();

  return <MyForm onSubmit={task => createTask(task)} />
}

Let's take a look at a complete example of a form that makes a request using the hook above:

const CreateTaskForm = () => {
  const createTask = useCreateTask();
  const { setLoading, state } = useRequestState();
  const router = useRouter();
  const organization = useCurrentOrganization();
  const organizationId = organization?.id as string;

  const onCreateTask: FormEventHandler<HTMLFormElement> = useCallback(
    async (event) => {
      event.preventDefault();

      const target = event.currentTarget;
      const data = new FormData(target);
      const name = data.get('name') as string;
      const dueDate = data.get('dueDate') as string;

      setLoading(true);

      const task = {
        organizationId,
        name,
        dueDate,
        description: ``,
        done: false,
      };

      await toaster.promise(createTask(task), {
        success: `Task created!`,
        error: `Ops, error!`,
        loading: `Creating task...`,
      });

      await router.push(`/tasks`);
    },
    [router, createTask, organizationId, setLoading]
  );

  return (
    <div>
      <form onSubmit={onCreateTask}>
        <div className={'flex flex-col space-y-3'}>
          <TextField.Label>
            Name
            <TextField.Input
              required
              name={'name'}
              placeholder={'ex. Launch on IndieHackers'}
            />
            <TextField.Hint>Hint: whatever you do, ship!</TextField.Hint>
          </TextField.Label>

          <TextField.Label>
            Due date
            <TextField.Input
              required
              defaultValue={getDefaultDueDate()}
              name={'dueDate'}
              type={'date'}
            />
          </TextField.Label>

          <div
            className={
              'flex flex-col space-y-2 md:space-y-0 md:space-x-2' +
              ' md:flex-row'
            }
          >
            <Button loading={state.loading}>
              <If condition={state.loading} fallback={<>Create Task</>}>
                Creating Task...
              </If>
            </Button>

            <Button color={'transparent'} href={'/tasks'}>
              Go back
            </Button>
          </div>
        </div>
      </form>
    </div>
  );
};

function getDefaultDueDate() {
  const date = new Date();
  const year = date.getFullYear();
  const month = pad(date.getMonth() + 1);
  const day = pad(date.getDate() + 1);

  return `${year}-${month}-${day}`;
}

function pad(n: number) {
  return n < 10 ? `0${n}` : n.toString();
}

export default CreateTaskForm;