Model events

When creating, updating and deleting records, it can be handy to create side-effects e.g. every time a user is deleted, log this somewhere.

Happening VS Past events

Briefly, you will find in this section two types of events:

• the ones happening when a record is being created/updated/deleted
• the ones happening after a record was created/updated/deleted

Therefore, the creating event means we are looking at a record which is being created, while a created event means it's been created already.

Events

There are three types of events at the moment: creation, update and deletion.

In the following section, we assume we have created a Flight model. Read more about creating models.

Create

Flight.on('creating', () => {
  console.log('Creating a flight record');
});

Flight.on('created', (model: Flight) => {
  console.log('Created:', model.id);
});

Update

Flight.on('updating', () => {
  console.log('Updating a flight record');
});

Flight.on('updated', (model: Flight) => {
  console.log('Updated:', model.id);
});

Delete

Flight.on('deleting', () => {
  console.log('Deleting a flight record');
});

Flight.on('deleted', (model: Flight) => {
  console.log('Deleted:', model.id);
});

Using addEventListener instead of on

You have seen examples using Model.on(eventType, callback) so far yet a more common alias is available using Model.addEventListener(eventType, callback) which works exactly the same:

Flight.addEventListener('creating', () => {
  console.log('Creating a flight record');
});

Stop listening to an event

To stop listening to an event, use Model.removeEventListener:

const handleUpdate = (model: Flight) => { ... };

Flight.on('updating', handleUpdate);
Flight.removeEventListener('updating', handleUpdate);

Chaining events

Event listeners can be chained easily:

Flight.on('updating', () => {
  console.log('Updating a flight record');
}).on('updated', (model: Flight) => {
  console.log('Updated:', model.id);
});