# Events

Using the `.on()`, `.once()` and `.off()` methods you can subscribe and unsubscribe to events.

- All of above mentioned methods are available on `Taggd` and `Tag` instances.
- To subscribe to an event for _all_ tags, subscribe to that event on the `Taggd` instance.

For example:

```js
const image = document.getElementById('my-image');
const taggd = new Taggd(image);

// Prevent adding tags
taggd.on('taggd.tag.add', (tag) => {
  // Some events can be prevented by returning false (see tables below)
  return false;
});

// This tag isn’t added because of above event handler
taggd.add(new Taggd.Tag(..., ...));
```

## Taggd Events

The table below lists all available tables for a `Taggd` instance.

All `taggd.tag.*` event handlers receive the following arguments:

1. `Taggd` instance
2. `Tag` instance

All other events receive the following arguments:

1. `Taggd` instance

| Event                  | Triggered                            | Is preventable by returning `false` |
|------------------------|--------------------------------------|-------------------------------------|
| `taggd.destroy`        | before destroying a `Taggd` instance | yes                                 |
| `taggd.editor.enable`  | before enable editor mode            | yes                                 |
| `taggd.editor.disable` | before disabling editor mode         | yes                                 |
| `taggd.tag.add`        | before adding a tag                  | yes                                 |
| `taggd.tag.added`      | after adding a tag                   | no                                  |
| `taggd.tag.delete`     | before deleting a tag                | yes                                 |
| `taggd.tag.deleted`    | after deleting a tag                 | no                                  |
| `taggd.tag.show`       | before showing a tag                 | yes                                 |
| `taggd.tag.shown`      | after showing a tag                  | no                                  |
| `taggd.tag.hide`       | before hiding a tag                  | yes                                 |
| `taggd.tag.hidden`     | after hiding a tag                   | no                                  |
| `taggd.tag.change`     | before changing a tag                | yes                                 |
| `taggd.tag.changed`    | after changing a tag                 | no                                  |


## Tag Events

The table below lists all available tables for a `Tag` instance.

All `taggd.tag.*` event handlers receive the following argument:

1. `Tag` instance

| Event                  | Triggered                            | Is preventable by returning `false` |
|------------------------|--------------------------------------|-------------------------------------|
| `taggd.tag.delete`     | before deleting a tag                | yes                                 |
| `taggd.tag.show`       | before showing a tag                 | yes                                 |
| `taggd.tag.shown`      | after showing a tag                  | no                                  |
| `taggd.tag.hide`       | before hiding a tag                  | yes                                 |
| `taggd.tag.hidden`     | after hiding a tag                   | no                                  |
| `taggd.tag.change`     | before changing a tag                | yes                                 |
| `taggd.tag.changed`    | after changing a tag                 | no                                  |