75 lines
1.3 KiB
Markdown
75 lines
1.3 KiB
Markdown
# Emitter [](https://travis-ci.org/component/emitter)
|
|
|
|
Event emitter component.
|
|
|
|
## Installation
|
|
|
|
```
|
|
$ component install component/emitter
|
|
```
|
|
|
|
## API
|
|
|
|
### Emitter(obj)
|
|
|
|
The `Emitter` may also be used as a mixin. For example
|
|
a "plain" object may become an emitter, or you may
|
|
extend an existing prototype.
|
|
|
|
As an `Emitter` instance:
|
|
|
|
```js
|
|
var Emitter = require('emitter');
|
|
var emitter = new Emitter;
|
|
emitter.emit('something');
|
|
```
|
|
|
|
As a mixin:
|
|
|
|
```js
|
|
var Emitter = require('emitter');
|
|
var user = { name: 'tobi' };
|
|
Emitter(user);
|
|
|
|
user.emit('im a user');
|
|
```
|
|
|
|
As a prototype mixin:
|
|
|
|
```js
|
|
var Emitter = require('emitter');
|
|
Emitter(User.prototype);
|
|
```
|
|
|
|
### Emitter#on(event, fn)
|
|
|
|
Register an `event` handler `fn`.
|
|
|
|
### Emitter#once(event, fn)
|
|
|
|
Register a single-shot `event` handler `fn`,
|
|
removed immediately after it is invoked the
|
|
first time.
|
|
|
|
### Emitter#off(event, fn)
|
|
|
|
* Pass `event` and `fn` to remove a listener.
|
|
* Pass `event` to remove all listeners on that event.
|
|
* Pass nothing to remove all listeners on all events.
|
|
|
|
### Emitter#emit(event, ...)
|
|
|
|
Emit an `event` with variable option args.
|
|
|
|
### Emitter#listeners(event)
|
|
|
|
Return an array of callbacks, or an empty array.
|
|
|
|
### Emitter#hasListeners(event)
|
|
|
|
Check if this emitter has `event` handlers.
|
|
|
|
## License
|
|
|
|
MIT
|