unimitt v0.0.4
Unimitt
Tiny 600b functional event emitter / pubsub.
This fork extends mitt to add support for randomized one-to-one pub-sub.
- Microscopic: weighs less than 600 bytes gzipped
- Useful: a wildcard
"*"
event type listens to all events - Familiar: same names & ideas as Node's EventEmitter
- Functional: methods don't rely on
this
- Great Name: somehow unimitt wasn't taken
Unimitt was made for the browser, but works in any JavaScript runtime. It has no dependencies and supports IE9+.
Table of Contents
Install
This project uses node and npm. Go check them out if you don't have them locally installed.
$ npm install --save unimitt
Then with a module bundler like rollup or webpack, use as you would anything else:
// using ES6 modules
import unimitt from 'unimitt'
// using CommonJS modules
var unimitt = require('unimitt')
The UMD build is also available on unpkg:
<script src="https://unpkg.com/unimitt/dist/unimitt.umd.js"></script>
You can find the library on window.unimitt
.
Usage
import unimitt from 'unimitt'
const emitter = unimitt()
// listen to an event
emitter.on('foo', e => console.log('foo', e) )
// listen to all events
emitter.on('*', (type, e) => console.log(type, e) )
// fire an event
emitter.emit('foo', { a: 'b' })
// clearing all events
emitter.all.clear()
// working with handler references:
function onFoo() {}
emitter.on('foo', onFoo) // listen
emitter.off('foo', onFoo) // unlisten
Typescript
Set "strict": true
in your tsconfig.json to get improved type inference for unimitt
instance methods.
import unimitt from 'unimitt';
type Events = {
foo: string;
bar?: number;
};
const emitter = unimitt<Events>(); // inferred as Emitter<Events>
emitter.on('foo', (e) => {}); // 'e' has inferred type 'string'
emitter.emit('foo', 42); // Error: Argument of type 'number' is not assignable to parameter of type 'string'. (2345)
Alternatively, you can use the provided Emitter
type:
import unimitt, { Emitter } from 'unimitt';
type Events = {
foo: string;
bar?: number;
};
const emitter: Emitter<Events> = unimitt<Events>();
API
Table of Contents
unimitt
Unimitt: Tiny (~600b) functional event emitter / pubsub.
Returns Unimitt
all
A Map of event names to registered handler functions.
groups
A map of event names, to queue groups, to registered handler functions.
on
Register an event handler for the given type.
Parameters
type
(string | symbol) Type of event to listen for, or'*'
for all eventshandler
Function Function to call in response to given eventgroup
any?
off
Remove an event handler for the given type.
If handler
is omitted, all handlers of the given type are removed, including groups, unless a group is
specified, in which case all handlers for that group are removed (but not other groups, or non-group handlers).
Parameters
type
(string | symbol) Type of event to unregisterhandler
from ('*'
to remove a wildcard handler)handler
Function? Handler function to removegroup
any?
emit
Invoke all handlers for the given type.
If present, '*'
handlers are invoked after type-matched handlers.
Note: Manually firing '*' handlers is not supported.
Parameters
type
(string | symbol) The event type to invokeevt
Any? Any value (object is recommended and powerful), passed to each handler
Contribute
First off, thanks for taking the time to contribute! Now, take a moment to be sure your contributions make sense to everyone else.
Reporting Issues
Found a problem? Want a new feature? First of all see if your issue or idea has already been reported. If don't, just open a new clear and descriptive issue.
Submitting pull requests
Pull requests are the greatest contributions, so be sure they are focused in scope, and do avoid unrelated commits.
- Fork it!
- Clone your fork:
git clone https://github.com/<your-username>/unimitt
- Navigate to the newly cloned directory:
cd unimitt
- Create a new branch for the new feature:
git checkout -b my-new-feature
- Install the tools necessary for development:
npm install
- Make your changes.
- Commit your changes:
git commit -am 'Add some feature'
- Push to the branch:
git push origin my-new-feature
- Submit a pull request with full remarks documenting your changes.