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    mitt
    TypeScript icon, indicating that this package has built-in type declarations

    2.1.0 • Public • Published

    mitt
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    Mitt

    Tiny 200b functional event emitter / pubsub.

    • Microscopic: weighs less than 200 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 mitt wasn't taken

    Mitt 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 mitt

    Then with a module bundler like rollup or webpack, use as you would anything else:

    // using ES6 modules
    import mitt from 'mitt'
     
    // using CommonJS modules
    var mitt = require('mitt')

    The UMD build is also available on unpkg:

    <script src="https://unpkg.com/mitt/dist/mitt.umd.js"></script>

    You can find the library on window.mitt.

    Usage

    import mitt from 'mitt'
     
    const emitter = mitt()
     
    // 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

    import mitt from 'mitt';
    const emitter: mitt.Emitter = mitt();

    Examples & Demos

    Preact + Mitt Codepen Demo
    preact + mitt preview

    API

    Table of Contents

    mitt

    Mitt: Tiny (~200b) functional event emitter / pubsub.

    Returns Mitt

    all

    A Map of event names 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 events
    • handler Function Function to call in response to given event

    off

    Remove an event handler for the given type.

    Parameters

    • type (string | symbol) Type of event to unregister handler from, or "*"
    • handler Function Handler function to remove

    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 invoke
    • evt 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>/mitt
    • Navigate to the newly cloned directory: cd mitt
    • 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.

    License

    MIT License © Jason Miller

    Install

    npm i mitt

    DownloadsWeekly Downloads

    1,550,764

    Version

    2.1.0

    License

    MIT

    Unpacked Size

    27.6 kB

    Total Files

    12

    Last publish

    Collaborators

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