jemjs

JEM

What is JEM?

JEM stands for **J**avaScript **E**vent**M**anager. It's a small tool for handling custom events across multiple modules.

JEM provides minimal functionality helping you to keep cleaner codebase with less dependencies.

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How does it work?

Every event has a unique identifier - it's name. You can subscribe endless functions to an event. If the event gets emitted all subscribers will be called.

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Getting started

Installation

    npm i jemjs --save-dev

    import { JEM } from jemjs;

Reference

JEM.On(eventName, ...listener)

Subscribes one or multiple listeners to an event.

    JEM.On(
        'eventName', 
        () => { /* your code here */ }
    );

Mutliple listeners can subscribe to On too.

 
    JEM.On(
        'eventName', 
        () => { /* _your code here */ }, 
        (x) => { /* Arguments can be provided by JEM.Emit. */ }
    );
 

JEM.Once(eventName, ...listener)

Subscribes one or multiple listeners to an event. Listenery bound with Once will be dispatched after the first call.

    JEM.Once(
        'incrementCount', 
        () => { /* your code here */ }
    );

Multiple listeners can subscribe to Once too.

 
    JEM.Once(
        'increment', 
        () => { /* _your code here */ }, 
        (x) => { /* Arguments can be provided by JEM.Emit. */ }
    );
 

JEM.Emit(eventName[, ...listenerArgs])

Calls all listeners subscribed to the specified event.

    // Call all subscribers for the event "eventName"
    JEM.Emit('eventName');
 
    //Works with arguments too.
    JEM.Emit('eventName', 1337);
 
    //Even with a lot arguments
    JEM.Emit('eventName', 1, 2, 3, 4, 'a', 'b');
 

JEM.Dispatch

Removes a listener or a complete event.

    JEM.Dispatch('eventName'); // Removes the specified event. All listeners are gone.
 
    function increment(x) {
        return ++x;
    }
 
    JEM.Dispatch('eventName', increment); //Removes this listener.

JEM.Clear

Removes all events (and all listeners).

    JEM.Clear();

JEM.Isolate

Creates a new isolated JEM-scope. By default theres only one global JEM-scope. Isolated scopes provided the same functionality like the global JEM-scope except the Isolate function is not present.

    const isolatedJEM = JEM.Isolate();