simplesignal
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    5.1.0 • Public • Published

    Simple Signal

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    This is a super-simple signals class inspired by Robert Penner's AS3Signals.

    Signals are like Events, Delegates, or Callbacks on other languages or platforms. You can create a signal that other parts of the code can "listen" to. When that signal is dispatched, all listeners are called with the passed parameters.

    SimpleSignal is created with TypeScript, but aimed to be used as a standard JavaScript library.

    Install

    npm install simplesignal

    Usage

    First, import your signal:

    // Import (JavaScript ES5)
    var SimpleSignal = require('simplesignal');
    
    // Import (JavaScript ES6 and TypeScript)
    import SimpleSignal from 'simplesignal';

    Then, you can create a signal. For example, inside a class:

    public onSomethingHappened = new SimpleSignal();

    Then other parts of the code can subscribe (listen) to that signal:

    myClassObject.onSomethingHappened.add((id) => {
        console.log("Something happened with an id of " + id);
    });

    Signals can then be dispatched with parameters:

    onSomethingHappened.dispatch("some-id");

    This will call all subscribed functions with the given parameter.

    Full reference (JS)

    // Create
    onSomethingHappened = new SimpleSignal();
    
    // Subscribe
    onSomethingHappened.add(myFunc);
    
    // Anonymous functions are, of course, fine
    onSomethingHappened.add(function() { ... });
    onSomethingHappened.add(() => { ... });
    
    // Unsubscribe
    onSomethingHappened.remove(myFunc);
    
    // Clear subscribers
    onSomethingHappened.removeAll();
    
    // Number of subscribers
    console.log(onSomethingHappened.numItems);
    
    // Dispatch
    onSomethingHappened.dispatch(...args)

    Additional TypeScript reference

    If your project already uses TypeScript, it has the advantage of using SimpleSignal's definition files for strict typing.

    In this case, one can use a generic interface to enforce the correct dispatch/listener parameters:

    // Create, with a given interface as a Generic
    onSomethingHappened = new SimpleSignal<(action:string) => void>();
    
    // The listeners must fulfill the interface
    function myFunc(action:string) {
        console.log(action);
    }
    
    // Subscribe
    onSomethingHappened.add(myFunc);
    
    // Dispatch must also respect the interface
    onSomethingHappened.dispatch("some-action")

    License

    MIT.

    Install

    npm i simplesignal

    DownloadsWeekly Downloads

    2,253

    Version

    5.1.0

    License

    MIT

    Unpacked Size

    67.5 kB

    Total Files

    20

    Last publish

    Collaborators

    • zeh