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    decko
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    1.2.0 • Public • Published

    decko NPM Version Build Status

    A concise implementation of the three most useful decorators:

    • @bind: make the value of this constant within a method
    • @debounce: throttle calls to a method
    • @memoize: cache return values based on arguments

    Decorators help simplify code by replacing the noise of common patterns with declarative annotations. Conversely, decorators can also be overused and create obscurity. Decko establishes 3 standard decorators that are immediately recognizable, so you can avoid creating decorators in your own codebase.

    💡 Tip: decko is particularly well-suited to Preact Classful Components.

    💫 Note:

    Installation

    Available on npm:

    npm i -S decko

    Usage

    Each decorator method is available as a named import.

    import { bind, memoize, debounce } from 'decko';

    @bind

    class Example {
        @bind
        foo() {
            // the value of `this` is always the object from which foo() was referenced.
            return this;
        }
    }
     
    let e = new Example();
    assert.equal(e.foo.call(null), e);

    @memoize

    Cache values returned from the decorated function. Uses the first argument as a cache key. Cache keys are always converted to strings.

    Options:

    caseSensitive: false - Makes cache keys case-insensitive

    cache: {} - Presupply cache storage, for seeding or sharing entries

    class Example {
        @memoize
        expensive(key) {
            let start = Date.now();
            while (Date.now()-start < 500) key++;
            return key;
        }
    }
     
    let e = new Example();
     
    // this takes 500ms
    let one = e.expensive(1);
     
    // this takes 0ms
    let two = e.expensive(1);
     
    // this takes 500ms
    let three = e.expensive(2);

    @debounce

    Throttle calls to the decorated function. To debounce means "call this at most once per N ms". All outward function calls get collated into a single inward call, and only the latest (most recent) arguments as passed on to the debounced function.

    Options:

    delay: 0 - The number of milliseconds to buffer calls for.

    class Example {
        @debounce
        foo() {
            return this;
        }
    }
     
    let e = new Example();
     
    // this will only call foo() once:
    for (let i=1000; i--) e.foo();

    License

    MIT

    Keywords

    none

    Install

    npm i decko

    DownloadsWeekly Downloads

    208,440

    Version

    1.2.0

    License

    none

    Last publish

    Collaborators

    • developit