Counter

Counter is a JavaScript class for animating a numeric counter that starts when scrolled into view. It uses GSAP and ScrollTrigger to animate a number from an initial to a final value with customizable options.

Usage Example

import Counter from "@terrahq/counter";

const counter = new Counter({
    element: document.querySelector(".counter-element"),
    endValue: 5000, // The final value of the counter
    duration: 2, // Duration of the animation in seconds
    separator: ".", // Thousands separator (optional)
    start: "top center", // ScrollTrigger start position (optional)
    debug: true, // Display ScrollTrigger markers (optional, now called debug)
    easing: "power1.out", // Easing of the animation (optional)
    autoPlay: true, // Start animation on scroll (optional)
    playOnce: true, // Run animation only once (optional)
    decimalPlaces: 0, // Where the '.' will be located when it is a decimal number (optional)
    onComplete: () => console.log("Counter animation complete!"), // Callback on animation complete
});

// Additional methods
counter.play(); // Start the animation manually
counter.update(); // Update the ScrollTrigger position
counter.destroy(); // Clean up the instance and stop animations

Constructor Parameters

• element (HTMLElement, required): The HTML element that will display the animated number.
• endValue (Number, optional): The end value for the counter animation. Default is 1000.
• duration (Number, optional): Duration of the animation in seconds. Default is 2.
• separator (String, optional): Thousands separator in the number animation. Default is ",".
• start (String, optional): ScrollTrigger start position. Default is "top top".
• debug (Boolean, optional): Show ScrollTrigger markers for debugging. Default is false.
• easing (String, optional): Type of GSAP easing for the animation. Default is "power1.out".
• autoPlay (Boolean, optional): If true, the animation starts on reaching the start ScrollTrigger point. Default is false.
• playOnce (Boolean, optional): If true, the animation runs only once. Default is false.
• decimalPlaces (Number, optional): Where the '.' will be located when it is a decimal number.
• onComplete (Function, optional): Callback function executed when the counter animation completes.

Methods

• play(): Manually starts the counter animation.
• destroy(): Cleans up ScrollTrigger and stops the animation, freeing resources.
• update(): Updates the ScrollTrigger position by recalculating its starting point.

Examples

html

<div class="counter counter-element">1</div>

Javascript

const counter = new Counter({
    element: document.querySelector(".counter-element"),
    endValue: 5000, // The final value of the counter
    duration: 2, // Duration of the animation in seconds
    separator: ".", // Thousands separator (optional)
    start: "top center", // ScrollTrigger start position (optional)
    debug: true, // Display ScrollTrigger markers (optional, now called debug)
    easing: "power1.out", // Easing of the animation (optional)
    autoPlay: true, // Start animation on scroll (optional)
    playOnce: true, // Run animation only once (optional)
    decimalPlaces: 0, // Where the '.' will be located when it is a decimal number (optional)
    onComplete: () => console.log("Counter animation complete!"), // Callback on animation complete
});