Return data attribute value from a given element. Falls back to `getAttribute()` in older browsers.

getDataAttributeValue-es2015.js

/**
 * Return data attribute value from a given element. Falls back to `getAttribute()` in older browsers.
 * @example
 * let value = getDataAttributeValue(element, 'component-name');
 * @example
 * let value = getDataAttributeValue(element, 'componentName');
 */
export default function getDataAttributeValue(element, dataName, defaultDataValue = '') {
    const datasetSupported = element.dataset !== undefined;

    if (datasetSupported) {
        let name = dataName.replace(/-([a-z])/g, (name) => return name[1].toUpperCase());
        return element.dataset[name] || defaultDataValue;
    } else {
        let name = "data-" + dataName.replace(/[A-Z]/g, "-$&").toLowerCase();
        return element.getAttribute(name) || defaultDataValue;
    }
};

getDataAttributeValue.js

/**
 * Return data attribute value from a given element. Falls back to `getAttribute()` in older browsers.
 * @example
 * var value = getDataAttributeValue(element, 'component-name');
 * @example
 * var value = getDataAttributeValue(element, 'componentName');
 */
export default function getDataAttributeValue(element, dataName) {
    var datasetSupported = element.dataset !== undefined;

    if (datasetSupported) {
        var name = dataName.replace(/-([a-z])/g, function(name) { return name[1].toUpperCase() });
        return element.dataset[name] || '';
    } else {
        var name = "data-" + dataName.replace(/[A-Z]/g, "-$&").toLowerCase();
        return element.getAttribute(name) || '';
    }
};