koel/resources/assets/js/services/utils.js

export default {
    /**
     * Convert a duration in seconds into H:i:s format.
     * If H is 0, it will be ommited.
     */
    secondsToHis(d) {
        d = parseInt(d);
        
        var s = d%60;

        if (s < 10) {
            s = '0' + s;
        }

        var i = Math.floor((d/60)%60);

        if (i < 10) {
            i = '0' + i;
        }

        var h = Math.floor(d/3600);

        if (h < 10) {
            h = '0' + h;
        }

        return (h === '00' ? '' : h + ':') + i + ':' + s;
    },

    /**
     * Parse the validation error from the server into a flattened array of messages.
     * 
     * @param  {Object}  error  The error object in JSON format.
     *                                    
     * @return {Array}
     */
    parseValidationError(error) {
        return Object.keys(error).reduce((messages, field) => messages.concat(error[field]), []);
    },

    /**
     * Check if AudioContext is supported by the current browser.
     * 
     * @return {boolean}
     */
    isAudioContextSupported() {
        var AudioContext = window.AudioContext || window.webkitAudioContext || false; 

        if (!AudioContext) {
            return false;
        }

        // Safari (MacOS & iOS alike) has webkitAudioContext, but is buggy.
        // @link http://caniuse.com/#search=audiocontext
        if (!(new AudioContext()).createMediaElementSource) {
            return false;
        }

        return true;
    },
};