utils.js

var utils = exports

/**
 * Returns an indication of whether the argument is an array or not
 */
utils.isArray = function(a) {
    return Object.prototype.toString.call(a) == '[object Array]';
}

/**
 * Returns an indication of whether the argument is a Date or not
 */
utils.isDate = function(d) {
    return Object.prototype.toString.call(d) == '[object Date]';
}

/**
 * Does a deep clone of the object.
 */
utils.clone = function(obj) {
    if(!obj || typeof obj == 'function' || utils.isDate(obj) || typeof obj != 'object') {
        return obj;
    }

    var retVal, i;

    if(utils.isArray(obj)){
        retVal = [];
        for(i = 0; i < obj.length; ++i){
            retVal.push(utils.clone(obj[i]));
        }
        return retVal;
    }

    retVal = {};
    for(i in obj){
        if(!(i in retVal) || retVal[i] != obj[i]) {
            retVal[i] = utils.clone(obj[i]);
        }
    }
    return retVal;
}

/**
 * Returns a wrappered version of the function
 */
utils.close = function(context, func, params) {
    if (typeof params == 'undefined') {
        return function() {
            return func.apply(context, arguments);
        };
    } else {
        return function() {
            return func.apply(context, params);
        };
    }
}

/**
 * Create a UUID
 */
utils.createUUID = function() {
    return UUIDcreatePart(4) + '-' +
        UUIDcreatePart(2) + '-' +
        UUIDcreatePart(2) + '-' +
        UUIDcreatePart(2) + '-' +
        UUIDcreatePart(6);
}

/**
 * Extends a child object from a parent object using classical inheritance
 * pattern.
 */
utils.extend = (function() {
    // proxy used to establish prototype chain
    var F = function() {};
    // extend Child from Parent
    return function(Child, Parent) {
        F.prototype = Parent.prototype;
        Child.prototype = new F();
        Child.__super__ = Parent.prototype;
        Child.prototype.constructor = Child;
    };
}())

/**
 * Alerts a message in any available way: alert or console.log.
 */
utils.alert = function(msg) {
    if (alert) {
        alert(msg);
    } else if (console && console.log) {
        console.log(msg);
    }
}

/**
 * Formats a string and arguments following it ala sprintf()
 *
 * format chars:
 *   %j - format arg as JSON
 *   %o - format arg as JSON
 *   %c - format arg as ''
 *   %% - replace with '%'
 * any other char following % will format it's
 * arg via toString().
 *
 * for rationale, see FireBug's Console API:
 *    http://getfirebug.com/wiki/index.php/Console_API
 */
utils.format = function(formatString /* ,... */) {
    if (formatString == null) return ""
    if (arguments.length == 1) return formatString.toString()

    var pattern = /(.*?)%(.)(.*)/
    var rest    = formatString.toString()
    var result  = []
    var args    = [].slice.call(arguments,1)

    while (args.length) {
        var arg   = args.shift()
        var match = pattern.exec(rest)

        if (!match) break

        rest = match[3]

        result.push(match[1])

        if (match[2] == '%') {
            result.push('%')
            args.unshift(arg)
            continue
        }

        result.push(formatted(arg, match[2]))
    }

    result.push(rest)

    return result.join('')
}

//------------------------------------------------------------------------------
function UUIDcreatePart(length) {
    var uuidpart = "";
    for (var i=0; i<length; i++) {
        var uuidchar = parseInt((Math.random() * 256), 10).toString(16);
        if (uuidchar.length == 1) {
            uuidchar = "0" + uuidchar;
        }
        uuidpart += uuidchar;
    }
    return uuidpart;
}

//------------------------------------------------------------------------------
function formatted(object, formatChar) {

    switch(formatChar) {
        case 'j':
        case 'o': return JSON.stringify(object)
        case 'c': return ''
    }

    if (null == object) return Object.prototype.toString.call(object)

    return object.toString()
}