source: trunk/fl5/src/com/longtailvideo/jwplayer/utils/Strings.as @ 318

package com.longtailvideo.jwplayer.utils {

        /**
         * This class groups a couple of commonly used string operations.
         * @author Jeroen Wijering
         **/
        public class Strings {

                /**
                 * Unescape a string and filter "asfunction" occurences ( can be used for XSS exploits).
                 *
                 * @param str   The string to decode.
                 * @return              The decoded string.
                 **/
                public static function decode(str:String):String {
                        if (str.indexOf('asfunction') == -1) {
                                return unescape(str);
                        } else {
                                return '';
                        }
                }

                /**
                 * Convert a number to a digital-clock like string.
                 *
                 * @param nbr   The number of seconds.
                 * @return              A MN:SS string.
                 **/
                public static function digits(nbr:Number):String {
                        var min:Number = Math.floor(nbr / 60);
                        var sec:Number = Math.floor(nbr % 60);
                        var str:String = Strings.zero(min) + ':' + Strings.zero(sec);
                        return str;
                }

                /**
                 * Convert a time-representing string to a number.
                 *
                 * @param str   The input string. Supported are 00:03:00.1 / 03:00.1 / 180.1s / 3.2m / 3.2h
                 * @return              The number of seconds.
                 **/
                public static function seconds(str:String):Number {
                        str = str.replace(',', '.');
                        var arr:Array = str.split(':');
                        var sec:Number = 0;
                        if (str.substr(-1) == 's') {
                                sec = Number(str.substr(0, str.length - 1));
                        } else if (str.substr(-1) == 'm') {
                                sec = Number(str.substr(0, str.length - 1)) * 60;
                        } else if (str.substr(-1) == 'h') {
                                sec = Number(str.substr(0, str.length - 1)) * 3600;
                        } else if (arr.length > 1) {
                                sec = Number(arr[arr.length - 1]);
                                sec += Number(arr[arr.length - 2]) * 60;
                                if (arr.length == 3) {
                                        sec += Number(arr[arr.length - 3]) * 3600;
                                }
                        } else {
                                sec = Number(str);
                        }
                        return sec;
                }

                /**
                 * Basic serialization: string representations of booleans and numbers are returned typed;
                 * strings are returned urldecoded.
                 *
                 * @param val   String value to serialize.
                 * @return              The original value in the correct primitive type.
                 **/
                public static function serialize(val:String):Object {
                        if (val == null) {
                                return null;
                        } else if (val == 'true') {
                                return true;
                        } else if (val == 'false') {
                                return false;
                        } else if (isNaN(Number(val)) || val.length > 5) {
                                return val;
                        } else {
                                return Number(val);
                        }
                }

                /**
                 * Strip HTML tags and linebreaks off a string.
                 *
                 * @param str   The string to clean up.
                 * @return              The clean string.
                 **/
                public static function strip(str:String):String {
                        var tmp:Array = str.split("\n");
                        str = tmp.join("");
                        tmp = str.split("\r");
                        str = tmp.join("");
                        var idx:Number = str.indexOf("<");
                        while (idx != -1) {
                                var end:Number = str.indexOf(">", idx + 1);
                                end == -1 ? end = str.length - 1 : null;
                                str = str.substr(0, idx) + " " + str.substr(end + 1, str.length);
                                idx = str.indexOf("<", idx);
                        }
                        return str;
                }

                /**
                 * Add a leading zero to a number.
                 *
                 * @param nbr   The number to convert. Can be 0 to 99.
                 * @ return             A string representation with possible leading 0.
                 **/
                public static function zero(nbr:Number):String {
                        if (nbr < 10) {
                                return '0' + nbr;
                        } else {
                                return '' + nbr;
                        }
                }
                /**
                 * Finds the extension of a filename or URL 
                 * @param filename      The string on which to search
                 * @return                      Everything trailing the final '.' character
                 * 
                 */
                public static function extension(filename:String):String {
                        if (filename.lastIndexOf(".") > 0) {
                                return filename.substring(filename.lastIndexOf(".")+1, filename.length).toLowerCase();
                        } else {
                                return "";
                        }
                }

        }

}