/util.php

<?php
/**
 * util.php
 *
 * util.php is a library of helper functions for common tasks such as
 * formatting bytes as a string or displaying a date in terms of how long ago
 * it was in human readable terms (E.g. 4 minutes ago). The library is entirely
 * contained within a single file and hosts no dependencies. The library is
 * designed to avoid any possible conflicts.
 *
 * @author   Brandon Wamboldt
 * @link     http://github.com/brandonwamboldt/utilphp/ Official Documentation
 * @version  1.0.004
 */

if ( ! class_exists( 'util' ) ) {
    class util
    {
        /**
         * A constant representing the number of seconds in a minute, for
         * making code more verbose
         *
         * @since  1.0.000
         * @var    int
         */
        const SECONDS_IN_A_MINUTE = 60;

        /**
         * A constant representing the number of seconds in an hour, for making
         * code more verbose
         *
         * @since  1.0.000
         * @var    int
         */
        const SECONDS_IN_A_HOUR   = 3600;
        const SECONDS_IN_AN_HOUR  = 3600;

        /**
         * A constant representing the number of seconds in a day, for making
         * code more verbose
         *
         * @since  1.0.000
         * @var    int
         */
        const SECONDS_IN_A_DAY    = 86400;

        /**
         * A constant representing the number of seconds in a week, for making
         * code more verbose
         *
         * @since  1.0.000
         * @var    int
         */
        const SECONDS_IN_A_WEEK   = 604800;

        /**
         * A constant representing the number of seconds in a month (30 days),
         * for making code more verbose
         *
         * @since  1.0.000
         * @var    int
         */
        const SECONDS_IN_A_MONTH  = 2592000;

        /**
         * A constant representing the number of seconds in a year (365 days),
         * for making code more verbose
         *
         * @since  1.0.000
         * @var    int
         */
        const SECONDS_IN_A_YEAR   = 31536000;

        /**
         * A collapse icon, using in the dump_var function to allow collapsing
         * an array or object
         *
         * @access  public
         * @since   1.0.000
         * @static
         * @var     string
         */
        public static $icon_collapse = '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';

        /**
         * A collapse icon, using in the dump_var function to allow collapsing
         * an array or object
         *
         * @access  public
         * @since   1.0.000
         * @static
         * @var     string
         */
        public static $icon_expand = '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';

        /**
         * Access an array index, retrieving the value stored there if it
         * exists or a default if it does not. This function allows you to
         * concisely access an index which may or may not exist without
         * raising a warning
         *
         * @param   array   $var      Array to access
         * @param   string  $field    Index to access in the array
         * @param   mixed   $default  Default value to return if the key is not
         *                            present in the array
         * @return  mixed
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_get( & $var, $default = NULL )
        {
            if ( isset( $var ) ) {
                return $var;
            } else {
                return $default;
            }
        }

        /**
         * Display a variable's contents using nice HTML formatting and will
         * properly display the value of booleans as true or false
         *
         * @param   mixed  $var  The variable to dump
         * @return  string
         *
         * @see     var_dump_plain()
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function var_dump( $var, $return = FALSE )
        {
            $html = '<pre style="margin-bottom: 18px;' .
                'background: #f7f7f9;' .
                'border: 1px solid #e1e1e8;' .
                'padding: 8px;' .
                'border-radius: 4px;' .
                '-moz-border-radius: 4px;' .
                '-webkit-border radius: 4px;' .
                'display: block;' .
                'font-size: 12.05px;' .
                'white-space: pre-wrap;' .
                'word-wrap: break-word;' .
                'color: #333;' .
                'font-family: Menlo,Monaco,Consolas,\'Courier New\',monospace;">';
            $html .= self::var_dump_plain( $var );
            $html .= '</pre>';

            if ( ! $return ) {
                echo $html;
            } else {
                return $html;
            }
        }

        /**
         * Display a variable's contents using nice HTML formatting (Without
         * the <pre> tag) and will properly display the values of variables
         * like booleans and resources. Supports collapsable arrays and objects
         * as well.
         *
         * @param   mixed  $var  The variable to dump
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function var_dump_plain( $var )
        {
            $html = '';

            if ( is_bool( $var ) ) {
                $html .= '<span style="color:#588bff;">bool</span><span style="color:#999;">(</span><strong>' . ( ( $var ) ? 'true' : 'false' ) . '</strong><span style="color:#999;">)</span>';
            } else if ( is_int( $var ) ) {
                $html .= '<span style="color:#588bff;">int</span><span style="color:#999;">(</span><strong>' . $var . '</strong><span style="color:#999;">)</span>';
            } else if ( is_float( $var ) ) {
                $html .= '<span style="color:#588bff;">float</span><span style="color:#999;">(</span><strong>' . $var . '</strong><span style="color:#999;">)</span>';
            } else if ( is_string( $var ) ) {
                $html .= '<span style="color:#588bff;">string</span><span style="color:#999;">(</span>' . strlen( $var ) . '<span style="color:#999;">)</span> <strong>"' . self::htmlentities( $var ) . '"</strong>';
            } else if ( is_null( $var ) ) {
                $html .= '<strong>NULL</strong>';
            } else if ( is_resource( $var ) ) {
                $html .= '<span style="color:#588bff;">resource</span>("' . get_resource_type( $var ) . '") <strong>"' . $var . '"</strong>';
            } else if ( is_array( $var ) ) {
                $uuid = 'include-php-' . uniqid();

                $html .= '<span style="color:#588bff;">array</span>(' . count( $var ) . ')';

                if ( ! empty( $var ) ) {
                    $html .= ' <img id="' . $uuid . '" data-expand="data:image/png;base64,' . self::$icon_expand . '" style="position:relative;left:-5px;top:-1px;cursor:pointer;" src="data:image/png;base64,' . self::$icon_collapse . '" /><br /><span id="' . $uuid . '-collapsable">[<br />';

                    $indent = 4;
                    $longest_key = 0;

                    foreach( $var as $key => $value ) {
                        if ( is_string( $key ) ) {
                            $longest_key = max( $longest_key, strlen( $key ) + 2 );
                        } else {
                            $longest_key = max( $longest_key, strlen( $key ) );
                        }
                    }

                    foreach ( $var as $key => $value ) {
                        if ( is_numeric( $key ) ) {
                            $html .= str_repeat( ' ', $indent ) . str_pad( $key, $longest_key, ' ');
                        } else {
                            $html .= str_repeat( ' ', $indent ) . str_pad( '"' . self::htmlentities( $key ) . '"', $longest_key, ' ' );
                        }

                        $html .= ' => ';

                        $value = explode( '<br />', self::var_dump_plain( $value ) );

                        foreach ( $value as $line => $val ) {
                            if ( $line != 0 ) {
                                $value[$line] = str_repeat( ' ', $indent * 2 ) . $val;
                            }
                        }

                        $html .= implode( '<br />', $value ) . '<br />';
                    }

                    $html .= ']</span>';

                    $html .= preg_replace( '/ +/', ' ', '<script type="text/javascript">(function() {
                    var img = document.getElementById("' . $uuid . '");
                    img.onclick = function() {
                        if ( document.getElementById("' . $uuid . '-collapsable").style.display == "none" ) {
                            document.getElementById("' . $uuid . '-collapsable").style.display = "inline";
                            img.src = img.getAttribute("data-collapse");
                            var previousSibling = document.getElementById("' . $uuid . '-collapsable").previousSibling;

                            while ( previousSibling != null && ( previousSibling.nodeType != 1 || previousSibling.tagName.toLowerCase() != "br" ) ) {
                                previousSibling = previousSibling.previousSibling;
                            }

                            if ( previousSibling != null && previousSibling.tagName.toLowerCase() == "br" ) {
                                previousSibling.style.display = "inline";
                            }
                        } else {
                            document.getElementById("' . $uuid . '-collapsable").style.display = "none";
                            img.setAttribute( "data-collapse", img.getAttribute("src") );
                            img.src = img.getAttribute("data-expand");
                            var previousSibling = document.getElementById("' . $uuid . '-collapsable").previousSibling;

                            while ( previousSibling != null && ( previousSibling.nodeType != 1 || previousSibling.tagName.toLowerCase() != "br" ) ) {
                                previousSibling = previousSibling.previousSibling;
                            }

                            if ( previousSibling != null && previousSibling.tagName.toLowerCase() == "br" ) {
                                previousSibling.style.display = "none";
                            }
                        }
                    };
                    })();
                    </script>' );
                }
            } else if ( is_object( $var ) ) {
                $uuid = 'include-php-' . uniqid();

                $html .= '<span style="color:#588bff;">object</span>(' . get_class( $var ) . ') <img id="' . $uuid . '" data-expand="data:image/png;base64,' . self::$icon_expand . '" style="position:relative;left:-5px;top:-1px;cursor:pointer;" src="data:image/png;base64,' . self::$icon_collapse . '" /><br /><span id="' . $uuid . '-collapsable">[<br />';

                $original = $var;
                $var = (array) $var;

                $indent = 4;
                $longest_key = 0;

                foreach( $var as $key => $value ) {
                    if ( substr( $key, 0, 2 ) == "\0*" ) {
                        unset( $var[$key] );
                        $key = 'protected:' . substr( $key, 2 );
                        $var[$key] = $value;
                    } else if ( substr( $key, 0, 1 ) == "\0" ) {
                        unset( $var[$key] );
                        $key = 'private:' . substr( $key, 1, strpos( substr( $key, 1 ), "\0" ) ) . ':' . substr( $key, strpos( substr( $key, 1 ), "\0" ) + 1 );
                        $var[$key] = $value;
                    }

                    if ( is_string( $key ) ) {
                        $longest_key = max( $longest_key, strlen( $key ) + 2 );
                    } else {
                        $longest_key = max( $longest_key, strlen( $key ) );
                    }
                }

                foreach ( $var as $key => $value ) {
                    if ( is_numeric( $key ) ) {
                        $html .= str_repeat( ' ', $indent ) . str_pad( $key, $longest_key, ' ');
                    } else {
                        $html .= str_repeat( ' ', $indent ) . str_pad( '"' . self::htmlentities( $key ) . '"', $longest_key, ' ' );
                    }

                    $html .= ' => ';

                    $value = explode( '<br />', self::var_dump_plain( $value ) );

                    foreach ( $value as $line => $val ) {
                        if ( $line != 0 ) {
                            $value[$line] = str_repeat( ' ', $indent * 2 ) . $val;
                        }
                    }

                    $html .= implode( '<br />', $value ) . '<br />';
                }

                $html .= ']</span>';

                $html .= preg_replace( '/ +/', ' ', '<script type="text/javascript">(function() {
                var img = document.getElementById("' . $uuid . '");
                img.onclick = function() {
                    if ( document.getElementById("' . $uuid . '-collapsable").style.display == "none" ) {
                        document.getElementById("' . $uuid . '-collapsable").style.display = "inline";
                        img.src = img.getAttribute("data-collapse");
                        var previousSibling = document.getElementById("' . $uuid . '-collapsable").previousSibling;

                        while ( previousSibling != null && ( previousSibling.nodeType != 1 || previousSibling.tagName.toLowerCase() != "br" ) ) {
                            previousSibling = previousSibling.previousSibling;
                        }

                        if ( previousSibling != null && previousSibling.tagName.toLowerCase() == "br" ) {
                            previousSibling.style.display = "inline";
                        }
                    } else {
                        document.getElementById("' . $uuid . '-collapsable").style.display = "none";
                        img.setAttribute( "data-collapse", img.getAttribute("src") );
                        img.src = img.getAttribute("data-expand");
                        var previousSibling = document.getElementById("' . $uuid . '-collapsable").previousSibling;

                        while ( previousSibling != null && ( previousSibling.nodeType != 1 || previousSibling.tagName.toLowerCase() != "br" ) ) {
                            previousSibling = previousSibling.previousSibling;
                        }

                        if ( previousSibling != null && previousSibling.tagName.toLowerCase() == "br" ) {
                            previousSibling.style.display = "none";
                        }
                    }
                };
                })();
                </script>' );
            }

            return $html;
        }

        /**
         * Converts any accent characters to their equivalent normal characters
         * and converts any other non-alphanumeric characters to dashes, then
         * converts any sequence of two or more dashes to a single dash. This
         * function generates slugs safe for use as URLs, and if you pass TRUE
         * as the second parameter, it will create strings safe for use as CSS
         * classes or IDs
         *
         * @param   string  $string    A string to convert to a slug
         * @param   bool    $css_mode  Whether or not to generate strings safe
         *                             for CSS classes/IDs (Default to false)
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function slugify( $string, $css_mode = FALSE )
        {
            $slug = preg_replace( '/([^a-z0-9]+)/', '-', strtolower( self::remove_accents( $string ) ) );

            if ( $css_mode ) {
                $digits = array( 'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine' );

                if ( is_numeric( substr( $slug, 0, 1 ) ) ) {
                    $slug = $digits[substr( $slug, 0, 1 )] . substr( $slug, 1 );
                }
            }

            return $slug;
        }

        /**
         * Checks to see if a string is utf8 encoded.
         *
         * NOTE: This function checks for 5-Byte sequences, UTF8
         *       has Bytes Sequences with a maximum length of 4.
         *
         * @param   string  $string  The string to be checked
         * @return  bool
         *
         * @link    https://github.com/facebook/libphutil/blob/master/src/utils/utf8.php
         *
         * @access  public
         * @author  bmorel@ssi.fr
         * @since   1.0.000
         * @static
         */
        public static function seems_utf8( $string )
        {
            if ( function_exists( 'mb_check_encoding' ) ) {
                // If mbstring is available, this is significantly faster than
                // using PHP regexps.
                return mb_check_encoding( $string, 'UTF-8' );
            }

            $regex = '/(
    | [\xF8-\xFF] # Invalid UTF-8 Bytes
    | [\xC0-\xDF](?![\x80-\xBF]) # Invalid UTF-8 Sequence Start
    | [\xE0-\xEF](?![\x80-\xBF]{2}) # Invalid UTF-8 Sequence Start
    | [\xF0-\xF7](?![\x80-\xBF]{3}) # Invalid UTF-8 Sequence Start
    | (?<=[\x0-\x7F\xF8-\xFF])[\x80-\xBF] # Invalid UTF-8 Sequence Middle
    | (?<![\xC0-\xDF]|[\xE0-\xEF]|[\xE0-\xEF][\x80-\xBF]|[\xF0-\xF7]|[\xF0-\xF7][\x80-\xBF]|[\xF0-\xF7][\x80-\xBF]{2})[\x80-\xBF] # Overlong Sequence
    | (?<=[\xE0-\xEF])[\x80-\xBF](?![\x80-\xBF]) # Short 3 byte sequence
    | (?<=[\xF0-\xF7])[\x80-\xBF](?![\x80-\xBF]{2}) # Short 4 byte sequence
    | (?<=[\xF0-\xF7][\x80-\xBF])[\x80-\xBF](?![\x80-\xBF]) # Short 4 byte sequence (2)
)/x';

            return ! preg_match( $regex, $string );
        }

        /**
         * Nice formatting for computer sizes (Bytes)
         *
         * @param   int  $bytes     The number in bytes to format
         * @param   int  $decimals  The number of decimal points to include
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function size_format( $bytes, $decimals = 0 )
        {
            $bytes = floatval( $bytes );

            if ( $bytes < 1024 ) {
                return $bytes . ' B';
            } else if ( $bytes < pow( 1024, 2 ) ) {
                return number_format( $bytes / 1024, $decimals, '.', '' ) . ' KiB';
            } else if ( $bytes < pow( 1024, 3 ) ) {
                return number_format( $bytes / pow( 1024, 2 ), $decimals, '.', '' ) . ' MiB';
            } else if ( $bytes < pow( 1024, 4 ) ) {
                return number_format( $bytes / pow( 1024, 3 ), $decimals, '.', '' ) . ' GiB';
            } else if ( $bytes < pow( 1024, 5 ) ) {
                return number_format( $bytes / pow( 1024, 4 ), $decimals, '.', '' ) . ' TiB';
            } else if ( $bytes < pow( 1024, 6 ) ) {
                return number_format( $bytes / pow( 1024, 5 ), $decimals, '.', '' ) . ' PiB';
            } else {
                return number_format( $bytes / pow( 1024, 5 ), $decimals, '.', '' ) . ' PiB';
            }
        }

        /**
         * Serialize data, if needed.
         *
         * @param   mixed  $data  Data that might need to be serialized
         * @return  mixed
         *
         * @link    http://codex.wordpress.org/Function_Reference/maybe_serialize
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function maybe_serialize( $data )
        {
            if ( is_array( $data ) || is_object( $data ) ) {
                return serialize( $data );
            }

            return $data;
        }

        /**
         * Unserialize value only if it is serialized
         *
         * @param   string $data A variable that may or may not be serialized
         * @return  mixed
         *
         * @link    http://codex.wordpress.org/Function_Reference/maybe_unserialize
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function maybe_unserialize( $data )
        {
             // Don't attempt to unserialize data that isn't serialized
            if ( self::is_serialized( $data ) ) {
                return @unserialize( $data );
            }

            return $data;
        }

        /**
         * Check value to find if it was serialized.
         *
         * If $data is not an string, then returned value will always be false.
         * Serialized data is always a string.
         *
         * @param   mixed  $data  Value to check to see if was serialized
         * @return  bool
         *
         * @link    http://codex.wordpress.org/Function_Reference/is_serialized
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function is_serialized( $data )
        {
            // If it isn't a string, it isn't serialized
            if ( ! is_string( $data ) ) {
                return FALSE;
            }

            $data = trim( $data );

            if ( 'N;' == $data ) {
                return TRUE;
            }

            $length = strlen( $data );

            if ( $length < 4 ) {
                return FALSE;
            }

            if ( ':' !== $data[1] ) {
                return FALSE;
            }

            $lastc = $data[$length - 1];

            if ( ';' !== $lastc && '}' !== $lastc ) {
                return FALSE;
            }

            $token = $data[0];

            switch ( $token ) {
                case 's' :
                    if ( '"' !== $data[$length-2] ) {
                        return FALSE;
                    }
                case 'a' :
                case 'O' :
                    return (bool) preg_match( "/^{$token}:[0-9]+:/s", $data );
                case 'b' :
                case 'i' :
                case 'd' :
                    return (bool) preg_match( "/^{$token}:[0-9.E-]+;\$/", $data );
            }

            return FALSE;
        }

        /**
         * Checks to see if the page is being server over SSL or not
         *
         * @return  bool
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function is_https()
        {
            if ( isset( $_SERVER['HTTPS'] ) && ! empty( $_SERVER['HTTPS'] ) && $_SERVER['HTTPS'] != 'off' ) {
                return TRUE;
            } else {
                return FALSE;
            }
        }

        /**
         * Retrieve a modified URL query string.
         *
         * You can rebuild the URL and append a new query variable to the URL
         * query by using this function. You can also retrieve the full URL
         * with query data.
         *
         * Adding a single key & value or an associative array. Setting a key
         * value to an empty string removes the key. Omitting oldquery_or_uri
         * uses the $_SERVER value. Additional values provided are expected
         * to be encoded appropriately with urlencode() or rawurlencode().
         *
         * @param   mixed  $newkey          Either newkey or an associative
         *                                  array
         * @param   mixed  $newvalue        Either newvalue or oldquery or uri
         * @param   mixed  $oldquery_or_uri Optionally the old query or uri
         * @return  string
         *
         * @link    http://codex.wordpress.org/Function_Reference/add_query_arg
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function add_query_arg()
        {
            $ret = '';

            // Was an associative array of key => value pairs passed?
            if ( is_array( func_get_arg( 0 ) ) ) {

                // Was the URL passed as an argument?
                if ( func_num_args() == 2 && func_get_arg( 1 ) ) {
                    $uri = func_get_arg( 1 );
                } else if ( func_num_args() == 3 && func_get_arg( 2 ) ) {
                    $uri = func_get_arg( 2 );
                } else {
                    $uri = $_SERVER['REQUEST_URI'];
                }
            } else {

                // Was the URL passed as an argument?
                if ( func_num_args() == 3 && func_get_arg( 2 ) ) {
                    $uri = func_get_arg( 2 );
                } else {
                    $uri = $_SERVER['REQUEST_URI'];
                }
            }

            // Does the URI contain a fragment section (The part after the #)
            if ( $frag = strstr( $uri, '#' ) ) {
                $uri = substr( $uri, 0, -strlen( $frag ) );
            } else {
                $frag = '';
            }

            // Get the URI protocol if possible
            if ( preg_match( '|^https?://|i', $uri, $matches ) ) {
                $protocol = $matches[0];
                $uri = substr( $uri, strlen( $protocol ) );
            } else {
                $protocol = '';
            }

            // Does the URI contain a query string?
            if ( strpos( $uri, '?' ) !== FALSE ) {
                $parts = explode( '?', $uri, 2 );

                if ( 1 == count( $parts ) ) {
                    $base  = '?';
                    $query = $parts[0];
                } else {
                    $base  = $parts[0] . '?';
                    $query = $parts[1];
                }
            } else if ( ! empty( $protocol ) || strpos( $uri, '=' ) === FALSE ) {
                $base  = $uri . '?';
                $query = '';
            } else {
                $base  = '';
                $query = $uri;
            }

            // Parse the query string into an array
            parse_str( $query, $qs );

            // This re-URL-encodes things that were already in the query string
            $qs = self::array_map_deep( $qs, 'urlencode' );

            if ( is_array( func_get_arg( 0 ) ) ) {
                $kayvees = func_get_arg( 0 );
                $qs = array_merge( $qs, $kayvees );
            } else {
                $qs[func_get_arg( 0 )] = func_get_arg( 1 );
            }

            foreach ( (array) $qs as $k => $v ) {
                if ( $v === false )
                    unset( $qs[$k] );
            }

            $ret = http_build_query( $qs );
            $ret = trim( $ret, '?' );
            $ret = preg_replace( '#=(&|$)#', '$1', $ret );
            $ret = $protocol . $base . $ret . $frag;
            $ret = rtrim( $ret, '?' );
            return $ret;
        }

        /**
         * Removes an item or list from the query string.
         *
         * @param   string|array  $keys  Query key or keys to remove.
         * @param   bool          $uri   When false uses the $_SERVER value
         * @return  string
         *
         * @link    http://codex.wordpress.org/Function_Reference/remove_query_arg
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function remove_query_arg( $keys, $uri = FALSE )
        {
            if ( is_array( $keys ) ) {
                foreach ( $keys as $key ) {
                    $uri = self::add_query_arg( $key, FALSE, $uri );
                }

                return $uri;
            }

            return self::add_query_arg( $keys, FALSE, $uri );
        }

        /**
         * Converts many english words that equate to true or false to boolean
         *
         * Supports 'y', 'n', 'yes', 'no' and a few other variations
         *
         * @param   string  $string   The string to convert to boolean
         * @param   bool    $default  The value to return if we can't match any
         *                            yes/no words
         * @return  bool
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function str_to_bool( $string, $default = FALSE )
        {
            $yes_words = 'affirmative|all right|aye|indubitably|most assuredly|ok|of course|okay|sure thing|y|yes+|yea|yep|sure|yeah|true|t|on|1';
            $no_words = 'no*|no way|nope|nah|na|never|absolutely not|by no means|negative|never ever|false|f|off|0';

            if ( preg_match( '/^(' . $yes_words . ')$/i', $string ) ) {
                return TRUE;
            } else if ( preg_match( '/^(' . $no_words . ')$/i', $string ) ) {
                return FALSE;
            } else {
                return $default;
            }
        }

        /**
         * Convert entities, while preserving already-encoded entities
         *
         * @param   string  $string  The text to be converted
         * @return  string
         *
         * @link    http://ca2.php.net/manual/en/function.htmlentities.php#90111
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function htmlentities( $string, $preserve_encoded_entities = FALSE )
        {
            if ( $preserve_encoded_entities ) {
                $translation_table = get_html_translation_table( HTML_ENTITIES, ENT_QUOTES, mb_internal_encoding() );
                $translation_table[chr(38)] = '&';
                return preg_replace( '/&(?![A-Za-z]{0,4}\w{2,3};|#[0-9]{2,3};)/', '&amp;', strtr( $string, $translation_table ) );
            } else {
                return htmlentities( $string, ENT_QUOTES, mb_internal_encoding() );
            }
        }

        /**
         * Convert >, <, ', " and & to html entities, but preserves entities
         * that are already encoded
         *
         * @param   string  $string  The text to be converted
         * @return  string
         *
         * @link    http://ca2.php.net/manual/en/function.htmlentities.php#90111
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function htmlspecialchars( $string, $preserve_encoded_entities = FALSE  )
        {
            if ( $preserve_encoded_entities ) {
                $translation_table            = get_html_translation_table( HTML_SPECIALCHARS, ENT_QUOTES, mb_internal_encoding() );
                $translation_table[chr( 38 )] = '&';

                return preg_replace( '/&(?![A-Za-z]{0,4}\w{2,3};|#[0-9]{2,3};)/', '&amp;', strtr( $string, $translation_table ) );
            } else {
                return htmlentities( $string, ENT_QUOTES, mb_internal_encoding() );
            }
        }

        /**
         * Converts all accent characters to ASCII characters
         *
         * If there are no accent characters, then the string given is just
         * returned
         *
         * @param   string  $string  Text that might have accent characters
         * @return  string  Filtered string with replaced "nice" characters
         *
         * @link    http://codex.wordpress.org/Function_Reference/remove_accents
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function remove_accents( $string )
        {
            if ( ! preg_match( '/[\x80-\xff]/', $string ) ) {
                return $string;
            }

            if ( self::seems_utf8( $string ) ) {
                $chars = array(

                    // Decompositions for Latin-1 Supplement
                    chr(194).chr(170) => 'a', chr(194).chr(186) => 'o',
                    chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
                    chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
                    chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
                    chr(195).chr(134) => 'AE',chr(195).chr(135) => 'C',
                    chr(195).chr(136) => 'E', chr(195).chr(137) => 'E',
                    chr(195).chr(138) => 'E', chr(195).chr(139) => 'E',
                    chr(195).chr(140) => 'I', chr(195).chr(141) => 'I',
                    chr(195).chr(142) => 'I', chr(195).chr(143) => 'I',
                    chr(195).chr(144) => 'D', chr(195).chr(145) => 'N',
                    chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
                    chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
                    chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
                    chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
                    chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
                    chr(195).chr(158) => 'TH',chr(195).chr(159) => 's',
                    chr(195).chr(160) => 'a', chr(195).chr(161) => 'a',
                    chr(195).chr(162) => 'a', chr(195).chr(163) => 'a',
                    chr(195).chr(164) => 'a', chr(195).chr(165) => 'a',
                    chr(195).chr(166) => 'ae',chr(195).chr(167) => 'c',
                    chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
                    chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
                    chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
                    chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
                    chr(195).chr(176) => 'd', chr(195).chr(177) => 'n',
                    chr(195).chr(178) => 'o', chr(195).chr(179) => 'o',
                    chr(195).chr(180) => 'o', chr(195).chr(181) => 'o',
                    chr(195).chr(182) => 'o', chr(195).chr(184) => 'o',
                    chr(195).chr(185) => 'u', chr(195).chr(186) => 'u',
                    chr(195).chr(187) => 'u', chr(195).chr(188) => 'u',
                    chr(195).chr(189) => 'y', chr(195).chr(190) => 'th',
                    chr(195).chr(191) => 'y', chr(195).chr(152) => 'O',

                    // Decompositions for Latin Extended-A
                    chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
                    chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
                    chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
                    chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
                    chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
                    chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
                    chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
                    chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
                    chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
                    chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
                    chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
                    chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
                    chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
                    chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
                    chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
                    chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
                    chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
                    chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
                    chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
                    chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
                    chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
                    chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
                    chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
                    chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
                    chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
                    chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
                    chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
                    chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
                    chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
                    chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
                    chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
                    chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
                    chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
                    chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
                    chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
                    chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
                    chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
                    chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
                    chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
                    chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
                    chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
                    chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
                    chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
                    chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
                    chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
                    chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
                    chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
                    chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
                    chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
                    chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
                    chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
                    chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
                    chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
                    chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
                    chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
                    chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
                    chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
                    chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
                    chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
                    chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
                    chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
                    chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
                    chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
                    chr(197).chr(190) => 'z', chr(197).chr(191) => 's',

                    // Decompositions for Latin Extended-B
                    chr(200).chr(152) => 'S', chr(200).chr(153) => 's',
                    chr(200).chr(154) => 'T', chr(200).chr(155) => 't',

                    // Euro Sign
                    chr(226).chr(130).chr(172) => 'E',
                    // GBP (Pound) Sign
                    chr(194).chr(163) => ''
                );

                $string = strtr( $string, $chars );
            } else {

                // Assume ISO-8859-1 if not UTF-8
                $chars['in'] = chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
                     .chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
                     .chr(195).chr(196).chr(197).chr(199).chr(200).chr(201).chr(202)
                     .chr(203).chr(204).chr(205).chr(206).chr(207).chr(209).chr(210)
                     .chr(211).chr(212).chr(213).chr(214).chr(216).chr(217).chr(218)
                     .chr(219).chr(220).chr(221).chr(224).chr(225).chr(226).chr(227)
                     .chr(228).chr(229).chr(231).chr(232).chr(233).chr(234).chr(235)
                     .chr(236).chr(237).chr(238).chr(239).chr(241).chr(242).chr(243)
                     .chr(244).chr(245).chr(246).chr(248).chr(249).chr(250).chr(251)
                     .chr(252).chr(253).chr(255);

                $chars['out'] = 'EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy';

                $string = strtr( $string, $chars['in'], $chars['out'] );
                $double_chars['in'] = array( chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254) );
                $double_chars['out'] = array( 'OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th' );
                $string = str_replace( $double_chars['in'], $double_chars['out'], $string );
            }

            return $string;
        }

        /**
         * Pads a given string with zeroes on the left
         *
         * @param   int  $number  The number to pad
         * @param   int  $length  The total length of the desired string
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function zero_pad( $number, $length )
        {
            return str_pad( $number, $length, '0', STR_PAD_LEFT );
        }

        /**
         * Converts a unix timestamp to a relative time string, such as "3 days
         * ago" or "2 weeks ago"
         *
         * @param   int     $from    The date to use as a starting point
         * @param   int     $to      The date to compare to. Defaults to the
         *                           current time
         * @param   string  $suffix  The string to add to the end, defaults to
         *                           " ago"
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function human_time_diff( $from, $to = '', $as_text = FALSE, $suffix = ' ago' )
        {
            if ( $to == '' ) {
                $to = time();
            }

            $from = new DateTime( date( 'Y-m-d H:i:s', $from ) );
            $to   = new DateTime( date( 'Y-m-d H:i:s', $to ) );
            $diff = $from->diff( $to );

            if ( $diff->y > 1 ) {
                $text = $diff->y . ' years';
            } else if ( $diff->y == 1 ) {
                $text = '1 year';
            } else if ( $diff->m > 1 ) {
                $text = $diff->m . ' months';
            } else if ( $diff->m == 1 ) {
                $text = '1 month';
            } else if ( $diff->d > 7 ) {
                $text = ceil( $diff->d / 7 ) . ' weeks';
            } else if ( $diff->d == 7 ) {
                $text = '1 week';
            } else if ( $diff->d > 1 ) {
                $text = $diff->d . ' days';
            } else if ( $diff->d == 1 ) {
                $text = '1 day';
            } else if ( $diff->h > 1 ) {
                $text = $diff->h . ' hours';
            } else if ( $diff->h == 1 ) {
                $text = ' 1 hour';
            } else if ( $diff->i > 1 ) {
                $text = $diff->i . ' minutes';
            } else if ( $diff->i == 1 ) {
                $text = '1 minute';
            } else if ( $diff->s > 1 ) {
                $text = $diff->s . ' seconds';
            } else {
                $text = '1 second';
            }

            if ( $as_text ) {
                $text = explode( ' ', $text, 2 );
                $text = self::number_to_word( $text[0] ) . ' ' . $text[1];
            }

            return trim( $text ) . $suffix;
        }

        /**
         * Converts a number into the text equivalent. For example, 456 becomes
         * four hundred and fifty-six
         *
         * @param   int|float  $number  The number to convert into text
         * @return  string
         *
         * @link    http://bloople.net/num2text
         *
         * @access  public
         * @author  Brenton Fletcher
         * @since   1.0.000
         * @static
         */
        public static function number_to_word( $number )
        {
            $number = (string) $number;

            if ( strpos( $number, '.' ) !== FALSE ) {
                list( $number, $decimal ) = explode( '.', $number );
            } else {
                $number = $number;
                $decimal = FALSE;
            }

            $output = '';

            if ( $number[0] == '-' ) {
                $output = 'negative ';
                $number = ltrim( $number, '-' );
            } else if ( $number[0] == '+' ) {
                $output = 'positive ';
                $number = ltrim( $number, '+' );
            }

            if ( $number[0] == '0' ) {
                $output .= 'zero';
            } else {
                $number = str_pad( $number, 36, '0', STR_PAD_LEFT );
                $group  = rtrim( chunk_split( $number, 3, ' ' ), ' ' );
                $groups = explode( ' ', $group );

                $groups2 = array();

                foreach ( $groups as $group ) {
                    $groups2[] = self::_number_to_word_three_digits( $group[0], $group[1], $group[2] );
                }

                for ( $z = 0; $z < count( $groups2 ); $z++ ) {
                    if ( $groups2[$z] != '' ) {
                        $output .= $groups2[$z] . self::_number_to_word_convert_group( 11 - $z );
                        $output .= ( $z < 11 && ! array_search( '', array_slice( $groups2, $z + 1, -1 ) ) && $groups2[11] != '' && $groups[11][0] == '0' ? ' and ' : ', ' );
                    }
                }

                $output = rtrim( $output, ', ' );
            }

            if ( $decimal > 0 ) {
                $output .= ' point';

                for ( $i = 0; $i < strlen( $decimal ); $i++ ) {
                    $output .= ' ' . self::_number_to_word_convert_digit( $decimal[$i] );
                }
            }

            return $output;
        }

        protected static function _number_to_word_convert_group( $index )
        {
            switch( $index ) {
                case 11:
                    return ' decillion';
                case 10:
                    return ' nonillion';
                case 9:
                    return ' octillion';
                case 8:
                    return ' septillion';
                case 7:
                    return ' sextillion';
                case 6:
                    return ' quintrillion';
                case 5:
                    return ' quadrillion';
                case 4:
                    return ' trillion';
                case 3:
                    return ' billion';
                case 2:
                    return ' million';
                case 1:
                    return ' thousand';
                case 0:
                    return '';
            }
        }

        protected static function _number_to_word_three_digits( $digit1, $digit2, $digit3 )
        {
            $output = '';

            if ( $digit1 == '0' && $digit2 == '0' && $digit3 == '0') {
                return '';
            }

            if ( $digit1 != '0' ) {
                $output .= self::_number_to_word_convert_digit( $digit1 ) . ' hundred';

                if ( $digit2 != '0' || $digit3 != '0' ) {
                    $output .= ' and ';
                }
            }

            if ( $digit2 != '0') {
                $output .= self::_number_to_word_two_digits( $digit2, $digit3 );
            } else if( $digit3 != '0' ) {
                $output .= self::_number_to_word_convert_digit( $digit3 );
            }

            return $output;
        }

        protected static function _number_to_word_two_digits( $digit1, $digit2 )
        {
            if ( $digit2 == '0' ) {
                switch ( $digit2 ) {
                    case '1':
                        return 'ten';
                    case '2':
                        return 'twenty';
                    case '3':
                        return 'thirty';
                    case '4':
                        return 'forty';
                    case '5':
                        return 'fifty';
                    case '6':
                        return 'sixty';
                    case '7':
                        return 'seventy';
                    case '8':
                        return 'eighty';
                    case '9':
                        return 'ninety';
                }
            } else if ( $digit1 == '1' ) {
                switch ( $digit2 ) {
                    case '1':
                        return 'eleven';
                    case '2':
                        return 'twelve';
                    case '3':
                        return 'thirteen';
                    case '4':
                        return 'fourteen';
                    case '5':
                        return 'fifteen';
                    case '6':
                        return 'sixteen';
                    case '7':
                        return 'seventeen';
                    case '8':
                        return 'eighteen';
                    case '9':
                        return 'nineteen';
                }
            } else {
                $second_digit = self::_number_to_word_convert_digit( $digit2 );

                switch ( $digit1 ) {
                    case '2':
                        return "twenty-{$second_digit}";
                    case '3':
                        return "thirty-{$second_digit}";
                    case '4':
                        return "forty-{$second_digit}";
                    case '5':
                        return "fifty-{$second_digit}";
                    case '6':
                        return "sixty-{$second_digit}";
                    case '7':
                        return "seventy-{$second_digit}";
                    case '8':
                        return "eighty-{$second_digit}";
                    case '9':
                        return "ninety-{$second_digit}";
                }
            }
        }

        protected static function _number_to_word_convert_digit( $digit )
        {
            switch ( $digit ) {
                case '0':
                    return 'zero';
                case '1':
                    return 'one';
                case '2':
                    return 'two';
                case '3':
                    return 'three';
                case '4':
                    return 'four';
                case '5':
                    return 'five';
                case '6':
                    return 'six';
                case '7':
                    return 'seven';
                case '8':
                    return 'eight';
                case '9':
                    return 'nine';
            }
        }

        /**
         * Transmit UTF-8 content headers if the headers haven't already been
         * sent
         *
         * @param   string  $content_type  The content type to send out,
         *                                 defaults to text/html
         * @return  bool
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function utf8_headers( $content_type = 'text/html' )
        {
            if ( ! headers_sent() ) {
                header( 'Content-type: ' . $content_type . '; charset=utf-8' );

                return TRUE;
            } else {
                return FALSE;
            }
        }

        /**
         * Transmit headers that force a browser to display the download file
         * dialog. Cross browser compatible. Only fires if headers have not
         * already been sent.
         *
         * @param   string  $filename  The name of the filename to display to
         *                             browsers
         * @param   string  $content   The content to output for the download.
         *                             If you don't specify this, just the
         *                             headers will be sent
         * @return  bool
         *
         * @link    http://www.php.net/manual/en/function.header.php#102175
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function force_download( $filename, $content = FALSE )
        {
            if ( ! headers_sent() ) {
                // Required for some browsers
                if ( ini_get( 'zlib.output_compression' ) ) {
                    @ini_set( 'zlib.output_compression', 'Off' );
                }

                header( 'Pragma: public' );
                header( 'Expires: 0' );
                header( 'Cache-Control: must-revalidate, post-check=0, pre-check=0' );

                // Required for certain browsers
                header( 'Cache-Control: private', FALSE );

                header( 'Content-Disposition: attachment; filename="' . basename( str_replace( '"', '', $filename ) ) . '";' );
                header( 'Content-Type: application/force-download' );
                header( 'Content-Transfer-Encoding: binary' );

                if ( $content ) {
                   header( 'Content-Length: ' . strlen( $content ) );
                }

                ob_clean();
                flush();

                if ( $content ) {
                    echo $content;
                }

                return TRUE;
            } else {
                return FALSE;
            }
        }

        /**
         * Sets the headers to prevent caching for the different browsers
         *
         * Different browsers support different nocache headers, so several
         * headers must be sent so that all of them get the point that no
         * caching should occur
         *
         * @return  bool
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function nocache_headers()
        {
            if ( ! headers_sent() ) {
                header( 'Expires: Wed, 11 Jan 1984 05:00:00 GMT' );
                header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' );
                header( 'Cache-Control: no-cache, must-revalidate, max-age=0' );
                header( 'Pragma: no-cache' );

                return TRUE;
            } else {
                return FALSE;
            }
        }

        /**
         * Generates a string of random characters
         *
         * @param   int   $length              The length of the string to
         *                                     generate
         * @param   bool  $human_friendly      Whether or not to make the
         *                                     string human friendly by
         *                                     removing characters that can be
         *                                     confused with other characters (
         *                                     O and 0, l and 1, etc)
         * @param   bool  $include_symbols     Whether or not to include
         *                                     symbols in the string. Can not
         *                                     be enabled if $human_friendly is
         *                                     true
         * @param   bool  $no_duplicate_chars  Whether or not to only use
         *                                     characters once in the string.
         * @return  string
         *
         * @throws  LengthException  If $length is bigger than the available
         *                           character pool and $no_duplicate_chars is
         *                           enabled
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function random_string( $length, $human_friendly = TRUE, $include_symbols = FALSE, $no_duplicate_chars = FALSE )
        {
            $nice_chars = 'ABCDEFGHJKLMNPQRSTUVWXYZabcdefhjkmnprstuvwxyz23456789';
            $all_an     = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890';
            $symbols    = '!@#$%^&*()~_-=+{}[]|:;<>,.?/"\'\\`';
            $string     = '';

            // Determine the pool of available characters based on the given parameters
            if ( $human_friendly ) {
                $pool = $nice_chars;
            } else {
                $pool = $all_an;

                if ( $include_symbols ) {
                    $pool .= $symbols;
                }
            }

            // Don't allow duplicate letters to be disabled if the length is
            // longer than the available characters
            if ( $no_duplicate_chars && strlen( $pool ) < $length ) {
                throw new LengthException( '$length exceeds the size of the pool and $no_duplicate_chars is enabled' );
            }

            // Convert the pool of characters into an array of characters and
            // shuffle the array
            $pool = str_split( $pool );
            shuffle( $pool );

            // Generate our string
            for ( $i = 0; $i < $length; $i++ ) {
                if ( $no_duplicate_chars ) {
                    $string .= array_shift( $pool );
                } else {
                    $string .= $pool[0];
                    shuffle( $pool );
                }
            }

            return $string;
        }

        /**
         * Validate an email address
         *
         * @param   string  $possible_email  An email address to validate
         * @return  bool
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function validate_email( $possible_email )
        {
            return (bool) filter_var( $possible_email, FILTER_VALIDATE_EMAIL );
        }

        /**
         * Return the URL to a user's gravatar
         *
         * @param   string  $email  The email of the user
         * @param   int     $size   The size of the gravatar
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function get_gravatar( $email, $size = 32 )
        {
			if ( self::is_https() ) {
				$url = 'https://secure.gravatar.com/';
			} else {
				$url = 'http://www.gravatar.com/';
            }

            $url .= 'avatar/' . md5( $email ) . '?s=' . (int) abs( $size );

			return $url;
        }

        /**
         * Turns all of the links in a string into HTML links
         *
         * @param   string  $text  The string to parse
         * @return  string
         *
         * @link    https://github.com/jmrware/LinkifyURL
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function linkify( $text )
        {
            $text = preg_replace( '/&apos;/', '&#39;', $text ); // IE does not handle &apos; entity!
            $section_html_pattern = '%# Rev:20100913_0900 github.com/jmrware/LinkifyURL
                # Section text into HTML <A> tags  and everything else.
                  (                              # $1: Everything not HTML <A> tag.
                    [^<]+(?:(?!<a\b)<[^<]*)*     # non A tag stuff starting with non-"<".
                  |      (?:(?!<a\b)<[^<]*)+     # non A tag stuff starting with "<".
                  )                              # End $1.
                | (                              # $2: HTML <A...>...</A> tag.
                    <a\b[^>]*>                   # <A...> opening tag.
                    [^<]*(?:(?!</a\b)<[^<]*)*    # A tag contents.
                    </a\s*>                      # </A> closing tag.
                  )                              # End $2:
                %ix';

            return preg_replace_callback( $section_html_pattern, array( __CLASS__, '_linkify_callback' ), $text );
        }

        /**
         * Callback for the preg_replace in the linkify() method
         *
         * @param   array  $matches  Matches from the preg_ function
         * @return  string
         *
         * @link    https://github.com/jmrware/LinkifyURL
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function _linkify( $text )
        {
            $url_pattern = '/# Rev:20100913_0900 github.com\/jmrware\/LinkifyURL
                # Match http & ftp URL that is not already linkified.
                # Alternative 1: URL delimited by (parentheses).
                (\() # $1 "(" start delimiter.
                ((?:ht|f)tps?:\/\/[a-z0-9\-._~!$&\'()*+,;=:\/?#[\]@%]+) # $2: URL.
                (\)) # $3: ")" end delimiter.
                | # Alternative 2: URL delimited by [square brackets].
                (\[) # $4: "[" start delimiter.
                ((?:ht|f)tps?:\/\/[a-z0-9\-._~!$&\'()*+,;=:\/?#[\]@%]+) # $5: URL.
                (\]) # $6: "]" end delimiter.
                | # Alternative 3: URL delimited by {curly braces}.
                (\{) # $7: "{" start delimiter.
                ((?:ht|f)tps?:\/\/[a-z0-9\-._~!$&\'()*+,;=:\/?#[\]@%]+) # $8: URL.
                (\}) # $9: "}" end delimiter.
                | # Alternative 4: URL delimited by <angle brackets>.
                (<|&(?:lt|\#60|\#x3c);) # $10: "<" start delimiter (or HTML entity).
                ((?:ht|f)tps?:\/\/[a-z0-9\-._~!$&\'()*+,;=:\/?#[\]@%]+) # $11: URL.
                (>|&(?:gt|\#62|\#x3e);) # $12: ">" end delimiter (or HTML entity).
                | # Alternative 5: URL not delimited by (), [], {} or <>.
                ( # $13: Prefix proving URL not already linked.
                (?: ^ # Can be a beginning of line or string, or
                | [^=\s\'"\]] # a non-"=", non-quote, non-"]", followed by
                ) \s*[\'"]? # optional whitespace and optional quote;
                | [^=\s]\s+ # or... a non-equals sign followed by whitespace.
                ) # End $13. Non-prelinkified-proof prefix.
                ( \b # $14: Other non-delimited URL.
                (?:ht|f)tps?:\/\/ # Required literal http, https, ftp or ftps prefix.
                [a-z0-9\-._~!$\'()*+,;=:\/?#[\]@%]+ # All URI chars except "&" (normal*).
                (?: # Either on a "&" or at the end of URI.
                (?! # Allow a "&" char only if not start of an...
                &(?:gt|\#0*62|\#x0*3e); # HTML ">" entity, or
                | &(?:amp|apos|quot|\#0*3[49]|\#x0*2[27]); # a [&\'"] entity if
                [.!&\',:?;]? # followed by optional punctuation then
                (?:[^a-z0-9\-._~!$&\'()*+,;=:\/?#[\]@%]|$) # a non-URI char or EOS.
                ) & # If neg-assertion true, match "&" (special).
                [a-z0-9\-._~!$\'()*+,;=:\/?#[\]@%]* # More non-& URI chars (normal*).
                )* # Unroll-the-loop (special normal*)*.
                [a-z0-9\-_~$()*+=\/#[\]@%] # Last char can\'t be [.!&\',;:?]
                ) # End $14. Other non-delimited URL.
                /imx';

            $url_replace = '$1$4$7$10$13<a href="$2$5$8$11$14">$2$5$8$11$14</a>$3$6$9$12';
            return preg_replace( $url_pattern, $url_replace, $text );
        }

        /**
         * Callback for the preg_replace in the linkify() method
         *
         * @param   array  $matches  Matches from the preg_ function
         * @return  string
         *
         * @link    https://github.com/jmrware/LinkifyURL
         *
         * @access  public
         * @since    1.0.000
         * @static
         */
        public static function _linkify_callback( $matches )
        {
            if ( isset( $matches[2] ) ) {
                return $matches[2];
            }

            return self::_linkify( $matches[1] );
        }

        /**
         * Return the current URL
         *
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function get_current_url()
        {
            $url = '';

            // Check to see if it's over https
            if ( self::is_https() ) {
                $url .= 'https://';
            } else {
                $url .= 'http://';
            }

            // Was a username or password passed?
            if ( isset( $_SERVER['PHP_AUTH_USER'] ) ) {
                $url .= $_SERVER['PHP_AUTH_USER'];

                if ( isset( $_SERVER['PHP_AUTH_PW'] ) ) {
                    $url .= ':' . $_SERVER['PHP_AUTH_PW'];
                }

                $url .= '@';
            }


            // We want the user to stay on the same host they are currently on,
            // but beware of security issues
            // see http://shiflett.org/blog/2006/mar/server-name-versus-http-host
            $url .= $_SERVER['HTTP_HOST'];

            // Is it on a non standard port?
            if ( $_SERVER['SERVER_PORT'] != 80 ) {
                $url .= ':' . $_SERVER['SERVER_PORT'];
            }

            // Get the rest of the URL
            if ( ! isset( $_SERVER['REQUEST_URI'] ) ) {

                // Microsoft IIS doesn't set REQUEST_URI by default
                $url .= substr( $_SERVER['PHP_SELF'], 1 );

                if ( isset( $_SERVER['QUERY_STRING'] ) ) {
                    $url .= '?' . $_SERVER['QUERY_STRING'];
                }
            } else {
                $url .= $_SERVER['REQUEST_URI'];
            }

            return $url;
        }

        /**
         * Returns the IP address of the client
         *
         * @param   bool  $trust_proxy_headers  Whether or not to trust the
         *                                      proxy headers HTTP_CLIENT_IP
         *                                      and HTTP_X_FORWARDED_FOR. ONLY
         *                                      use if your server is behind a
         *                                      proxy that sets these values
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function get_client_ip( $trust_proxy_headers = FALSE )
        {
            if ( ! $trust_proxy_headers ) {
                return $_SERVER['REMOTE_ADDR'];
            }

            if ( ! empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
                $ip = $_SERVER['HTTP_CLIENT_IP'];
            } else if ( ! empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
                $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
            } else {
                $ip = $_SERVER['REMOTE_ADDR'];
            }

            return $ip;
        }

        /**
         * Truncate a string to a specified length without cutting a word off
         *
         * @param   string  $string  The string to truncate
         * @param   int     $length  The length to truncate the string to
         * @param   string  $append  Text to append to the string IF it gets
         *                           truncated, defaults to '...'
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function safe_truncate( $string, $length, $append = '...' )
        {
            $ret        = substr( $string, 0, $length );
            $last_space = strrpos( $ret, ' ' );

            if ( $last_space !== FALSE && $string != $ret ) {
                $ret     = substr( $ret, 0, $last_space );
            }

            if ( $ret != $string ) {
                $ret .= $append;
            }

            return $ret;
        }

        /**
         * Returns the ordinal version of a number (appends th, st, nd, rd)
         *
         * @param   string  $number  The number to append an ordinal suffix to
         * @return  string
         *
         * @link    http://phpsnips.com/snippet.php?id=37
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function ordinal( $number )
        {
            $test_c = abs ($number ) % 10;

            $ext = ( ( abs( $number ) % 100 < 21 && abs( $number ) % 100 > 4 ) ? 'th' : ( ( $test_c < 4 ) ? ( $test_c < 3 ) ? ( $test_c < 2 ) ? ( $test_c < 1 ) ? 'th' : 'st' : 'nd' : 'rd' : 'th' ) );

            return $number . $ext;
        }

        /**
         * Returns the file permissions as a nice string, like -rw-r--r--
         *
         * @param   string  $file  The name of the file to get permissions form
         * @return  string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function full_permissions( $file )
        {
            $perms = fileperms( $file );

            if ( ( $perms & 0xC000 ) == 0xC000 ) {
                // Socket
                $info = 's';
            } else if ( ( $perms & 0xA000 ) == 0xA000 ) {
                // Symbolic Link
                $info = 'l';
            } else if ( ( $perms & 0x8000 ) == 0x8000 ) {
                // Regular
                $info = '-';
            } else if ( ( $perms & 0x6000 ) == 0x6000 ) {
                // Block special
                $info = 'b';
            } else if ( ( $perms & 0x4000 ) == 0x4000 ) {
                // Directory
                $info = 'd';
            } else if ( ( $perms & 0x2000 ) == 0x2000 ) {
                // Character special
                $info = 'c';
            } else if ( ( $perms & 0x1000 ) == 0x1000 ) {
                // FIFO pipe
                $info = 'p';
            } else {
                // Unknown
                $info = 'u';
            }

            // Owner
            $info .= ( ( $perms & 0x0100 ) ? 'r' : '-' );
            $info .= ( ( $perms & 0x0080 ) ? 'w' : '-' );
            $info .= ( ( $perms & 0x0040 ) ?
                        ( ( $perms & 0x0800 ) ? 's' : 'x' ) :
                        ( ( $perms & 0x0800 ) ? 'S' : '-' ) );

            // Group
            $info .= ( ( $perms & 0x0020 ) ? 'r' : '-' );
            $info .= ( ( $perms & 0x0010 ) ? 'w' : '-' );
            $info .= ( ( $perms & 0x0008 ) ?
                        ( ( $perms & 0x0400 ) ? 's' : 'x' ) :
                        ( ( $perms & 0x0400 ) ? 'S' : '-' ) );

            // World
            $info .= ( ( $perms & 0x0004 ) ? 'r' : '-' );
            $info .= ( ( $perms & 0x0002 ) ? 'w' : '-' );
            $info .= ( ( $perms & 0x0001 ) ?
                        ( ( $perms & 0x0200 ) ? 't' : 'x' ) :
                        ( ( $perms & 0x0200 ) ? 'T' : '-' ) );

            return $info;
        }

        /**
         * Returns the first element in an array
         *
         * @param   array  $array  The array
         * @return  mixed
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_first( array $array )
        {
            return reset( $array );
        }

        /**
         * Returns the last element in an array
         *
         * @param   array  $array  The array
         * @return  mixed
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_last( array $array )
        {
            return end( $array );
        }

        /**
         * Returns the first key in an array
         *
         * @param   array  $array  The array
         * @return  int|string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_first_key( array $array )
        {
            reset( $array );

            return key( $array );
        }

        /**
         * Returns the last key in an array
         *
         * @param   array  $array  The array
         * @return  int|string
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_last_key( array $array )
        {
            end( $array );

            return key( $array );
        }

        /**
         * Flattens a potentially multi-dimensional array into a one
         * dimensional array
         *
         * @param   array  $array         The array to flatten
         * @param   bool   preserve_keys  Whether or not to preserve array
         *                                keys. Keys from deeply nested arrays
         *                                will overwrite keys from shallowy
         *                                nested arrays
         * @return  array
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_flatten( array $array, $preserve_keys = TRUE )
        {
            $flattened = array();

            foreach ( $array as $key => $value ) {
                if ( is_array( $value ) ) {
                    $flattened = array_merge( $flattened, self::array_flatten( $value, $preserve_keys ) );
                } else {
                    if ( $preserve_keys ) {
                        $flattened[$key] = $value;
                    } else {
                        $flattened[] = $value;
                    }
                }
            }

            return $flattened;
        }

        /**
         * Accepts an array, and returns an array of values from that array as
         * specified by $field. For example, if the array is full of objects
         * and you call util::array_pluck( $array, 'name' ), the function will
         * return an array of values from $array[]->name
         *
         * @param   array   $array             An array
         * @param   string  $field             The field to get values from
         * @param   bool    $preserve_keys     Whether or not to preserve the
         *                                     array keys
         * @param   bool    $remove_nomatches  If the field doesn't appear to
         *                                     be set, remove it from the array
         * @return  array
         *
         * @link    http://codex.wordpress.org/Function_Reference/wp_list_pluck
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_pluck( array $array, $field, $preserve_keys = TRUE, $remove_nomatches = TRUE )
        {
            $new_list = array();

            foreach ( $array as $key => $value ) {
                if ( is_object( $value ) ) {
                    if ( isset( $value->{$field} ) ) {
                        if ( $preserve_keys ) {
                            $new_list[$key] = $value->{$field};
                        } else {
                            $new_list[] = $value->{$field};
                        }
                    } else if ( ! $remove_nomatches ) {
                        $new_list[$key] = $value;
                    }
                } else {
                    if ( isset( $value[$field] ) ) {
                        if ( $preserve_keys ) {
                            $new_list[$key] = $value[$field];
                        } else {
                            $new_list[] = $value[$field];
                        }
                    } else if ( ! $remove_nomatches ) {
                        $new_list[$key] = $value;
                    }
                }
            }

            return $new_list;
        }

        /**
         * Searches for a given value in an array of arrays, objects and scalar
         * values. You can optionally specify a field of the nested arrays and
         * objects to search in
         *
         * @param   array   $array   The array to search
         * @param   scalar  $search  The value to search for
         * @param   string  $field   The field to search in, if not specified
         *                           all fields will be searched
         * @return  bool|scalar      False on failure or the array key on
         *                           success
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_search_deep( array $array, $search, $field = FALSE )
        {
            // *grumbles* stupid PHP type system
            $search = (string) $search;

            foreach ( $array as $key => $elem ) {

                // *grumbles* stupid PHP type system
                $key = (string) $key;

                if ( $field ) {
                    if ( is_object( $elem ) && $elem->{$field} === $search ) {
                        return $key;
                    } else if ( is_array( $elem ) && $elem[$field] === $search ) {
                        return $key;
                    } else if ( is_scalar( $elem ) && $elem === $search ) {
                        return $key;
                    }
                } else {
                    if ( is_object( $elem ) ) {
                        $elem = (array) $elem;

                        if ( in_array( $search, $elem ) ) {
                            return $key;
                        }
                    } else if ( is_array( $elem ) && in_array( $search, $elem ) ) {
                        return array_search( $search, $elem );
                    } else if ( is_scalar( $elem ) && $elem === $search ) {
                        return $key;
                    }
                }
            }

            return FALSE;
        }

        /**
         * Returns an array containing all the elements of arr1 after applying
         * the callback function to each one
         *
         * @param   string  $callback      Callback function to run for each
         *                                 element in each array
         * @param   array   $array         An array to run through the callback
         *                                 function
         * @param   bool    $on_nonscalar  Whether or not to call the callback
         *                                 function on nonscalar values
         *                                 (Objects, resources, etc)
         * @return  array
         *
         * @access  public
         * @since   1.0.000
         * @static
         */
        public static function array_map_deep( array $array, $callback, $on_nonscalar = FALSE )
        {
            foreach ( $array as $key => $value ) {
                if ( is_array( $value ) ) {
                    $args = array( $value, $callback, $on_nonscalar );
                    $array[$key] = call_user_func_array( array( __CLASS__, __FUNCTION__ ), $args );
                } else if ( is_scalar( $value ) || $on_nonscalar ) {
                    $array[$key] = call_user_func( $callback, $value );
                }
            }

            return $array;
        }
    }
}