example.php

<?php

require 'Nette/loader.php';
require 'stringFluent.php';

$string = string("ahoj já jsem petr")->capitalize();
echo $string."\n";
echo $string->webalize();

stringFluent.php

<?php

use Nette\Object;
use Nette\String;

/**
 * String fluent
 * @copyright  Copyright (c) 2010 Martin Sadový
 * TODO: startsWith, endsWith, compare, indent, padLeft, padRight // yes or no?
 * TODO: clone or reference?
 */
class StringFluent extends Object
{
        /**
         * @var string
         */
        protected $content;

        public function __construct($content)
        {
                if(is_object($content) AND method_exists($content, '__toString') ){
                    $this->content = String::fixEncoding($content->__toString());

                }elseif(is_scalar($content)){
                    $this->content = String::fixEncoding((string) $content);

                }else{
                    throw new InvalidArgumentException("The argument must be either scalar or an object with method __toString, " . gettype($val) ." given.");
                }
        }


        
        /****** Modification methods ******/

        /**
         * Convert to lower case.
         * @return StringFluent
         */
        public function lower()
        {
                $this->content = String::lower($this->content);
                return $this;
        }



        /**
         * Convert to upper case.
         * @return StringFluent
         */
        public function upper()
        {
                $this->content = String::upper($this->content);
                return $this;
        }



        /**
         * Capitalize string.
         * @return StringFluent
         */
        public function capitalize()
        {
                $this->content = String::capitalize($this->content);
                return $this;
        }



        /**
         * Converts to web safe characters [a-z0-9-] text.
         * @param  string  ASCII
         * @param  bool
         * @return StringFluent
         */
        public function webalize($charlist = NULL, $lower = TRUE)
        {
                $this->content = String::webalize($this->content, $charlist, $lower);
                return $this;
        }



        /**
         * Capitalize string.
         * @param  int
         * @param  string  UTF-8 encoding
         * @return StringFluent
         */
        public function truncate($maxLength, $append = NULL)
        {
                $this->content = $append === NULL ? String::truncate($this->content, $maxLength) : String::truncate($this->content, $maxLength, $append);
                return $this;
        }



        /**
         * Removes special controls characters and normalizes line endings and spaces.
         * @return StringFluent
         */
        public function normalize()
        {
                $this->content = String::normalize($this->content);
                return $this;
        }


        /**
         * Strips whitespace.
         * @param  string
         * @return StringFluent
         */
        public function trim($charlist = NULL)
        {
                $this->content = $charlist === NULL ? String::trim($this->content) : String::trim($this->content, $charlist);
                return $this;
        }



        /****** Regular methods ******/

        /**
         * Splits string by a regular expression.
         * @param  string
         * @param  int
         * @return array
         */
        public function split($pattern, $flags = 0)
        {
                return String::split($this->content, $pattern, $flags);
        }



        /**
         * Performs a regular expression match.
         * @param  string
         * @param  int
         * @param  int
         * @return mixed
         */
        public function match($pattern, $flags = 0, $offset = 0)
        {
                return String::match($this->content, $pattern, $flags, $offset);
        }



        /**
         * Performs a global regular expression match.
         * @param  string
         * @param  int  (PREG_SET_ORDER is default)
         * @param  int
         * @return array
         */
        public function matchAll($pattern, $flags = 0, $offset = 0)
        {
                return String::matchAll($this->content, $pattern, $flags, $offset);
        }



        /**
         * Perform a regular expression search and replace.
         * @param  string|array
         * @param  string|callback
         * @param  int
         * @return StringFluent
         */
        public function replace($pattern, $replacement = NULL, $limit = -1)
        {
                $this->content = String::replace($this->content, $pattern, $replacement, $limit);
                return $this;
        }



        /****** Return methods ******/

        /**
         * Return length string
         * @return int
         */
        public function getLength()
        {
                return String::length($this->content);
        }



        /**
         * Return string
         * @return string
         */
        public function __toString()
        {
                return $this->content;
        }
}

/**
 * @return StringFluent
 */
function string($string)
{
        return new StringFluent($string);
}