temp method

<?php
abstract class TemplateAbstract
{
    //the template method
    // sets up a general algorithm for the whole class
    public final function showBookTitleInfo($book_in)
    {
        $title           = $book_in->getTitle();
        $author          = $book_in->getAuthor();
        $processedTitle  = $this->processTitle($title);
        $processedAuthor = $this->processAuthor($author);
        if (NULL == $processedAuthor) {
            $processed_info = $processedTitle;
        } else {
            $processed_info = $processedTitle . ' by ' . $processedAuthor;
        }
        return $processed_info;
    }
    //the primitive operation
    // this function must be overridded
    abstract function processTitle($title);
    //the hook operation
    // this function may be overridden,
    // but does nothing if it is not
    function processAuthor($author)
    {
        return NULL;
    }
}
class TemplateExclaim extends TemplateAbstract
{
    function processTitle($title)
    {
        return Str_replace(' ', '!!!', $title);
    }
    function processAuthor($author)
    {
        return Str_replace(' ', '!!!', $author);
    }
}
class TemplateStars extends TemplateAbstract
{
    function processTitle($title)
    {
        return Str_replace(' ', '*', $title);
    }
}
class Book
{
    private $author;
    private $title;
    function __construct($title_in, $author_in)
    {
        $this->author = $author_in;
        $this->title  = $title_in;
    }
    function getAuthor()
    {
        return $this->author;
    }
    function getTitle()
    {
        return $this->title;
    }
    function getAuthorAndTitle()
    {
        return $this->getTitle() . ' by ' . $this->getAuthor();
    }
}
writeln('BEGIN TESTING TEMPLATE PATTERN');
writeln('');
$book            = new Book('PHP for Cats', 'Larry Truett');
$exclaimTemplate = new TemplateExclaim();
$starsTemplate   = new TemplateStars();
writeln('test 1 - show exclaim template');
writeln($exclaimTemplate->showBookTitleInfo($book));
writeln('');
writeln('test 2 - show stars template');
writeln($starsTemplate->showBookTitleInfo($book));
writeln('');
writeln('END TESTING TEMPLATE PATTERN');
function writeln($line_in)
{
    echo $line_in . "<br/>";
}
?>