Filter usage example of zf framework_PHP tutorial

/* Simple usage and operation of the filter ( )*/

require_once("Zend/Loader.php");
//Introducing Filter's string conversion to lowercase and uppercase classes
Zend_Loader::loadClass("Zend_Filter_StringToLower");
Zend_Loader:: loadClass("Zend_Filter_StringToUpper");
//Instantiate string to lowercase and uppercase classes
$Filter = new Zend_Filter_StringToLower();
$Filter2 = new Zend_Filter_StringToUpper();
// Set the string that needs to be converted
$Temp = 'ZHOUWUJIE  zhouwujie  ;
//Conversion method filter();
$Result = $Filter -> filter($Temp);
$ Result2 = $Filter2 -> filter($Temp);
echo $Result;
echo $Result2;
?>

/*How to use and operate the filter (filter chain)*/
require_once("Zend/Loader.php");
//The use of filter chain to load filters and filter method classes
Zend_Loader::loadClass("Zend_Filter ");
Zend_Loader::loadClass("Zend_Filter_Htmlentities");
Zend_Loader::loadClass("Zend_Filter_StripTags");
//Add the filter after instantiating the filter addFilter(new filter method class name ())
$Filter = new Zend_Filter();
$Filter //-> addFilter(new Zend_Filter_Htmlentities());
-> addFilter(new Zend_Filter_StripTags());
$ String = "Link";
$Result = $Filter -> filter($String);
echo $Result;
?> ;

/*Custom filter*/
require_once("Zend/Loader.php");
Zend_Loader::loadClass("Zend_Filter_Interface");
class MyFilter implements Zend_Filter_Interface
{
public function filter($value)
{
$List = array('yellow','gambling','poison');
foreach ($List as $k => $v)
{
$value = str_replace($v , '*', $value);
}
return $value;
}
}
$Filter = new MyFilter();
$String = 'This message is Pornographic content';
$String2 = 'He went gambling today';
$String3 = 'He went to take drugs today';
echo "

---

Filter content
";
echo $Filter -> filter($String) . "
";
echo $Filter -> filter($String2) . "
";
echo $Filter - > filter($String3) . "
";
?>