下面的代码实现了一个表单输入的过滤过程，类似于Zend_Form_Element功能。
<?php
/** * AbstractColleague. */
interface Filter {
public function filter($value);
}
/**
* Colleague. We decide in the implementation phase
* that Colleagues should not know the next Colleague
* in the chain, resorting to a Mediator to link them together.
* This choice succesfully avoids a base abstract class
* for Filters.
* Remember that this is an example: it is not only
* Chain of Responsibility that can be alternatively implemented
* as a Mediator.
*/
class TrimFilter implements Filter {
public function filter($value)
{
return trim($value);
}
}
/** * AbstractColleague. */
interface Filter {
public function filter($value);
}
/**
* Colleague. We decide in the implementation phase
* that Colleagues should not know the next Colleague
* in the chain, resorting to a Mediator to link them together.
* This choice succesfully avoids a base abstract class
* for Filters.
* Remember that this is an example: it is not only
* Chain of Responsibility that can be alternatively implemented
* as a Mediator.
*/
class TrimFilter implements Filter {
public function filter($value)
{
return trim($value);
}
}
/**
* Colleague.
*/
class NullFilter implements Filter {
* Colleague.
*/
class NullFilter implements Filter {
public function filter($value) {
return $value ? $value : '';
}
}
/**
* Colleague.
*/
class HtmlEntitiesFilter implements Filter {
public function filter($value) {
return htmlentities($value);
}
}
return $value ? $value : '';
}
}
/**
* Colleague.
*/
class HtmlEntitiesFilter implements Filter {
public function filter($value) {
return htmlentities($value);
}
}
/**
* The Mediator. We avoid referencing it from ConcreteColleagues
* and so the need for an interface. We leave the implementation
* of a bidirectional channel for the Observer pattern's example.
* This class responsibility is to store the value and coordinate
* filters computation when they have to be applied to the value.
* Filtering responsibilities are obviously a concern of
* the Colleagues, which are Filter implementations.
*/
class InputElement {
protected $_filters;
protected $_value;
public function addFilter(Filter $filter)
{
$this->_filters[] = $filter;
return $this;
}
public function setValue($value) {
$this->_value = $this->_filter($value);
}
protected function _filter($value) {
foreach ($this->_filters as $filter)
{
$value = $filter->filter($value);
}
return $value;
} public function getValue() {
return $this->_value;
}
}
$input = new InputElement();
$input->addFilter(new NullFilter())
* The Mediator. We avoid referencing it from ConcreteColleagues
* and so the need for an interface. We leave the implementation
* of a bidirectional channel for the Observer pattern's example.
* This class responsibility is to store the value and coordinate
* filters computation when they have to be applied to the value.
* Filtering responsibilities are obviously a concern of
* the Colleagues, which are Filter implementations.
*/
class InputElement {
protected $_filters;
protected $_value;
public function addFilter(Filter $filter)
{
$this->_filters[] = $filter;
return $this;
}
public function setValue($value) {
$this->_value = $this->_filter($value);
}
protected function _filter($value) {
foreach ($this->_filters as $filter)
{
$value = $filter->filter($value);
}
return $value;
} public function getValue() {
return $this->_value;
}
}
$input = new InputElement();
$input->addFilter(new NullFilter())
->addFilter(new TrimFilter())
->addFilter(new HtmlEntitiesFilter());
$input->setValue(' You should use the <h1>-<h6> tags for your headings.');
echo $input->getValue(), "\n";
->addFilter(new HtmlEntitiesFilter());
$input->setValue(' You should use the <h1>-<h6> tags for your headings.');
echo $input->getValue(), "\n";
