Filter Chains | Zend_Filter Programmer's Reference Guide | Zend_Filter_Input
# Writing Filters Zend_Filter supplies a set of commonly needed filters, but developers will often need to write custom filters for their particular use cases. The task of writing a custom filter is facilitated by implementing Zend_Filter_Interface. Zend_Filter_Interface defines a single method, filter(), that may be implemented by user classes. An object that implements this interface may be added to a filter chain with Zend_Filter::addFilter(). The following example demonstrates how to write a custom filter: class MyFilter implements Zend_Filter_Interface { public function filter($value) { // perform some transformation upon $value to arrive on $valueFiltered return $valueFiltered; } } To add an instance of the filter defined above to a filter chain: $filterChain = new Zend_Filter(); $filterChain->addFilter(new MyFilter());
Filter Chains | Zend_Filter Programmer's Reference Guide | Zend_Filter_Input