The Configurable Interface
August 4th, 2008Oftentimes you need to configure an object quickly. Generally, the API offers a series of mutator methods which allow for changing properties within the instance. Where this becomes problematic, is when you have several instances to manage with similar or identical configurations.
An ideal implementation would look something like this:
$configuration = array(
'foo' => 123,
'bar' => true
);
$one = new Thing;
$one->configure($configuration);
$two = new Thing;
$two->configure($configuration);
Panda_Configurable_Interface offers a standardized solution: Simply implement the interface and add a configure() method to your class.
A Quick Example
The interface has a single requirement: the configure() method:
public function configure(array $configuration = array());
As you can see, your implementation will need to accept an array as its only parameter. The idea is that the configuration array would contain name and value pairs representing configuration directives (although it could really contain anything) for your class.
Here’s an example from the recently updated Panda_Loader_Abstract class:
public function configure(array $configuration = array())
{
if (array_key_exists('namespace', $configuration)) {
$this->setNamespace($configuration['namespace']);
}
if (array_key_exists('baseDir', $configuration)) {
$this->setBaseDir($configuration['baseDir']);
}
if (array_key_exists('load', $configuration)) {
if (is_string($configuration['load'])) {
$this->load($configuration['load']);
}
elseif (is_array($configuration['load'])) {
foreach ($configuration['load'] as $className) {
$this->load($className);
}
}
}
}
And on the front, it looks like this:
$Loader = My_Loader::singleton();
$Loader->configure(array(
'baseDir' => realpath('../lib'),
'namespace' => 'Blog',
'load' => array(
'FrontController',
'Request',
'Route',
'Controller',
'Model',
'View'
)
));