Zend_Config | Zend_Config Programmer's Reference Guide | Theory of Operation
# Introduction Zend_Config is designed to simplify the access to, and the use of, configuration data within applications. It provides a nested object property based user interface for accessing this configuration data within application code. The configuration data may come from a variety of media supporting hierarchical data storage. Currently Zend_Config provides adapters for configuration data that are stored in text files with Zend_Config_Ini and Zend_Config_Xml. Example #1 Using Zend_Config Normally it is expected that users would use one of the adapter classes such as Zend_Config_Ini or Zend_Config_Xml, but if configuration data are available in a PHP array, one may simply pass the data to the Zend_Config constructor in order to utilize a simple object-oriented interface: // Given an array of configuration data $configArray = array( 'webhost' => 'www.example.com', 'database' => array( 'adapter' => 'pdo_mysql', 'params' => array( 'host' => 'db.example.com', 'username' => 'dbuser', 'password' => 'secret', 'dbname' => 'mydatabase' ) ) ); // Create the object-oriented wrapper upon the configuration data $config = new Zend_Config($configArray); // Print a configuration datum (results in 'www.example.com') echo $config->webhost; // Use the configuration data to connect to the database $db = Zend_Db::factory($config->database->adapter, $config->database->params->toArray()); // Alternative usage: simply pass the Zend_Config object. // The Zend_Db factory knows how to interpret it. $db = Zend_Db::factory($config->database); As illustrated in the example above, Zend_Config provides nested object property syntax to access configuration data passed to its constructor. Along with the object oriented access to the data values, Zend_Config also has get() which will return the supplied default value if the data element doesn't exist. For example: $host = $config->database->get('host', 'localhost'); Example #2 Using Zend_Config with a PHP Configuration File It is often desirable to use a pure PHP-based configuration file. The following code illustrates how easily this can be accomplished: // config.php return array( 'webhost' => 'www.example.com', 'database' => array( 'adapter' => 'pdo_mysql', 'params' => array( 'host' => 'db.example.com', 'username' => 'dbuser', 'password' => 'secret', 'dbname' => 'mydatabase' ) ) ); // Configuration consumption $config = new Zend_Config(require 'config.php'); // Print a configuration datum (results in 'www.example.com') echo $config->webhost;
Zend_Config | Zend_Config Programmer's Reference Guide | Theory of Operation