Entry Script

Entry script is the bootstrap PHP script that handles user requests initially. It is the only PHP script that end users can directly request to execute.

In most cases, entry script of an Yii application contains the code that is as simple as follows,

// remove the following line when in production mode
defined('YII_DEBUG') or define('YII_DEBUG',true);
// include Yii bootstrap file
require_once('path/to/yii/framework/yii.php');
// create application instance and run
$configFile='path/to/config/file.php';
Yii::createWebApplication($configFile)->run();

The script first includes the Yii framework bootstrap file yii.php. It then creates a Web application instance with the specified configuration and runs it.

1. Debug Mode ¶

An Yii application can run in either debug or production mode according to the constant value YII_DEBUG. By default, this constant value is defined as false, meaning production mode. To run in debug mode, define this constant as true before including the yii.php file. Running application in debug mode is less efficient because it keeps many internal logs. On the other hand, debug mode is also more helpful during development stage because it provides richer debugging information when error occurs.