Entry Script

The 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, the entry script of a Yii application contains code that is as simple as this:

// 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 ¶

A Yii application can run in either debug or production mode, as determined by the value of the constant 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 the application in debug mode is less efficient because it keeps many internal logs. On the other hand, debug mode is also more helpful during the development stage because it provides richer debugging information when an error occurs.