Phalcon - Configuration

The config folder of the web application includes the following files −

• config.php
• loader.php
• services.php

config.php

It includes the configurations for database connectivity and routing as per the directory path.

<?php 

/*
   * Modified: preppend directory path of current file, 
      because of this file own different ENV under between Apache and command line. 
   * NOTE: please remove this comment. 
*/ 

defined('BASE_PATH') || define('BASE_PATH', getenv('BASE_PATH') ?: 
   realpath(dirname(__FILE__) . '/../..')); 
defined('APP_PATH') || define('APP_PATH', BASE_PATH . '/app');  

return new \Phalcon\Config([ 
   'database' => [ 
      'adapter'     => 'Mysql', 
      'host'        => 'localhost', 
      'username'    => 'root', 
      'password'    => '', 
      'dbname'      => 'test', 
      'charset'     => 'utf8', 
   ], 
   'application' => [ 
      'appDir'         => APP_PATH . '/', 
      'controllersDir' => APP_PATH . '/controllers/', 
      'modelsDir'      => APP_PATH . '/models/', 
      'migrationsDir'  => APP_PATH . '/migrations/', 
      'viewsDir'       => APP_PATH . '/views/', 
      'pluginsDir'     => APP_PATH . '/plugins/', 
      'libraryDir'     => APP_PATH . '/library/', 
      'cacheDir'       => BASE_PATH . '/cache/', 
      'baseUri'        => '/demo1/', 
   ] 
]);

loader.php

It extends the existing class of \Phalcon\Loader(). The loader class registers the directories which requires web application.

<?php  
$loader = new \Phalcon\Loader();  

/** 
   * We're a registering a set of directories taken from the configuration file 
*/ 

$loader->registerDirs( [ 
      $config->application->controllersDir, 
      $config->application->modelsDir 
   ] 
)->register(); 

services.php

This file associates all the functions which implement the services of a web project. It implements Phalcon\Di interface. It also implements a dependency injection of the services by loading them.
Basically, services.php file inside the config folder acts as a container of all services. This interface helps in initializing all the services like database connection, setting up cookies, creating a new session, or connecting with NoSQL database.

<?php  

use Phalcon\Mvc\View; 
use Phalcon\Mvc\View\Engine\Php as PhpEngine; 
use Phalcon\Mvc\Url as UrlResolver; 
use Phalcon\Mvc\View\Engine\Volt as VoltEngine; 
use Phalcon\Mvc\Model\Metadata\Memory as MetaDataAdapter; 
use Phalcon\Session\Adapter\Files as SessionAdapter; 
use Phalcon\Flash\Direct as Flash;   

/** 
   * Shared configuration service 
*/ 

$di->setShared('config', function () { 
   return include APP_PATH . "/config/config.php"; 
});  

/** 
   * The URL component is used to generate all kind of urls in the application 
*/ 

$di->setShared('url', function () { 
      $config = $this->getConfig(); 
      $url = new UrlResolver(); 
      $url->setBaseUri($config->application->baseUri);  
   return $url; 
});  

/** 
   * Setting up the view component 
*/ 
   
$di->setShared('view', function () { 
   $config = $this->getConfig();  
   $view = new View(); 
   $view->setDI($this); 
   $view->setViewsDir($config->application->viewsDir);  
   
   $view->registerEngines([ 
      '.volt' => function ($view) { 
         $config = $this->getConfig();  
         $volt = new VoltEngine($view, $this);  
         
         $volt->setOptions([ 
            'compiledPath' => $config->application->cacheDir, 
            'compiledSeparator' => '_' 
         ]);  
         return $volt; 
      }, 
      '.phtml' => PhpEngine::class  
   ]);  
   return $view; 
}); 

/** 
   * Database connection is created based in the parameters defined in the configuration 
      file 
*/ 

$di->setShared('db', function () { 
   $config = $this->getConfig();  
   $class = 'Phalcon\Db\Adapter\Pdo\\' . $config->database->adapter; 
   $connection = new $class([ 
      'host'     => $config->database->host, 
      'username' => $config->database->username, 
      'password' => $config->database->password, 
      'dbname'   => $config->database->dbname, 
      'charset'  => $config->database->charset 
   ]);  
   return $connection; 
});