# CakePHP3 separate config file for each environment

I’ll write how to separate config file in CakePHP3 version 3.0.9. As for FuelPHP, you can add setting file into app/config/development, etc.

In the case when creating setting file in CakePHP3 for each environment, I’ll recommend you to create the directory config/development and put setting files in it, and modify configure loading code.

## Modified Code

Add one line with Configure::load into config/bootstrap.php. In the following code, it’s forth line. Suppoted that $environment is set. You should define it somewhere. At the forth line, it will merge setting file config/{$development}/app.php into config/app.php.

You can add any other conditional statement like if or switch.

## Explanation

### What does Configure do?

According to bootstrap.php, Configure::config and Configure::load seems to concern loading setting file. Let’s look at these functions.

Class Configure is defined at vendor/cakephp/cakephp/src/Core/Configure.php.

#### Configure::config

According to the comment, this method adds an engine. First parameter is the key to identify added engines, seconed one is the instance of the engine. You know, if you set the engine with the same name twice or more times, the setting is overwritten by last one.

bootstrap.php adds engine new PhpConfig() as default one, with Configure::config('default', new PhpConfig());.

#### Configure::load

The method loads setting with the engine set with Configure::config.

First parameter specify the file to be load. When you use /, it means directory separator.

Second parameter specify the engine to handle settings, which is set with Configure::config. The identify key of the engine is expressed as $name in Configure::config, but it’s $config in here. On specifying the engine unset, return false.

Third parameter defines to merge or to overwrite. I’ll set it true, because common setting in all environments should be written in one file.

So, you can merge setting file with Configure::load(filepath, 'default', true). You know I didn’t explain the detail like Hash::merge.

### If load not existing file?

You can know what will occur when you try it. But let’s look at what procedure works. According to bootstrap.php and Configure::load, the setting file will be load with read method in PhpConfig. PhpConfig is defined at vendor/cakephp/cakephp/src/Core/Configure.php.

It says error will be occurred. The variable \$config seems a relic on the past