004_config.md

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Config

Use a Config Class to construct your business domain classes by injecting the data from the Config using the Factory when you do the creation of your domain classes.

In order to achieve that, you need to create a gacela.json file in your application root with the following values:

gacela.json examples

Using PHP config files:

{
  "config": {
    "type": "php",
    "path": "config/*.php",
    "path_local": "config/local.php"
  }
}

Using .env config files:

{
  "config": {
    "type": "env",
    "path": ".env*",
    "path_local": ".env.local"
  }
}

Or even multiple types of config files:

{
  "config": [
    {
      "type": "php",
      "path": "config/*.php",
      "path_local": "config/local.php"
    },
    {
      "type": "env",
      "path": ".env*",
      "path_local": ".env.local"
    }
  ]
}

• "type": possible values php or env
• "path": the path of the folder which contains your application configuration. You can use ? or * in order to match 1 or multiple characters. Check glob() function for more info.
• "path_local": this is the last file loaded, which means, it will override the previous configuration, so you can add it to your .gitignore and set your own local config values.

---

This is tightly coupled with the infrastructure layer, because there is I/O involved. It's not bad itself, you just need to be aware of potential risks, though. Don't access data from your config files (files under the gacela.json path directory) directly in your domain services. In this way, you would couple your logic with infrastructure code, and not be able to unit test it.

An example

# gacela.json
{
  "config": {
    "type": "php",
    "path": "config/*.php",
    "path_local": "config/local.php"
  }
}

# config/default.php
use src\Calculator\Config;

return [
    Config::MAX_ADDITIONS => 20,
];

# src/Calculator/Config.php
final class Config extends AbstractConfig
{
    public const MAX_ADDITIONS = 'MAX_ADDITIONS';

    public function getMaxAdditions(): int
    {
        return $this->get(self::MAX_ADDITIONS, $default = 0);
    }
}

# src/Calculator/Factory.php
/**
 * @method Config getConfig()
 */
final class Factory extends AbstractFactory
{
    public function createAdder(): AdderInterface
    {
        return new Adder(
            $this->getConfig()->getMaxAdditions()
        );
    }
}

<< Factory | Dependency Provider >>