ZF External Config Module

This module provides the logic and abstraction for loading and merging application's configuration from external sources., _(*1)

The module itself does not have any external provider yet, providers can be installed via Composer or written it your application's code., _(*2)

Installation

Require module with Composer:, _(*3)

composer require rstgroup/zf-external-config-module

The next step is adding module to ZF system configuration (config/application.config.php):, _(*4)

return [
    'modules' => [
        (...),
        'RstGroup\ZfExternalConfigModule',
    ],
    (...)
]

Adding providers

To load configuration from external source, the providers should be registered in your app's configuration:, _(*5)

return [
    'rst_group' => [
        'external_config' => [
            'providers' => [
                'YourProviderService' => true,
            ],
            'service_manager' => [
                'factories' => [
                    'YourProviderService' => YourProvidersServiceFactory::class
                ]
            ]
        ],
    ]
];

The module skims through enabled providers defined in:, _(*6)

rst_group.external_config.providers
````
and creates them using Inner Service Manager.

### Enabling and disabling providers

Disabled providers, even though they are defined, don't participate in creation of
final configuration. 

Here's an example how to mark defined provider enabled or disabled:

```php
return [
    'rst_group' => [
        'external_config' => [
            'providers' => [

                'EnabledProvider#1' => true,
                'EnabledProvider#2' => 'true',
                'EnabledProvider#3' => 'on',
                'EnabledProvider#4' => 1,

                'DisabledProvider#1' => false,
                'DisabledProvider#2' => 'false',
                'DisabledProvider#3' => 'off',
                'DisabledProvider#4' => 0,

            ],
        ],
    ],
];

Inner Service Manager

In the example above you can see service_manager definition., _(*7)

The module attaches itself to the configuration merge process, thus the application's default ServiceManager is not yet available. In order to keep the service manager's functionality, zf-external-config-module creates its own manager!, _(*8)

Your service can be created by factory, can be declared invokable etc. - the same way you normally declare services., _(*9)

But remember, this service ends its life just after external configuration is loaded and merged!, _(*10)

Passing configuration to your providers

When defining your own providers you might require to pass some credentials or other parameters into the provider instance. To do so - the best way is to use factory functionality, because factories have the (inner) service manager injected!, _(*11)

Inner Service Manager has the application configuration and zf-external-config-module's configuration registered as services:, _(*12)

use Psr\Container\ContainerInterface;
use \RstGroup\ZfExternalConfigModule\Config\ExternalConfigListener;

final class ExampleServiceFactory {
    public function __invoke(ContainerInterface $container) {
        /* getting app's configuration */
        $appConfig = $container->get(
            ExternalConfigListener::SERVICE_APPLICATION_CONFIG
        );

        /* getting zf-external-config-module configuration */
        $moduleConfig = $container->get(
            ExternalConfigListener::SERVICE_EXTERNALS_CONFIG
        );

        (...)
    }
}

Note that the rst_group.external_config key is removed from application's configuration, but you can still get it using module's config., _(*13)

Writing your own provider

External config providers have to implement \RstGroup\ZfExternalConfigModule\Config\ConfigProviderInterface and be registered in module and inner service manager. Those are the only requirements!, _(*14)

You can store the code in your own application's codebase, but we recommend to share it with the community and publish it on GitHub & Composer :) We'll gladly add your provider to this package's suggested providers!, _(*15)