Proper way to inject dynamic configuration into configuration array - php

Question

I'm wondering what is the best way to inject dynamic configuration(retrieved from db for instance) into configuration array in Zend Framework 2? In Module.php I have:
public function onBootstrap(MvcEvent $e) {
$eventManager = $e->getApplication()->getEventManager();
$moduleRouteListener = new ModuleRouteListener();
$moduleRouteListener->attach($eventManager);
$eventManager->attach('route', array($this, 'mergeDynamicConfig'));
}
public function mergeDynamicConfig(EventInterface $e) {
$application = $e->getApplication();
$sm = $application->getServiceManager();
$configurationTable = $sm->get('DynamicConfiguration\Model\Table\ConfigurationTable');
$dynamicConfig = $configurationTable->fetchAllConfig();
//Configuration array from db
//Array
//(
// [config] => 'Test1',
// [config2] => 'Test2',
// [config3] => 'Test3',
//)
//What to do here?
//I want to use the configurations above like $sm->get('Config')['dynamic_config']['config3'];
}

Answer 1

There is a section in the documentation that explains how to manipulate the merged configuration using the specific event ModuleEvent::EVENT_MERGE_CONFIG
Zend\ModuleManager\Listener\ConfigListener triggers a special event, Zend\ModuleManager\ModuleEvent::EVENT_MERGE_CONFIG, after merging all configuration, but prior to it being passed to the ServiceManager. By listening to this event, you can inspect the merged configuration and manipulate it.
The problem with this is that the service manager is not available at this point as the listener's event is one of the first events triggered by the module manager at priority 1000).
This means that you cannot execute your query and merge the config prior to the configuration being passed to the service manager, you would need to do so after.
Perhaps I have misunderstood your requirements, however I would approach this differently.
You could replace any calls where you need config $serviceManager->get('config') with $serviceManager->get('MyApplicationConfig'); which would be you own configuration service that uses the merged application config and then adds to it.
For example, you could register this configuration service in module.config.php.
return [
'service_manager' => [
'factories' => [
'MyApplicationConfig' => 'MyApplicationConfig\Factory\MyApplicationConfigFactory',
]
],
];
And create a factory to do the loading of merged module configuration, making any database calls or caching etc.
class MyApplicationConfigFactory implements FactoryInterface
{
public function createService(ServiceLocatorInterface $sm)
{
$config = $sm->get('config');
$dbConfig = $this->getDatabaseConfigAsArray($sm);
return array_replace_recursive($config, $dbConfig);
}
protected function getDatabaseConfigAsArray(ServiceLocatorInterface $sm)
{}
}
You also have the added benefit that the service is lazy loaded.

Answer 2

I would not use this approuch, for a few reasons.
Putting SQL queries in your Module.php means that they will get executed on EVERY request for every user thus making your application slow, very slow.
If your database is compromised all the config will be stolen as well.
Solution would be to move all the config in your config/autoload/my_custom_config.local.php via array with keys. From there you can always load it without making a single database request. It will be way faster and secure, because the file will be outside your root folder and hacking a server is always alot harder than hacking a database.
If you still want to allow users to eit the options you can simply include the file in an action and show it with a foreach for example. To save the information you can do this:
file_put_contents("my_custom_config.local.php", '<?php return ' . var_export($config, true).';');
One other plus is that if you load your config the way discribe above you can also retrive the config like you want via $sm->get('Config')['dynamic_config']['config3']