Session scope

The session scope

Session scope means that an instance is only created once in a session, and not a new one for each request.

Stubbles IoC is prepared to support the session scope. It doesn't offer an own session scope implementation, but it's very easy to implement one. For this, the stubbles\ioc\binding\BindingScope interface has to be implemented, which only consists of one method:

/**
 * returns the requested instance from the scope
 *
 * @param  \ReflectionClass $impl concrete implementation
 * @param  \stubbles\ioc\InjectionProvider $provider
 * @return Object
 */
public function getInstance(\ReflectionClass $impl, InjectionProvider $provider)

Within this method the implementation has to decide whether there is already an instance of the class denoted by $impl within the session, or if a new instance has to be created. Luckily the creation of the new instance is delegated to $provider. An very simplistic approach to implement the session scope might look like that:

namespace example;
use stubbles\ioc\InjectionProvider;
use stubbles\ioc\binding\BindingScope;

class ExampleSessionScope implements BindingScope
{
    /**
     * returns the requested instance from the scope
     *
     * @param  \ReflectionClass $impl concrete implementation
     * @param  \stubbles\ioc\InjectionProvider $provider
     * @return object
     */
    public function getInstance(\ReflectionClass $impl, InjectionProvider $provider)
    {
        if (!isset($_SESSION[$impl->getName()]) {
            $_SESSION[$impl->getName()] = $provider->get();
        }

        return $_SESSION[$impl->getName()];
    }
}

To make the session scope available add it to the binder instance:

$binder->setSessionScope(new ExampleSessionScope());

Now you can bind classes to the session scope:

$binder->bind('Person')
       ->to('Mikey')
       ->inSession();

Please note that the call to inSession() will throw a stubbles\lang\exception\RuntimeException in case no session scope was added before. This means you can only bind to the session scope after a session scope implementation was added to the binder.