GetSubscribedEvents on partially initialized instance.

[hrach]

getting the subscribed events is quite hacky, for example injections are not injected... so, it is impossible to do any logic in there. I see no added value in this, make it static, or create the instance properly, what do you think?

[fprochazka]

It's meant to be static, but I'm not sure we can do that because of Subscriber interface.

I don't see how the instance can be created properly in compile time. The listener might depend on classes that require shitload of dependencies. I would have to fake-compile the entire container to be able to properly create the listener instances.

Any ideas?

[fprochazka]

I suppose we can create the listener "properly", when the constructor has no dependencies or when it depends only on parameters, not services. Any thoughts?

[hrach]

Well, let me clear the need, then it may be more obvious. I have a neo4j services, which store some metadata (and updated them through events). I have it also on my local machine, but not every developer should be forced to have it, since it's just small part of the app. So I would like to add listener somehow conditionaly. This was the first idea (the easiest): to let me inject my ParameterProvider, when I have option for it.

What is the proper solution?

[fprochazka]

You might have a listener that is invoked on connection to database or application init, that adds another listener if needed. You don't have to specify all events in the getSubscribedEvents, you may add them manually.

Might something like this help?

class SomeListener implements Subsriber
{
    public function __construct(EventManager $evm)
    {
        // ...
    }

    public function getSubscribedEvents()
    {
        return ['Neo4js::onConnect'];
    }

    public function onConnect(...)
    {
        // ...
        $this->evm->addEventListener('Neo4js::onMetadataUpdate', [$this, 'onMetadataUpdate']);
    }

    public function onMetadataUpdate(..)
    {
        // ...
    }

Doctrine uses similar mechanism to add listener for onClear in it's hydrator. Because it doesn't have the lazy listeners natively and therefore it adds it only when it's needed.

But I'm not sure I've understood you properly. Možná to bude snadnější česky?

[hrach]

You understood it correcty. The problem is, the connection is needed only when the event occurs.

[hrach]

Well, I solved this by own extension. So, I don't need any features for doing this, but I would force the getSbscribedEvents to be static.

[fprochazka]

I don't consider this a problem. If you provide better solution that will not break BC, I shall consider it.

[hrach]

What? Why should I provide solution for something ,which isn't a problem :P