Showcase short definition syntax

[ogizanagi]

No description provided.

[voronkovich]

@ogizanagi, I think it should be same as null

[ogizanagi]

You're right. ~ means null using yaml.
But actually, configuring null for a service definition does not mean anything, and is converted to an empty array behind the scene.

I felt like adding this comment would help the user to understand the service definition is either the full mapping of definition's attributes ({ attributes: [...], tags: [...], public: false, ... }) or directly the list (or mapping for named arguments) of constructor parameters.

But maybe that's not necessary.

[bocharsky-bw]

I'd prefer to be consistent and use the same syntax in the whole app, i.e.:

    AppBundle\EventListener\CommentNotificationSubscriber:
        $sender: '%app.notifications.email_sender%'

You explain the Yaml syntax here, which is not related to the Symfony Demo I think.

[ogizanagi]

Sure, let's do this. :)

[javiereguiluz]

@ogizanagi thanks for this! I like it ... and I didn't remember this shortcut syntax, so it's great to re-learn it!