Remove scopes

[mnapoli]

The goal is to simplify the package for the v6. Scopes are useless: I don't see a valid use case for the "prototype" scope, if needed then it should be replaced by an actual factory.

By removing scopes the API would be simpler as well as the internals of PHP-DI.

[bradynpoulsen]

👍

[bradynpoulsen]

@mnapoli I just wanted to verify that I understand the implications of removing these scopes.
If I have an object that should be receiving a new instance of a dependency every time, I would now have to inject a literal Factory object instead and then use that factory to get the new instance? Or am I missing that there is still support for this in the container definitions?

[mnapoli]

@bradynpoulsen that's correct. I'm still on the fence for this. It would bring some simplifications (and perf improvements since they go hand in hand), but I'm afraid it might be a blocker for some applications…

[mnapoli]

Is there anyone using PHP-DI that would be against removing scopes?

If so please explain your use case :)

[holtkamp]

Is there anyone using PHP-DI that would be against removing scopes?

🙋‍♂️

If so please explain your use case :)

Ok, will try to 😉

UseCase: ViewHelpers
In some cases the use of the "prototype" scope makes perfect sense to me: ViewHelpers. These classes are typically used in ViewScripts to generate "often used" HTML (or some other format).

For example, to render a button element in a ViewScript index.phtml, instead of:

<button id="button1" class="btn-success">ClickMe</button>

a Button ViewHelper class could be used. Note: the request to 'button()' is intercepted by the View::__call() which fetches it from the DependencyInjectionContainer...

For example:

echo $this->button()
    ->setId('button1')
    ->addClass('btn-success')
    ->addContent('ClickMe')
    ->render();

//results in: <button id="button1" class="btn-success">ClickMe</button>

When using the default scope of "singleton", one is forced to "reset" the internal state of the ViewHelper. So in this example we need to reset:

• the $id property
• the $attributes property (which is an array)
• the $content property (which is an array)

When we do NOT reset the internal state and re-use the instance of the ViewHelper, the following occurs:

echo $this->button()
    ->setId('button1')
    ->addClass('btn-success')
    ->addContent('ClickMe')
    ->render();

//results in: <button id="button1" class="btn-success">ClickMe</button>

echo $this->button()
    ->setId('button2')
    ->addClass('btn-warning') //classes are separated by a space
    ->addContent('ClickMeToo')
    ->render();

//results in: <button id="button2" class="btn-success btn-warning">ClickMeClickMeToo</button>

The main challenge in resetting an object "completely" is when it is part of an inheritance hierarchy and the parent classes have properties (private/protected) themselves as well. This involves quite some use of the Reflection classes 😨 .

I started using the Prototype scope for such ViewHelpers. With a fresh object instance each time the ViewHelper is acquired, no more resetting of the objects is required!