Add callable field

[Florian-Merle]

The Callable column aims to offer almost as much flexibility as the Twig column, but without requiring the creation of a template.
You simply need to specify a callable, which allows you to transform the 'data' variable on the fly.

The documentation associated for this PR can be found here Sylius/Stack#228

[diimpp]

To match existing documentation, please add YAML example as well.

[Florian-Merle]

I did not include documentation for the YAML format because I believe it's impossible to define a callback field in this format.

[diimpp]

Feature is not complete then and cannot be merged until YAML support will be dropped.

Here is example on how callback can be implemented with non-php config format.

https://symfony.com/doc/current/reference/constraints/Callback.html#external-callbacks-and-closures

[loic425]

I think we can do it. The repository can be a callback in YAML.

app_book_by_english_authors:
    driver:
        name: doctrine/orm
        options:
            class: App\Entity\Book
            repository:
                method: [expr:service('app.english_books_query_builder'), create]

[Florian-Merle]

I reworked the feature and introduced a new way to define callbacks, inspired by Loic's comment:

sylius_grid:
    grids:
        app_user:
            fields:
                name:
                    type: callback
                    options:
                        callback: "callback:strtoupper"
                    label: app.ui.name

This approach allows string callables to be defined directly in YAML.
When configuring grids using PHP, both string and array callables are supported.
When configuring grids using service definitions, everything is supported: string callables, array callables, and closures.

I’ve documented this change here: SyliusGridBundle PR #321.

To implement this, I copied the OptionParser class from the ResourceBundle, slimming it down to only what’s necessary for this feature (handling callbacks). See the original class: OptionsParser in ResourceBundle.

Since the resource bundle is not a required dependencie, I think this is fine to copy the class. However having two OptionParser might not be ideal. Please let me know what you think about it.

[Florian-Merle]

After some thinking, I believe it would be more appropriate to rename CallbackField into CallableField. I'll refactor that. -> this has been done

[diimpp]

@Florian-Merle 👍

[GSadee]

Thank you @Florian-Merle! 🎉