[Bridge/Symfony/Bundle] configurable asset package

[smatyas]

Description
Using the Symfony framework, it would be useful in some cases if we could configure the "asset package" used by the api platform.
In this way, we would have more control over the generated asset urls: https://symfony.com/doc/4.4/reference/configuration/framework.html#packages

Example
There could be a new config option with the currently used null default value, so it would be backward-compatible.

# app/config/packages/api_platform.yaml
api_platform:
    asset_package: 'custom_package'

The current templates should need only some minor modifications i.e.:

- <link rel="stylesheet" href="{{ asset('bundles/apiplatform/style.css') }}">
+ <link rel="stylesheet" href="{{ asset('bundles/apiplatform/style.css', asset_package) }}">

And of course that new parameter has to be set for the templates i.e. in \ApiPlatform\Core\Bridge\Symfony\Bundle\Action\SwaggerUiAction::getContext

[smatyas]

I'm willing to contribute a PR for this if you find it useful.

[soyuka]

This would be to change the css used by Swagger ui ? I'd just add my own swagger ui using the /docs.json entrypoint given by api platform.

[smatyas]

The opposite! I'd like to keep the default ui, which is totally fine for me.

But if for whatever reason I have to modify the default base_path, that will break the api platform default swagger ui (because that will use the same default setting). Now this is what I'd like to solve using a configurable asset package name.

For example, if I have to use this config, that will break the api platform ui:

# config/packages/framework.yaml
framework:
    # ...
    assets:
        base_path: '/custom_base_path'

With the proposed changes, I believe can confirm that I could use the following assets config to make everything work:

# config/packages/framework.yaml
framework:
    # ...
    assets:
        base_path: '/custom_base_path' # the default
        packages:
            api_platform:
                base_path: '/'

and

# app/config/packages/api_platform.yaml
api_platform:
    asset_package: 'api_platform'

---

Probably any package that uses the asset twig function should have such a configurable option.

[soyuka]

I see, please open a pull request to add this feature (targeting master).