Make launchData(for:) accessible to subclasses of CameraController

[nicolasstefoni]

Describe the problem

As a developer integrating CameraKit into a modular architecture, I need to customize the launchData sent to a lens before it’s launched. However, the method launchData(for:) is declared as private, which prevents me from overriding it in a custom subclass of CameraController.

This restriction makes it impossible to inject custom parameters (e.g. apiVersion) into the lens launch payload, unless I fully reimplement parts of the SDK or rely on unsupported workarounds like method swizzling.

Proposed solution

Please consider changing the visibility of:
private func launchData(for lens: Lens) -> LensLaunchData

To something accessible to subclasses, such as:
open func launchData(for lens: Lens) -> LensLaunchData

This would allow us to subclass CameraController and inject custom launch data while preserving the default behavior.

Why this matters

• It would enable more flexible integration scenarios (e.g. feature flags, A/B testing, backend-driven parameters).
• It avoids needing to resort to unsafe or fragile techniques like method swizzling.
• It respects the spirit of modular and extensible design.

Workaround attempts

I’ve tried:

• Subclassing CameraController: not viable due to private method.
• Wrapping it and trying to inject launch data indirectly: no clear entry point.
• Swizzling: possible, but brittle and discouraged in production apps.

Conclusion

Opening up launchData(for:) would make the SDK significantly more customizable with minimal change.

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Thanks for your consideration!

[apessiansc]

Appreciate the feedback @nicolasstefoni. ReferenceUI is open source. You can copy and alter it. In this particular case, you could make your own CameraController without subclassing the one in ReferenceUI.

But I do get your point about the convenience of having an open and overridable launchData(for:). Will pass it on to the team. Thanks again!