Examples of ImagePipelineDelegate?

[treitter]

Hi, I've got a custom dataLoader that makes composite images from local resources. I've got a LazyImage I'm using in SwiftUI that uses a custom pipeline that uses the custom dataLoader. Occasionally, I need to modify the behavior of the dataLoader (by changing some simple internal state) without tearing down the SwiftUI View. If I understand correctly, this is the use case for ImagePipelineDelegate.

Are there examples of how to implement a ImagePipelineDelegate (especially for this simple case)? I tried following the code itself but it's not quite clear to me which functions I need to implement and how. Just implementing dataLoader(for:pipeline:) appears to not be sufficient since none of my images render.

Thank you!

[treitter]

With more-careful reading of the code, it seems like the ImagePipelineDelegate is mostly limited to passive reaction to pipeline events (mainly for the purposes of logging and maybe debugging). I think it would be helpful to clarify that in the class documentation.

I managed to solve my problem by exposing my DataLoader so it can be modified between calls to loadImage. It seems to work well enough.

[kean]

ImagePipelineDelegate is a kitchen sink.

The dataLoader(for:pipeline:) method is designed to be used for customizing which loader is used for a given request. The equivalent requests get coalesced, so it's not guaranteed to be called for each request.

I think it would be helpful to clarify that in the class documentation.

That's a good idea. I think it could also be split into separate protocols in the manner of the URLSession delegate because it does serve different purposes. The monitoring part should definitely be split off.

I managed to solve my problem by exposing my DataLoader so it can be modified between calls to loadImage. It seems to work well enough.

That sounds good. I would appreciate it if you could share a bit more details about what the use case was.