I add APNG Decoder, but it doesn't disk caching

[4z7l]

I need to load Apng from web, so I add custom APNG Decoder using this library

I expected Imageloader stores image in disk at least (not memory), but it requests from network every time.

I used the 1.4.0 version of the coil.

// In Activity
binding.imageView1.loadApng("https://apng.onevcat.com/assets/elephant.png")

// extension fuction
inline fun ImageView.loadApng(
    data: Any,
    imageLoader: ImageLoader = context.imageLoader,
    builder: ImageRequest.Builder.() -> Unit = {}
): Disposable {
    val request = ImageRequest.Builder(context)
        .data(data)
        .target(this)
        .decoder(ApngDecoder())
        .listener { request, metadata ->
            Log.d("loadApng", "${metadata.dataSource} ${metadata.memoryCacheKey} ") // add this line to check where the data come from
        }
        .apply(builder)
        .build()
    return imageLoader.enqueue(request)
}

// Apng Decoder
class ApngDecoder : Decoder {
    override suspend fun decode(pool: BitmapPool, source: BufferedSource, size: Size, options: Options): DecodeResult {
        return DecodeResult(
            drawable = ApngDrawable.decode(source.inputStream()),    // this from "line/apng-drawable" library
            isSampled = false
        )
    }

    override fun handles(source: BufferedSource, mimeType: String?): Boolean {
        return true
    }
}

Logcat

D/loadApng: NETWORK null 

How can I fix to force disk caching? Please help me 😭

+)

I've tried to add the code like this, but sometimes it's cached on disk and sometimes not.
Its operation is not perfect.
What happend?

inline fun ImageView.loadApng(
    data: Any,
    imageLoader: ImageLoader = context.imageLoader,
    builder: ImageRequest.Builder.() -> Unit = {}
): Disposable {

    val forDiskCachingRequest = ImageRequest.Builder(context)
        .data(data)
        .build()
    imageLoader.enqueue(forDiskCachingRequest)

    val request = ImageRequest.Builder(context)
        .data(data)
        .target(this)
        .memoryCachePolicy(CachePolicy.DISABLED)
        .decoder(ApngDecoder())
        .apply(builder)
        .build()

    return imageLoader.enqueue(request)
}

[colinrtwhite]

It's likely the cache control header for the image isn't allowing it to be cached in the disk cache. If you control the server, you can ask them to change the cache-control header. Else, you can overwrite it locally using an OkHttp interceptor (you can copy the code from the sample app which does this).