Code for the article: "Uploading a file with progress in Kotlin"

AttachmentUploader.kt

private fun createUploadRequestBody(
    file: File,
    mimeType: String,
    progressEmitter: PublishSubject<Double>
): RequestBody {
    val fileRequestBody = file.asRequestBody(mimeType.toMediaType())
    return CountingRequestBody(fileRequestBody) { bytesWritten, contentLength ->
        val progress = 1.0 * bytesWritten / contentLength
        progressEmitter.onNext(progress)

        if (progress >= 1.0) {
            progressEmitter.onComplete()
        }
    }
}