Hi guys:wave: My android project contains three modules: 1. app 2. ui(jetpack compose) 3. sdk(kotlin...

# multiplatform

[Elnur Jeksenov]

Hi guys👋 My android project contains three modules: 1. app 2. ui(jetpack compose) 3. sdk(kotlin multiplatform, ktor client)
So I’m making requests to server in sdk(kotlin multiplatform) module. I want to upload file via multipart-form-data, but there is no support for java.io.file in kotlin multiplatform. Have you got any idea to solve this problem?

[Andrew]

I have not used a lot of the things in this setup but have an idea of how it might work. How would you send some random bytes of data from a byte[] array?

[Andrew]

If that works then there might be some other library to handle files in KMP or you can just write your own file class using expect/actual. I did similar for java.util.date recently.

[Andrew]

Basically each platform needs to do its implementation of file io (via library or you code it) which can abstract it so KMP can use it. ktor client is doing that for the network layer

[Andrew]

https://github.com/Kotlin/kotlinx-io

[Elnur Jeksenov]

I didn’t get your question. I have tried to use this library, there is no files support. It’s unavailable yet.

[Elnur Jeksenov]

Please, can you show your code or sample?
https://kotlinlang.slack.com/archives/C3PQML5NU/p1605680042077800?thread_ts=1605676676.077300&cid=C3PQML5NU

[Animesh Sahu]

In common create expect class File { /* Bunch of utility ... */ fun abc(): ReturnType }
It behave similar to interface

In JVM do actual typealias File = <http://java.io|java.io>.File

In iOS or something like that do the same

In native use Posix API and create your own File class implementing actual class File {...}

[Elnur Jeksenov]

<http://httpClient.post|httpClient.post>(url) {
            body = MultiPartFormDataContent(
                formData {
                    this.appendInput(
                        key = "first_file_uploaded",
                        headers = Headers.build {
                            append(HttpHeaders.ContentDisposition,
                                "filename=$fileName")
                        }
                    ) {
                        buildPacket { writeFully(byteArray) }
                    }
                }
            )
        }

[Elnur Jeksenov]

kotlinx.serialization.SerializationException: Serializer for class 'MultiPartFormDataContent' is not found.
    Mark the class as @Serializable or provide the serializer explicitly.

[Elnur Jeksenov]

there is exception. Have you got any idea to make ‘MutliPartFormDataContent’ serializable?