Hey all ! I’m using Ktor in a multiplatform libra...

# ktor

[Melih Aksoy]

Hey all !

I’m using Ktor in a multiplatform library, where I need to post some json body to url.

My current setup for dependencies is

sourceSets {
        commonMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib-common'
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core-common:$coroutine_version"
                implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime-common:$serializer_version"

                implementation "io.ktor:ktor-client-core:$ktor_version"
                implementation "io.ktor:ktor-client-json:$ktor_version"
            }
        }
        androidMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib'
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutine_version"
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutine_version"
                implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime:$serializer_version"

                implementation "io.ktor:ktor-client-android:$ktor_version"
                implementation "io.ktor:ktor-client-json-jvm:$ktor_version"
            }
        }
        iosMain {
            dependencies {
                implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core-native:$coroutine_version"
                implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime-native:$serializer_version"


                implementation "io.ktor:ktor-client-ios:$ktor_version"
                implementation "io.ktor:ktor-client-json-native:$ktor_version"
            }

        }
    }

I’m having trouble with keeping client in common. If I use client in common module as just an HttpClient(), without features, I’m getting class cast exception as in https://github.com/ktorio/ktor/issues/997.

Defining content type does not solve it, but I can add JsonFeature to my client. This ends up crashing in Android tho:

Caused by: java.lang.IllegalStateException: Fail to find serializer. Consider to add one of the following dependencies: 
     - ktor-client-gson
     - ktor-client-json // <- Oh well, it's actually there isn't it ?
     - ktor-client-serialization

As seen above in dependencies, I’m including io.ktor:ktor-client-json in common, but it does not contain any serializer that I can assign in

install(JsonFeature) {
            serializer = ????
}

block. If I define serializer as expect and try to implement actual for Android, it’s fine, but again, I can’t find any for iOS implmentation ( io.ktor:ktor-client-json-native ).

What is the right way to do this by using kotlinx.serialization for both platforms ?

[Dominaezzz]

serializer = KotlinxSerializer()

[Dominaezzz]

You also want implementation("io.ktor:ktor-client-serialization:$ktorVersion")

[Melih Aksoy]

implementation("io.ktor:ktor-client-serialization:$ktorVersion") I’ll try with this one, but should it be a dependency for all three modules or just for common ? I found other examples using serializer = KotlinxSerializer(), but I don’t have KotlinxSerializer class in common.

[Dominaezzz]

Just common is fine.

[Dominaezzz]

You also need implementation("io.ktor:ktor-client-serialization-jvm:$ktorVersion"), etc.

[Melih Aksoy]

And implementation "io.ktor:ktor-client-serialization-native:$ktor_version" for iOS

[Melih Aksoy]

Now it’s all connected and working, thanks a lot !! It’d be great if documentation was mentioning them 😞

[mbonnin]

+1 to that, having to copy/paste various dependencies in all blocks feels like a lot of duplication. Would it be possible to land on a convention like "if artifact-common is a dependency and artifact-jvm exists, then depend on it automatically" ?

[mbonnin]

that would have to be a lot smarter than that of course...

[Dominaezzz]

They have that already for some artefacts. Not sure why it didn't work for this particular one.

[mbonnin]

Is that the gradle metadata thing ?

[Dominaezzz]

Yeah

[mbonnin]

👍