I m building a Telegram Bot API library in Ktor and I realiz

Question

I m building a Telegram Bot API library in Ktor and I realized there s something I don t understand about Ktor client I m using `kotlinx serialization` for serializing objects and here s my issue The Telegram API supports a lot of Here s an example of one such method The `getFile` method It has one parameter `file id` which is of type `String` These methods can receive their parameters through JSON objects So if I want to send a request to this method I first create a `class` called `GetFileJSONRequest` with ` SerialName ` annotations because in Kotlin the parameter is called `fileId` and in JSON it has to be `file id` And then I send the request like this ```val response HttpResponse = contentType ContentType Application Json setBody GetFileJSONRequest fileId = fileId ``` This whole process with creating classes seems very tedious and I wonder if there s a much better solution to my problem

Andreas Scheja · Answer

you could just do a `setBody mapOf file id to fileId ` instead

Martin Gaens · Answer

Oh yeah Maps Thank you

Martin Gaens · Answer

I ve got a problem with this solution though `Serializing collections of different element types is not yet supported Selected serializers kotlin String ` This is the code leading to the error ``` sendMessage contentType ContentType Application Json setBody mapOf chat id to chatId toString text to text parse mode to parseMode entities to entities map it toDto disable web page preview to disableWebPagePreview disable notification to disableNotification protect content to protectContent reply to message id to replyToMessageId allow sending without reply to allowSendingWithoutReply reply markup to replyMarkup ```

Martin Gaens · Answer

It is very unfortunate but this is as clean as I could get my code for the `sendMessage` method to be ```internal suspend fun sendMessage chatId Int text String parseMode String = null entities List lt MessageEntity gt = null disableWebPagePreview Boolean = null disableNotification Boolean = null protectContent Boolean = null replyToMessageId Int = null allowSendingWithoutReply Boolean = null replyMarkup ReplyMarkup = null Serializable class Request SerialName chat id val chatId Int SerialName text val text String SerialName parse mode val parseMode String = null SerialName entities val entities List lt MessageEntityDto gt = null SerialName disable web page preview val disableWebPagePreview Boolean = null SerialName disable notification val disableNotification Boolean = null SerialName protect content val protectContent Boolean = null SerialName reply to message id val replyToMessageId Int = null SerialName allow sending without reply val allowSendingWithoutReply Boolean = null SerialName reply markup val replyMarkup ReplyMarkup = null <http client post|client post> sendMessage contentType ContentType Application Json setBody Request chatId = chatId text = text parseMode = parseMode entities = entities map it toDto disableWebPagePreview = disableWebPagePreview disableNotification = disableNotification protectContent = protectContent replyToMessageId = replyToMessageId allowSendingWithoutReply = allowSendingWithoutReply replyMarkup = replyMarkup ```

Aleksei Tirman [JB] · Answer

To solve your problem you can use JSON objects arrays and primitives ``` contentType ContentType Application Json setBody JsonObject mapOf fileId to JsonPrimitive 123 text to JsonPrimitive text flag to JsonPrimitive true ```

Martin Gaens · Answer

There s still a problem I have a lot of ` Serializable` classes How do I pass objects of these classes into the map

Aleksei Tirman [JB] · Answer

Unfortunately you can t mix JsonObject JsonPrimitive etc with serializable classes

Martin Gaens · Answer

So what are my options

Andreas Scheja · Answer

If you re only targeting the JVM you could try Jackson instead of `kotlinx serialization` shouldn t have any problems with mixed maps afaik

Martin Gaens · Answer

Yeah okay I can but that s kinda sad cause I really like `kotlinx serialization` Does this mean it is not yet production ready

Andreas Scheja · Answer

I wouldn t say it s not production ready just your specific use case or rather how you prefer to use it isn t covered yet

Martin Gaens · Answer

But am I not falling for the XY problem now Are there any other ways to solve this I just want to send a JSON object containing serializable objects to an API That doesn t seem like something that should be impossible to achieve

Andreas Scheja · Answer

Tried around a bit more there is `Json encodeToJsonElement ` which will turn any serializable thing into a `JsonElement` which you then can pass to the JsonObject ``` kotlinx serialization Serializable class MyObj val myProperty Double runBlocking val response = contentType ContentType Application Json setBody JsonObject mapOf file id to JsonPrimitive 123 name to JsonPrimitive test obj to DefaultJson encodeToJsonElement MyObj 2 0 println response status ```

Martin Gaens · Answer

Awesome thank you very much I ll give it a try in the following hour