Struggling to deserialize an array of tables

[nellePoint]

EDIT: maybe i should ask rather, how would one go about this initially, ignoring my code below, how would i take in a list of files and their attributes, serialize and then deserialize them

ORIGINAL:

The goal of part of my project is to take the files in a given directory, store some information about them (name, path, size; for example), into toml, then later deserialize that so it can use that information.

im struggling with the deserialization bit of the project.

so to serialize the basic rundown is:

object Index {
    // basic index file configuration
    @Serializable
    data class Main(
        val files: MutableList<Files>,
    )

    @Serializable
    data class Files(
        val file: String,
        val hash: String,
        val metafile: Boolean,
    )
}

fun createOrUpdateIndex(environment: String) {
    val indexArray: MutableList<Index.Files> = ArrayList()

    if (File("index.toml").exists()) {
        File("index.toml").delete()
    }

    File(".").walk().forEach {
        if (it.isFile) {
            val fileName = Path("./").relativize(it.toPath()).toString()
            // hash
            val hash = sha256(it)
            // TODO: check if file is a metafile, and then set to true/false, for now defaults false
            val metafile = false

            indexArray.add(Index.Files(fileName, hash, metafile))
        }
    }

    val serializedIndex =
        Toml.encodeToString(
            serializer(),
            Index.Main(indexArray),
        )

    File("index.toml").bufferedWriter().use { out ->
        out.write(serializedIndex)
    }
}

which leaves me with an index.toml that looks something like:

[[files]]
    file = "testfile.txt"
    hash = "55b2c8e1e83905ceacc27af4d7a5587cd72b4bb04e02df8bb5e7203a9dc67f64"
    metafile = false

[[files]]
    file = "testfile2.txt"
    hash = "b36c51f5b78dd8ffa29c0945f2cba276eefcfde340c9494ce503ac40154447f4"
    metafile = false

then when im trying to deserialize:

fun readIndex() {
    if (File("index.toml").exists()) {
        val index: List<Index.Main> = TomlFileReader.decodeFromFile(serializer(), "index.toml")
        index.forEach {
            println(it)
        }
    } else {
        exitProcess(0)
    }
}

running this last bit of code ends me up with

Exception in thread "main" com.akuleshov7.ktoml.exceptions.MissingRequiredPropertyException: Invalid number of key-value arguments provided in the input for deserialization. Missing required property <0> from class <kotlin.collections.ArrayList> in the input. (In your deserialization class you have declared this field, but it is missing in the input)

i feel like im having a basic misunderstanding of some fundamentals but this error is not really clicking for me on what i need to do.

[BOOMeranGG]

The problem is, you serialize your toml into Index.Main:

val serializedIndex =
        Toml.encodeToString(
            serializer(),
            Index.Main(indexArray),
        )

And then you're trying to deserialize the result to List<Index.Main>.

The correct solution for you is:

fun readIndex() {
    if (File("index.toml").exists()) {
        val index: Index.Main = TomlFileReader.decodeFromFile(serializer(), "index.toml")
        index.files.forEach {
            println(it)
        }
    } else {
        exitProcess(0)
    }
}

[nellePoint]

thanks for the reply! this seems to yield the same result

Exception in thread "main" com.akuleshov7.ktoml.exceptions.MissingRequiredPropertyException: Invalid number of key-value arguments provided in the input for deserialization. Missing required property <0> from class <kotlin.collections.ArrayList> in the input. (In your deserialization class you have declared this field, but it is missing in the input)

[BOOMeranGG]

Decoding of arrays of tables has been supported since 0.7.0. I just reproduced your case in the latest version, and it works

So just update the library version :)

[nellePoint]

oh it just wasnt a feature yet when i first started writing the code, makes sense

ill try this when i get home from work tonight

thanks for the tip