I see that Parameters can be received from the `request`, but I’m trying to build and write them as ...

# ktor

[bdawg.io]

I see that Parameters can be received from the request, but I’m trying to build and write them as a respond

[orangy]

I don’t think there is anything built in, please file an issue on github.

[orangy]

But I think ContentNegotiation extension is quite easy to build. If client is sending Accept: application/x-www-form-urlencoded of course

[bdawg.io]

This is the implementation I’m going to try out 🙂

call.respond(object : OutgoingContent.ByteArrayContent() {
    override val contentType get() = ContentType.Application.FormUrlEncoded

    override fun bytes(): ByteArray =
        mapOf(
            "error" to "invalid_request",
            "error_description" to "client_id was not valid"
        )
            .map { "${it.key}=${it.value}" }
            .joinToString(separator = "&")
            .toByteArray()
})

[orangy]

I think you might need to quote key & value properly

[orangy]

There is a function:

fun List<Pair<String, String?>>.formUrlEncode(): String

[orangy]

Also fun Parameters.formUrlEncode(): String

[orangy]

So, you may use something like body = parametersOf("a", "1").formUrlEncode()

[orangy]

Or rather

parametersOf(
            "error" to "invalid_request",
            "error_description" to "client_id was not valid"
        ).formUrlEncode()

[orangy]

See https://github.com/ktorio/ktor/blob/master/ktor-server/ktor-server-tests/test/io/ktor/tests/server/http/UrlEncodedTest.kt#L89

[bdawg.io]

Much better!

override fun bytes(): ByteArray = parametersOf(
    "error" to listOf("invalid_request"),
    "error_description" to listOf("client_id was not valid")
).formUrlEncode().toByteArray()

[orangy]

Since formUrlEncode returns a String, and String will automatically be sent as bytes, you don’t need custom OutgoingContent

[orangy]

You can just a make a function something like respondUrlEncoded which will have similar signature to parametersOf and encode them

[orangy]

So you will just use

call.respondUrlEncoded(
    "error" to listOf("invalid_request"),
    "error_description" to listOf("client_id was not valid")
)

[bdawg.io]

I kind of like the idea of having that take in a Parameters so it would abstract where they were received from and it doesn’t seem to add much at the call site

call.respondUrlEncoded(parametersOf(
    "error" to listOf("invalid_request"),
    "error_description" to listOf("client_id was not valid")
))

[orangy]

Yep, this works too.