ktor plugins: require configuration values-CodePudding

I was wondering if there is a way to require configuration parameters when making custom plugins? My current hack around is to catch it at runtime

class PluginConfiguration {
    var someConfig: String? = null
}

val MyPlugin =
    createApplicationPlugin(name = "MyPlugin", createConfiguration = ::PluginConfiguration) {
        val someConfig = pluginConfig.someConfig
        pluginConfig.apply {
            if (someConfig == null) { // catch here
                throw java.lang.Exception("Must pass in someConfig")
            }
            onCallReceive { call ->
                // do stuff
            }
        }
    }

but it would be nice if there was a way for the compiler to catch.

My use case for not wanting defaults is that I want to pass in expensive objects that are managed with dependency injection

CodePudding user response：

I think it's not possible with PluginConfiguration API.

But there should be no problem in converting MyPlugin to a function, which will require a parameter to be specified:

fun MyPlugin(someRequiredConfig: String) =
    createApplicationPlugin(name = "MyPlugin", createConfiguration = ::PluginConfiguration) {
        val someConfig = someRequiredConfig
        pluginConfig.apply {
            onCallReceive { call ->
                // do stuff
            }
        }
    }
// ...
install(MyPlugin("config"))