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Scripts

With Izanami, scripts can be evaluated to decide if a feature is active or not. You have the choice between 3 languages :

  • javascript
  • scala
  • kotlin

When writing a script, you have access to

  • context: A json object send by the client
  • enabled: A function to call, the feature is enabled
  • disabled: A function to call, the feature is disabled
  • http: An http client that can be used to request an API.

Debugging​

You can debug script in the UI

Click on the run button to test the script, compiling errors will be printed on the right panel.

You can print logs using println in scala or kotlin and console.log in javascript. The logs will be printed on the left panel.

Writing script with javascript​

The http client expose the call method that take two args :

  • options, an object with the following possible attributes
    • url (required): The url to call.
    • method (default get): The http method betwwen get, post, put, delete, option, patch
    • headers : A object with headerName -> Value
    • body : An optional json string
  • callback: A bifunction with failure or success.
function enabled(context, enabled, disabled, http) {
  http.call(
    {
      url: "http://localhost:9000/api/features/feature:with:script/check",
      method: "post",
      headers: {
        "Izanami-Client-Id": "xxxx",
        "Izanami-Client-Secret": "xxxx",
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        user: context.user,
      }),
    },
    function (error, success) {
      if (error) {
        return enabled();
      } else {
        var resp = JSON.parse(success);
        if (resp.active) {
          return enabled();
        } else {
          return disabled();
        }
      }
    }
  );
}

Writing script with scala​

In scala, the http client is the default playframework WSClient and the json value is play json JsValue. You can find more information here :

A example script doing an http call could be

def enabled(context: play.api.libs.json.JsObject,
             enabled: () => Unit,
             disabled: () => Unit,
             http: play.api.libs.ws.WSClient)(implicit ec: ExecutionContext): Unit = {
    import scala.util._

    http.url("http://localhost:9000/api/features/you:can:write:script:with:scala/check")
        .addHttpHeaders(
            "Izanami-Client-Id" -> "xxxx",
            "Izanami-Client-Secret" -> "xxxx"
        )
        .post(context)
        .onComplete {
            case Success(response) =>
                response.status match {
                    case 200 if (response.json \ "active").asOpt[Boolean].contains(true) =>
                        enabled()
                    case other =>
                        println(s"Oups $other")
                        disabled()
                }
            case Failure(e) =>
                println(s"Oups $e")
                disabled()
        }
}

Writing script with kotlin​

In kotlin, the http client is the default playframework java WSClient and the json value is jackson JsonValue. You can find more information here :

A example script doing an http call could be

fun enabled(context: JsonNode, enabled: () -> Unit, disabled: () -> Unit, wsClient: WSClient) {
    wsClient.url("http://localhost:9000/api/features/you:can:write:script:with:kotlin/check")
      .addHeader("Izanami-Client-Id", "xxxx")
      .addHeader("Izanami-Client-Secret", "xxxx")
      .post(context)
      .whenComplete { wsResponse, e ->
    	  if (e != null) {
            disabled()
        } else {
            when (wsResponse.getStatus()) {
              200 -> {
                val jsonBody = wsResponse.asJson()
                if(jsonBody.get("active")?.asBoolean() ?: false) {
                  enabled()
                } else {
                  println("oups: ${jsonBody}")
                  disabled()
                }
              }
              else -> {
                println("oups: ${wsResponse.getStatus()} ${wsResponse.getBody()}")
                disabled()
              }
            }
        }
      }
}