Initial experimental implementation of the validation framework.

src/main/scala/app/ServletBase.scala

@@ -1,11 +1,36 @@
 package app
 
+import org.scalatra._
+import org.scalatra.json._
+import org.json4s._
+import org.json4s.jackson._
+
 /**
  * Provides generic features for ScalatraServlet implementations.
  */
-trait ServletBase {
+abstract class ServletBase extends ScalatraServlet with JacksonJsonSupport {
+  
+  implicit val jsonFormats = DefaultFormats
   
   // TODO get from session
   val LoginUser = System.getProperty("user.name")
+  
+  protected def withValidation(validator: Map[String, String] => ValidationResult, params: Map[String, String])(action: => Any): Any = {
+    validator(params).valid match {
+      case true  => action
+      case false => throw new RuntimeException("Invalid Request") // TODO show error page?
+    }
+  }
+  
+  case class ValidationResult(valid: Boolean, errors: Map[String, String]){
+    def toJSON(): JObject = {
+      JObject(
+        "valid"  -> JBool(valid),
+        "errors" -> JObject(errors.map { case (key, value) =>
+          JField(key, JString(value))
+        }.toList)
+      )
+    }
+  }
 
 }