enable isEmpty and empty methods

Author: celadari

build.sbt

@@ -4,7 +4,7 @@ organization := "com.github.celadari"
 
 homepage := Some(url("https://github.com/celadari/json-logic-scala"))
 
-version := "1.0.0"
+version := "1.1.0"
 
 scalaVersion := "2.10.7"
 
@@ -33,6 +33,8 @@ publishTo := {
   else Some("releases" at "https://oss.sonatype.org/service/local/staging/deploy/maven2")
 }
 
+publishConfiguration := publishConfiguration.value.withOverwrite(true)
+
 credentials += Credentials(Path.userHome / ".sbt" / ".credentials")
 
 publishArtifact in Test := false

project/plugins.sbt

@@ -1,5 +1,7 @@
 resolvers += "jgit-repo" at "https://download.eclipse.org/jgit/maven"
 
-addSbtPlugin("com.typesafe.sbt" % "sbt-ghpages" % "latest.integration")  // https://github.com/sbt/sbt-ghpages
+addSbtPlugin("com.typesafe.sbt" % "sbt-ghpages" % "0.6.3")  // https://github.com/sbt/sbt-ghpages
 
-addSbtPlugin("com.jsuereth" % "sbt-pgp" % "latest.integration")
+addSbtPlugin("com.jsuereth" % "sbt-pgp" % "2.0")
+
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.6")

src/main/scala/com/github/celadari/jsonlogicscala/core/ComposeLogic.scala

@@ -26,14 +26,20 @@ object ComposeLogic {
   }
   val OPERATORS: Array[String] = BINARY_OPERATORS.ALL ++ MULTIPLE_OPERATORS.ALL
 
+  /**
+   * Returns an empty condition.
+   * @since 1.1.0
+   * @return [[ComposeLogic]] instance.
+   */
+  def empty: ComposeLogic = new ComposeLogic("", Array())
+
   private[core] def decode(jsonLogic: JsObject, jsonLogicData: JsObject)(implicit decoder: Decoder): ComposeLogic = {
     // check for operator field
     val fields = jsonLogic.fields
 
     // check for compose logic operator field
     if (fields.length > 1) throw new Error("JSON object is supposed to have only one operator field.")
     val operator = fields.head._1
-    if (!OPERATORS.contains(operator)) throw new Error(s"Invalid parsed operator: $operator")
 
     // if operator is compose logic
     ComposeLogic(operator, decodeArrayOfConditions((jsonLogic \ operator).get, jsonLogicData)(decoder))
@@ -67,4 +73,12 @@ object ComposeLogic {
 
 }
 
-case class ComposeLogic(override val operator: String, conditions: Array[JsonLogicCore]) extends JsonLogicCore(operator)
+case class ComposeLogic(override val operator: String, conditions: Array[JsonLogicCore]) extends JsonLogicCore(operator) {
+
+  /**
+   * Indicates if this represents an empty condition.
+   * @since 1.1.0
+   * @return boolean to indicate if all sub-conditions are empty as well or if sub-conditions array is empty.
+   */
+  def isEmpty: Boolean = conditions.forall(_.isEmpty)
+}

src/main/scala/com/github/celadari/jsonlogicscala/core/Decoder.scala

@@ -28,6 +28,6 @@ abstract class Decoder {
       case "boolean" => jsValue.as[Boolean]
       case otherType => customDecode(jsValue, otherType)(reads)
     }
-    ValueLogic("var", value)
+    ValueLogic("var", Some(value))
   }
 }

src/main/scala/com/github/celadari/jsonlogicscala/core/Encoder.scala

@@ -13,6 +13,8 @@ abstract class Encoder {
   def customValueAndType(value: Any): (String, JsValue)
 
   def getJsValueAndType(value: Any): (String, JsValue) = {
+    if (Option(value).isEmpty) return ("null", JsNull)
+
     value match {
       case value: String => ("string", JsString(value))
       case value: Byte => ("byte", JsNumber(value.toInt))
@@ -36,7 +38,7 @@ abstract class Encoder {
   def encode(valueLogic: ValueLogic[_]): (String, String, JsValue) = {
     val codenameData = valueLogic.codename
 
-    val (typeData, jsValue) = getJsValueAndType(valueLogic.value)
+    val (typeData, jsValue) = getJsValueAndType(valueLogic.valueOpt.orNull)
     (typeData, codenameData, jsValue)
   }
 }

src/main/scala/com/github/celadari/jsonlogicscala/core/JsonLogicCore.scala

@@ -5,6 +5,16 @@ import play.api.libs.json._
 
 object JsonLogicCore {
 
+  /**
+   * Returns an empty condition.
+   * @since 1.1.0
+   * @return [[JsonLogicCore]] instance.
+   * @note Be careful with this method: returned instance is neither of type [[ComposeLogic]] or type [[ValueLogic]].
+   */
+  def empty: JsonLogicCore = new JsonLogicCore("") {
+    override def isEmpty: Boolean = true
+  }
+
   private[core] def decode(jsonLogic: JsObject, jsonLogicData: JsObject)(implicit decoder: Decoder): JsonLogicCore = {
     // check for operator field
     val fields = jsonLogic.fields
@@ -14,8 +24,6 @@ object JsonLogicCore {
 
     // check for compose logic operator field
     if (fields.length > 1) throw new Error("JSON object is supposed to have only one operator field.")
-    val operator = fields.head._1
-    if (!ComposeLogic.OPERATORS.contains(operator)) throw new Error(s"Invalid parsed operator: $operator")
 
     // if operator is compose logic
     ComposeLogic.decode(jsonLogic, jsonLogicData)(decoder)
@@ -60,4 +68,12 @@ abstract class JsonLogicCore(val operator: String) {
   def reduce(implicit reducer: ReduceLogic): Any = {
     reducer.reduce(this)
   }
+
+  /**
+   * Indicates if this represents an empty condition.
+   * @since 1.1.0
+   * @return boolean to indicate if empty.
+   * @since abstract method.
+   */
+  def isEmpty: Boolean
 }

src/main/scala/com/github/celadari/jsonlogicscala/core/ValueLogic.scala

@@ -5,6 +5,13 @@ import play.api.libs.json._
 
 object ValueLogic {
 
+  /**
+   * Returns an empty condition.
+   * @since 1.1.0
+   * @return [[ValueLogic]] instance.
+   */
+  def empty[T]: ValueLogic[T] = new ValueLogic[T]("", None, randomUUID.toString)
+
   private[core] def decode(jsonLogic: JsObject, jsonLogicData: JsObject)(implicit decoder: Decoder): ValueLogic[_] = {
     decoder.decode(jsonLogic, jsonLogicData)
   }
@@ -23,6 +30,14 @@ object ValueLogic {
 
 case class ValueLogic[T](
                           override val operator: String,
-                          value: T,
+                          valueOpt: Option[T],
                           codename: String = randomUUID.toString
-                        ) extends JsonLogicCore(operator)
+                        ) extends JsonLogicCore(operator) {
+
+  /**
+   * Indicates if this represents an empty condition.
+   * @since 1.1.0
+   * @return boolean to indicate if [[ValueLogic.valueOpt]] is [[None]].
+   */
+  def isEmpty: Boolean = valueOpt.isEmpty
+}

src/main/scala/com/github/celadari/jsonlogicscala/operators/ReduceLogic.scala

@@ -25,7 +25,7 @@ class ReduceLogic(implicit cmpOp: CompareOperator, ctnOp: ContainsOperator, bool
     }
   }
 
-  def reduceValueLogic(condition: ValueLogic[_]): Any = condition.value
+  def reduceValueLogic(condition: ValueLogic[_]): Any = condition.valueOpt.get
 
   def reduce(condition: JsonLogicCore): Any = {
     condition match {