Add JSONP support to JsonPrinters

2 files changed, 16 insertions, 2 deletions

diff --git a/src/main/scala/cc/spray/json/JsonPrinter.scala b/src/main/scala/cc/spray/json/JsonPrinter.scala
index 6f1b20a..44ee9de 100644
--- a/src/main/scala/cc/spray/json/JsonPrinter.scala
+++ b/src/main/scala/cc/spray/json/JsonPrinter.scala
@@ -24,9 +24,20 @@ import java.lang.StringBuilder
  */
 trait JsonPrinter extends (JsValue => String) {
 
-  def apply(x: JsValue) = {
+  def apply(x: JsValue): String = apply(x, None)
+
+  def apply(x: JsValue, jsonpCallback: String): String = apply(x, Some(jsonpCallback))
+
+  def apply(x: JsValue, jsonpCallback: Option[String]): String = {
     val sb = new StringBuilder
-    print(x, sb)
+    jsonpCallback match {
+      case Some(callback) => {
+        sb.append(callback).append('(')
+        print(x, sb)
+        sb.append(')');
+      }
+      case None => print(x, sb)
+    }
     sb.toString
   }
   
diff --git a/src/test/scala/cc/spray/json/CompactPrinterSpec.scala b/src/test/scala/cc/spray/json/CompactPrinterSpec.scala
index a517cd1..4ca4aac 100644
--- a/src/test/scala/cc/spray/json/CompactPrinterSpec.scala
+++ b/src/test/scala/cc/spray/json/CompactPrinterSpec.scala
@@ -43,6 +43,9 @@ class CompactPrinterSpec extends Specification {
       CompactPrinter(JsArray(JsNull, JsNumber(1.23), JsObject(JsField("key", true))))
               mustEqual """[null,1.23,{"key":true}]"""
     )
+    "properly print a JSON padding (JSONP) if requested" in {
+      CompactPrinter(JsTrue, Some("customCallback")) mustEqual("customCallback(true)")
+    }
   }
   
 }
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