resolve #55 with also handling "file type extension" for term request

ChangeLog.md

@@ -1,9 +1,19 @@
 ## change log ##
 
 * 2017-10-11:  3.6.7
-  - toward #55 "any additional mechanisms for format/serialization resolution?"
+  - resolve #55 "any additional mechanisms for format/serialization resolution?"
     - implement "file type extension" for ontology request
-    - TODO implement "file type extension" for term request
+    - implement "file type extension" for term request.
+      Order of precedence to determine desired format:
+        1. 'format' parameter
+        2. "file extension"
+        3. Accept header
+      Note: in contrast to the *ontology request* case, here we immediately try 
+      resolution of the uri excluding the file extension in the case of absent 
+      'format' parameter' and uri with file extension.
+      Part of the reason is that it's a bit tricky to determine whether the 
+      resolution with the file extension is actually successful or not in the sense
+      of the term actually having triples associated or simply being non existing.
 
 * 2017-10-04:  3.6.6
   - for ttl term request, also handle explicit accept header "text/turtle"

src/main/scala/org/mmisw/orr/ont/service/TripleStoreServiceAgRest.scala

@@ -6,7 +6,7 @@ import org.json4s.{DefaultFormats, Formats}
 import org.json4s.native.JsonParser
 import org.mmisw.orr.ont.{Setup, TripleStoreResult}
 import org.mmisw.orr.ont.auth.authUtil
-import org.mmisw.orr.ont.swld.ontUtil
+import org.mmisw.orr.ont.swld.{FileExt, ontUtil}
 import org.mmisw.orr.ont.util.FileUtils
 
 import scala.concurrent.Promise
@@ -369,17 +369,31 @@ with TripleStoreService with Logging {
                       ): Either[Error, TermResponse] = {
 
       formatOpt match {
-        case Some(format) =>
+        // 1. highest precedence for 'format' parameter:
+        case Some(format) ⇒
           format2accept(format) match {
-            case Some((accept, isSelect)) =>
+            case Some((accept, isSelect)) ⇒
               doRequest(uri, accept, isSelect)
-            case None =>
+            case None ⇒
               Left(NoSuchTermFormat(uri, format))
           }
 
-        case None =>
-          val (accept, isSelect) = accept2AcceptAndSelect(acceptHeader)
-          doRequest(uri, accept, isSelect)
+        case None ⇒
+          ontUtil.recognizedFileExtension(uri) match {
+            // 2. then, "file extension" if any:
+            case Some((uri2, FileExt(fileExt))) ⇒
+              format2accept(fileExt) match {
+                case Some((accept, isSelect)) ⇒
+                  doRequest(uri2, accept, isSelect)
+                case None ⇒
+                  Left(NoSuchTermFormat(uri, fileExt))
+              }
+
+            // 3. Accept header:
+            case _ ⇒
+              val (accept, isSelect) = accept2AcceptAndSelect(acceptHeader)
+              doRequest(uri, accept, isSelect)
+          }
       }
     }