changeset 463:c9c6b01e9b4f

Add function for getting the rood audio item from different item types.

--- a/src/app/analysis-item/AnalysisItem.ts	Fri Jun 30 13:59:21 2017 +0100
+++ b/src/app/analysis-item/AnalysisItem.ts	Fri Jun 30 13:59:51 2017 +0100
@@ -56,15 +56,19 @@
     downcast.collected != null;
 }
 
+export function getRootAudioItem(item: Item): RootAudioItem {
+  if (isPendingRootAudioItem(item)) {
+    return item;
+  }
+  if (isPendingAnalysisItem(item)) {
+    return item.parent;
+  }
+  throw new Error('Invalid item.');
+}
+
 // these should probably be actual concrete types with their own getUri methods
 export function getRootUri(item: Item): string {
-  if (isPendingRootAudioItem(item)) {
-    return item.uri;
-  }
-  if (isPendingAnalysisItem(item)) {
-    return item.parent.uri;
-  }
-  throw new Error('Invalid item: No URI property set.');
+  return getRootAudioItem(item).uri;
 }
 
 export function createExtractionRequest(item: AnalysisItem): SimpleRequest {