runelite-api: expose item composition placeholder ids

runelite-api/src/main/java/net/runelite/api/ItemComposition.java

@@ -58,6 +58,23 @@ public interface ItemComposition
 	 */
 	int getLinkedNoteId();
 
+	/**
+	 * Returns the item ID of the normal/placeholder counterpart. For example, if
+	 * you call this on a monkfish(ID 7946), this method will
+	 * return the ID of a placeholder monkfish(ID 17065), and vice versa.
+	 *
+	 * @return the ID that is linked to this item in normal/placeholder form.
+	 */
+	int getPlaceholderId();
+
+	/**
+	 * Returns a result that depends on whether the item is in placeholder form or
+	 * not.
+	 *
+	 * @return 14401 if placeholder, -1 if normal
+	 */
+	int getPlaceholderTemplateId();
+
 	/**
 	 * Returns the store price of the item. Even if the item cannot be found
 	 * in a store, all items have a store price from which the High and Low

runescape-api/src/main/java/net/runelite/rs/api/RSItemComposition.java

@@ -50,6 +50,14 @@ public interface RSItemComposition extends ItemComposition
 	@Override
 	int getLinkedNoteId();
 
+	@Import("placeholderId")
+	@Override
+	int getPlaceholderId();
+
+	@Import("placeholderTemplateId")
+	@Override
+	int getPlaceholderTemplateId();
+
 	@Import("price")
 	@Override
 	int getPrice();