Doc: Extend the documentation for the "outer" value

Change-Id: I6fff3d3cc73bd664c29b67239b88c2e09b5d6fe2
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

2 files changed, 17 insertions, 1 deletions

diff --git a/doc/reference/items/language/module.qdoc b/doc/reference/items/language/module.qdoc
index 27b3167a6..8b6c5ca9b 100644
--- a/doc/reference/items/language/module.qdoc
+++ b/doc/reference/items/language/module.qdoc
@@ -131,7 +131,8 @@
 
     \section2 \c outer
     This value is used in nested items, where it refers to the value of the respective property
-    in the surrounding item. It is often encountered in \l{Group Item}{groups}:
+    in the surrounding item. It is only valid in \l{Group Item}{groups} and
+    \l{Properties Item}{Properties items}:
     \code
     Product {
         Depends { name: "mymodule" }
diff --git a/doc/reference/items/language/properties.qdoc b/doc/reference/items/language/properties.qdoc
index 4e2cb345f..d9f601ddb 100644
--- a/doc/reference/items/language/properties.qdoc
+++ b/doc/reference/items/language/properties.qdoc
@@ -89,6 +89,21 @@
     }
     \endcode
 
+    In \c Properties items one can access the \l{Module Item#outer}{outer value} of a property.
+    \code
+    Product {
+        Properties {
+            condition: qbs.targetOS.contains("windows")
+            cpp.defines: outer.concat("ON_WINDOWS")     // === ["FOO", "ON_WINDOWS"]
+        }
+        Properties {
+            condition: qbs.targetOS.contains("linux")
+            cpp.defines: ["ON_LINUX"]                   // === ["ON_LINUX"]
+        }
+        cpp.defines: ["FOO"]
+    }
+    \endcode
+
     We suggest to use the \c Properties item for mutually exclusive conditions only. It is
     especially useful if there are several properties to set, based on the same condition.