Implemented saving/loading of custom properties on worlds

Custom properties on worlds can only be accessed and modified through
the scripting API at the moment, but since this is possible we better
also save them.

Closes #4025

NEWS.md

@@ -3,6 +3,7 @@
 * Scripting: Added `FileFormat.nameFilter`
 * Scripting: Added `MapEditor.currentBrushChanged` signal
 * Scripting: Added `tiled.cursor` to create mouse cursor values
+* Fixed saving/loading of custom properties set on worlds (#4025)
 * Fixed crash when accessing a world through a symlink (#4042)
 * Fixed error reporting when exporting on the command-line (by Shuhei Nagasawa, #4015)
 

src/libtiled/world.cpp

@@ -311,6 +311,10 @@ std::unique_ptr<World> World::load(const QString &fileName,
             world->patterns.append(pattern);
     }
 
+    const QJsonArray properties = object.value(QLatin1String("properties")).toArray();
+    const ExportContext context(dir.path());
+    world->setProperties(propertiesFromJson(properties, context));
+
     world->onlyShowAdjacentMaps = object.value(QLatin1String("onlyShowAdjacentMaps")).toBool();
 
     if (world->maps.isEmpty() && world->patterns.isEmpty())
@@ -357,11 +361,16 @@ bool World::save(World &world, QString *errorString)
         patterns.append(jsonPattern);
     }
 
+    const ExportContext context(worldDir.path());
+    const QJsonArray properties = propertiesToJson(world.properties(), context);
+
     QJsonObject document;
     if (!maps.isEmpty())
         document.insert(QLatin1String("maps"), maps);
     if (!patterns.isEmpty())
         document.insert(QLatin1String("patterns"), patterns);
+    if (!properties.isEmpty())
+        document.insert(QLatin1String("properties"), properties);
     document.insert(QLatin1String("type"), QLatin1String("world"));
     document.insert(QLatin1String("onlyShowAdjacentMaps"), world.onlyShowAdjacentMaps);