DynamicObject: Make virtual functions non-virtual

BREAKING_CHANGES.md

@@ -2,6 +2,40 @@
 
 # Version 8.0.1
 
+## Change
+
+All member functions of DynamicObject other than clone() and writeAsJSON() have
+been made non-virtual.
+
+**Possible Issues**
+
+Classes that override these functions will fail to compile.
+
+**Workaround**
+
+Instead of overriding hasMethod() and invokeMethod(), call setMethod() to
+add new member functions.
+
+Instead of overriding getProperty() to return a custom property, add that
+property using setProperty().
+
+**Rationale**
+
+Allowing the implementations of these functions to be changed may cause derived
+types to accidentally break the invariants of the DynamicObject type.
+Specifically, the results of hasMethod() and hasProperty() must be consistent
+with the result of getProperties(). Additiionally, calling getProperty() should
+return the same var as fetching the property through getProperties(), and
+calling invokeMethod() should behave the same way as retrieving and invoking a
+NativeFunction via getProperties().
+
+More concretely, the new QuickJS-based Javascript engine requires that all
+methods/properties are declared explicitly, which cannot be mapped to the more
+open-ended invokeMethod() API taking an arbitrary method name. Making
+invokeMethod() non-virtual forces users to add methods with setMethod() instead
+of overriding invokeMethod(), which is more compatible with QuickJS.
+
+
 ## Change
 
 The LowLevelGraphicsPostscriptRenderer has been removed.

modules/juce_core/containers/juce_DynamicObject.h

@@ -62,18 +62,18 @@ class JUCE_API  DynamicObject  : public ReferenceCountedObject
     /** Returns true if the object has a property with this name.
         Note that if the property is actually a method, this will return false.
     */
-    virtual bool hasProperty (const Identifier& propertyName) const;
+    bool hasProperty (const Identifier& propertyName) const;
 
     /** Returns a named property.
         This returns var() if no such property exists.
     */
-    virtual const var& getProperty (const Identifier& propertyName) const;
+    const var& getProperty (const Identifier& propertyName) const;
 
     /** Sets a named property. */
-    virtual void setProperty (const Identifier& propertyName, const var& newValue);
+    void setProperty (const Identifier& propertyName, const var& newValue);
 
     /** Removes a named property. */
-    virtual void removeProperty (const Identifier& propertyName);
+    void removeProperty (const Identifier& propertyName);
 
     //==============================================================================
     /** Checks whether this object has the specified method.
@@ -82,7 +82,7 @@ class JUCE_API  DynamicObject  : public ReferenceCountedObject
         with this name that's actually a method, but this can be overridden for
         building objects with dynamic invocation.
     */
-    virtual bool hasMethod (const Identifier& methodName) const;
+    bool hasMethod (const Identifier& methodName) const;
 
     /** Invokes a named method on this object.
 
@@ -92,8 +92,8 @@ class JUCE_API  DynamicObject  : public ReferenceCountedObject
         This method is virtual to allow more dynamic invocation to used for objects
         where the methods may not already be set as properties.
     */
-    virtual var invokeMethod (Identifier methodName,
-                              const var::NativeFunctionArgs& args);
+    var invokeMethod (Identifier methodName,
+                      const var::NativeFunctionArgs& args);
 
     /** Adds a method to the class.