HelperNotHelper

This article should be checked for accuracy and conformity to style.

It's important to figure out the difference beween class implementing component when you use or not an helper.

Class without Helper

Here is the C++ code

class MyCounterImpl : public XCountable, public XServiceInfo
{
	sal_Int32 m_nRefCount;
	sal_Int32 m_nCount;	
public:
	MyCounterImpl( const Reference< XMultiServiceFactory > & xServiceManager );
	~MyCounterImpl();
 
// XInterface implementation
	virtual void SAL_CALL acquire() throw ();
	virtual void SAL_CALL release() throw ();
	virtual Any SAL_CALL queryInterface( const Type & rType ) throw (RuntimeException);
 
// XServiceInfo	implementation
    virtual OUString SAL_CALL getImplementationName(  ) throw(RuntimeException);
    virtual sal_Bool SAL_CALL supportsService( const OUString& ServiceName ) throw(RuntimeException);
    virtual Sequence< OUString > SAL_CALL getSupportedServiceNames(  ) throw(RuntimeException);
    static Sequence< OUString > SAL_CALL getSupportedServiceNames_Static(  );
 
// XCountable implementation
	virtual sal_Int32 SAL_CALL getCount() throw (RuntimeException);
	virtual void SAL_CALL setCount( sal_Int32 nCount ) throw (RuntimeException);
	virtual sal_Int32 SAL_CALL increment() throw (RuntimeException);
	virtual sal_Int32 SAL_CALL decrement() throw (RuntimeException);
};

As you can see, the class "MyCounterImpl" is derived from XCountable and XServiceInfo, but also from XInterface even if not shown in inheritance part.

Class with an Helper

Here is the code

class MyCounterImpl : public ::cppu::WeakImplHelper2< XCountable, XServiceInfo >
{
	// to obtain other services if needed
	Reference< XMultiServiceFactory > m_xServiceManager;
	sal_Int32 m_nRefCount;
	sal_Int32 m_nCount;
 
public:
// XServiceInfo	implementation
    virtual OUString SAL_CALL getImplementationName(  ) throw(RuntimeException);
    virtual sal_Bool SAL_CALL supportsService( const OUString& ServiceName ) throw(RuntimeException);
    virtual Sequence< OUString > SAL_CALL getSupportedServiceNames(  ) throw(RuntimeException);
    static Sequence< OUString > SAL_CALL getSupportedServiceNames_Static(  );
 
// XCountable implementation
	virtual sal_Int32 SAL_CALL getCount() throw (RuntimeException);
	virtual void SAL_CALL setCount( sal_Int32 nCount ) throw (RuntimeException);
	virtual sal_Int32 SAL_CALL increment() throw (RuntimeException);
	virtual sal_Int32 SAL_CALL decrement() throw (RuntimeException);
};

Go back to Constructing Components.