[WICKET-5866] Reconsider generics of IConverterLocator#getConverter()

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 7.0.0
• Fix Version/s: 8.0.0-M2, 7.5.0
• Component/s: wicket
• Assignee: Sven Meier
• Reporter: Sven Meier
• Created: 25/Mar/15 18:18
• Updated: 22/Jul/16 14:27
• Resolved: 21/Jul/16 20:25

Description

IConverterLocator#getConverter() has a generic parameter <C> currently.

It seems to me that this is not very useful: almost all code calling #getConverter() does not care for the type parameter.

From the user perspective it's very common to override Component#getConverter(). With the need for a cast and to suppress the generics warning, providing a custom converter is much too hard currently:

    public <C> IConverter<C> getConverter(Class<C> clazz)
     {
         if (Date.class.isAssignableFrom(clazz))
         {
             @SuppressWarnings("unchecked")
             return (IConverter<C>)new DateConverter();
         }
         else
         {
             return super.getConverter(clazz);
         }
     }

I propose to remove the generics parameter from the method:

    public IConverter<?> getConverter(Class<?> clazz)
     {
         if (Date.class.isAssignableFrom(clazz))
         {
             return new DateConverter();
         }
         else
         {
             return super.getConverter(clazz);
         }
     }