How to display an enum in a dropdown in Wicket

Its often useful to use an enum as the model for a dropdown (or radio group) in Wicket, but not immediately obvious how to handle the display of the values. Lets say I have an enum with three colors:

[sourcecode language=”java”]
enum Color { RED, GREEN, BLUE };
[/sourcecode]

I can hook this up to a dropdown with the following code:

[sourcecode language=”html”]

[/sourcecode]

[sourcecode language=”java”]
enum Color { RED, GREEN, BLUE };
private Color color = Color.GREEN;
add(new DropDownChoice(“color”, new Model(color), Arrays.asList(Color.values())));
[/sourcecode]

However, that would display “RED”, “GREEN”, “BLUE”. I probably don’t want the dropdown to use the default toString() form of my enum declarations, but rather I want it to load translatable texts from property files.

To do this, I can use Wicket’s EnumChoiceRenderer as follows:

[sourcecode language=”html”]

[/sourcecode]

[sourcecode language=”java”]
enum Color { RED, GREEN, BLUE };
private Color color = Color.GREEN;
add(new DropDownChoice(“color”, Arrays.asList(Color.values()), new EnumChoiceRenderer(this)));
[/sourcecode]

[sourcecode language=”java”]
Color.RED=Red
Color.GREEN=Green
Color.BLUE=Blue
[/sourcecode]

Now I get what I wanted – a dropdown displaying “Red”, “Green” and “Blue”.