Newbie: Bind Enums to dropdownbox

[warer]

I am trying to bind an enum to a dropdownbox, and i am having trouble finding some documentation on this.

I probably have to use LabeledEnum. The problem is how all this is tied together.
Can anyone point me to some docs or an example.

[jettro]

I take it you mean a java 5 enum?

[warer]

Yes i mean java 5 enums, i didn't know there were enums in the older versions of java.

[jettro]

Me neither, but you could have meant it in a more generic (oops another java 5 term) way. Maybe you have created your own! Well never mind.

Maybe this can help:
An enum has the method values(), this returns an array with all enum values. Then use standard c:foreach library to represent it, something like this:

<select name="${status.expression}">
<option value=""></option>
<c:forEach items="${enumvalues}" var="value">
<option value="${value}">${value}</option>
</c:forEach>
</select>

I know it is not complete, but maybe it gives you a hint.

[warer]

To put those values i need to make them available to the view.
I am using simpleFormController, but it dosen't have a method that is called before the request is delivered to the view.
Should i implement a method of one of its superclasses to allow that?

[jettro]

Use one of the :
protected Map referenceData(HttpServletRequest request, Object command, Errors errors, int page) throws Exception {

methods

[warer]

Not sure how to use the referenceData function.

Tried to register a enumPropertyEditor. Binding that with
overriding initbinder and registering that one to me enum class.
It was never called.

[Colin Yates]

Can you post your code/config please

[warer]

Code for the enum:

public enum Sex {
	male,female
}

public class SexPropertyEditor extends PropertyEditorSupport {
	
	protected final Log logger = LogFactory.getLog(getClass());
private String female = "female";
	private String male = "male";
	private Sex type = null;
	
	@Override
	public String getAsText() {
		logger.debug("getAsText called");
		if(type != null){
			if(type == Sex.female){
				return female;
			}else
			{
				return male;
			}
			
		}
		return null;
	}

	@Override
	public Object getValue() {
		logger.debug("getValue called");
		return type;
	}
	@Override
	public void setAsText(String arg0) throws IllegalArgumentException {
		logger.debug("setAsText called");
		if(arg0.equalsIgnoreCase(male)){
			type = Sex.male;
		}
		else if(arg0.equalsIgnoreCase(female)){
			type = Sex.female;
		} else {
			throw new IllegalArgumentException();
		}
	}
@Override
	public void setValue(Object arg0) {
		logger.debug("setValue called");
		if(((Sex)arg0) == Sex.male ){
			type = Sex.male;
		}else if(((Sex)arg0) == Sex.female){
			type = Sex.female;
		}
	}

The Form Controller:

public class UserForm extends SimpleFormController {
	/** Logger for this class and subclasses * */
	protected final Log logger = LogFactory.getLog(getClass());

	protected IUserManager userManager;

	
	/* (non-Javadoc)
	 * @see org.springframework.web.servlet.mvc.BaseCommandController#initBinder(javax.servlet.http.HttpServletRequest, org.springframework.web.bind.ServletRequestDataBinder)
	 */
	@Override
	protected void initBinder(HttpServletRequest arg0, ServletRequestDataBinder arg1) throws Exception {
		arg1.registerCustomEditor(Sex.class, new SexPropertyEditor());
		super.initBinder(arg0, arg1);
	}

Is this the way to do it?

[Colin Yates]

A couple of points;
- I would call initBinder *before* you do your registration (just a hunch)
- I usually only override getAsText and setAsText
- I would move the toString/fromString behaviour into the enum itself, so your property editor is calling something like Sex.getSex(final String sex) sex.getAsString().
- if the binder is not matching on Sex.class then register it against the name of the property

What does your form look like? I am assuming it has a get/SetSomething which is of type Sex?