How to use hidden field to store data model in wicket - wicket

Question

I have a entity, name Product.It have two property is unit (byte) and unitName(String). unit property is mapped on database. Ex: 0:Kg ; 1:g;.... I want when input a valid unit, unit property is stored; unless, it save to unitName
Product
public class Product implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "product_id")
private int productId;
#Column(name = "product_name")
private String productName;
#Column(name = "unit")
private Byte unit;
#Transient
private String unitName;
}
In unit text field, I use a UnitConvert
UnitConvert
public class UnitConverter implements IConverter<Byte> {
private static final long serialVersionUID = 4798262219257031818L;
public UnitConverter() {
}
#Override
public Byte convertToObject(String value, Locale locale) {
return Text.isEmpty(value) ? 0 : UtilCommon.getTaniCode(value);
}
#Override
public String convertToString(Byte value, Locale locale) {
return (value == null || value==0 ) ? "" : UtilCommon.getTaniName(value);
}
}
I only think about HiddenField to do that, but I don't know how to do that.
Someone know how to use or anything can help me. Thank you very much

Answer 1

So from what I understood you want to save the input of a Model to a different database property depending on certain checks before hand. You can do that in your Form.onSubmit() method.
A very simple implementation could look like this:
public ProductPanel(String id, final IModel<Object> productModel) {
super(id, productModel);
// we're putting the productModel into the constructor.
// Therefore it's guaranteed to be detached
// -> it's okay to have it with final modifier.
IModel<String> formModel = Model.of("");
Form<String> form = new Form<String>("form", formModel) {
#Override
protected void onSubmit() {
super.onSubmit();
String productName = getModelObject();
Object realProduct = productModel.getObject();
if (isAcceptableUnit(productName)) {
realProduct.setUnit(parseUnit(productName));
} else {
realProduct.setUnitName(productName);
}
layer.saveProduct();
}
};
add(form);
TextField<String> productName = new TextField<String>("textField", formModel);
form.add(productName);
}
private boolean isAcceptableUnit(String productName) {
// your logic to determine if it's okay to cast to byte here...
return true;
}
private byte parseUnit(String productName) {
// your logic to parse the String to byte here...
return 0;
}
Some additional comments since I'm uncertain if the code snippets you provided are just for simplicity or actually code pieces:
You should try to avoid declaring your db object Serializable. Should you use normal Model objects to save your DTOs wicket will actually serialize them and you won't be able to do anything with them (well with hibernate at least).
Database object should use LoadableDetachableModel and save the primary key to load the entity in the load() method of it.
This would enable you now to work directly on those objects by using CompoundPropertyModel etc (which has it's pros and cons which I will not explain in detail here).
Still in your case I would add an Model<String> to the form and let the server decide how the input should be handled and mapped to the actual domain object.