Standart Errai bind doesn't support empty values for numeric types

[arumad]

Errai DataBinder doesn't translate empty textbox values into null values in binded model.
For example, suppose there are bindable class and autobound template

@Bindable

public class ValueHolder {

  private String comment; //get+set

  private BigDecimal amount; //get+set

}

@Templated

public class ValueEditor {

  @Inject

  @AutoBound

  private DataBinder<T> binder;

  @Bound

  @DataField

  private TextArea comment = new TextArea();

  @Bound

  @DataField

  private TextBox amount = new TextBox();

}

It works perfectly fine with numeric values, but cleaning input would not clean model value,
and change in comment input would cause amount to restore previously entered value.

It's caused by NumberFormatException in BigDecimal constructor called from

org.jboss.errai.databinding.client.api.Convert.to(BigDecimal.class, "")

Is it designed to reject empty numeric inputs?

If not, following patch to Convert allows to clean numeric inputs.

public class Convert {

+ private static final HashSet<Class<?>> SUPPORTED_CLASSES = new HashSet<Class<?>>(Arrays.asList(

+ Integer.class, Long.class, Float.class, Double.class, Boolean.class, Date.class, BigDecimal.class, BigInteger.class));

private static final Map<ConverterRegistrationKey, Converter> defaultConverters =

  new HashMap<ConverterRegistrationKey, Converter>();

===

  return o.toString();

  }

  else if (o.getClass().equals(String.class)) {

+ String string = (String) o;

+ if (string.length() == 0 && SUPPORTED_CLASSES.contains(toType)) {

+ return null;

+ }

  if (toType.equals(Integer.class)) {

[csa]

Hi Olexandr,

Yes the built-in converters for BigDecimal and BigInteger didn't handle that case. They do now in the latest 3.0-SNAPSHOTs. If you can't upgrade you can always define your own binding specific converter (@Bound(converter=MyBigDecimalConverter.class)) or register a default converter for that type. Then you don't have to provide it at each binding.

So, you could simply add this to a client package of your app:

@DefaultConverter
public class BigDecimalConverter implements Converter<BigDecimal, String> {

  @Override
  public BigDecimal toModelValue(String widgetValue) {
    return (widgetValue == null || widgetValue.isEmpty()) ? null : new BigDecimal(widgetValue);
  }

  @Override
  public String toWidgetValue(BigDecimal modelValue) {
    return (modelValue == null) ? "" : modelValue.toString();
  }
}

Cheers,

Christian

[arumad]

Thanks.

Why only BigInteger and BigDecimal are made nullable in 3.0-SNAPSHOT?

Empty values for other types would still fail to reach model.

[csa]

I actually thought I did but you're right I didn't. It should be OK now. However, Boolean.parseBoolean("") is OK as it returns false. Everything else should default to null now.

Thanks!