Question

Its normal when i use a DoubleBox in a Editor to edit a double property (RequestFactoryEditorDriver)
if i clear the value of the box i get a null pointer exception?

If so how can i validate a DoubleBox with the JSR 303 Validation?

My code looks something like this:

 @DecimalMin(value="0.0", message="decimalMin:0.0", groups = {ImpuestoGroup.class,    ImpuestoIepsGroup.class})
  public double getTasaImpuesto();

 <g:DoubleBox ui:field="tasaImpuesto"></g:DoubleBox>
 @UiField DoubleBox tasaImpuesto;

When i call the driver.flush() need to check the constraints i have this results:

if i put a value diferent than number i get the on the List the bad value
if i put a lower than 0.0 value i can set the constraints to the EditorDriver with driver.setConstraintViolations(constraints);

When i leave blank the field i expect a List with a bad value or the constraint but not a null pointer exception.

The line i get my atention is this one:

 Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError) : Cannot read property 'value_0' of null
at Unknown.$doubleValue(http://localhost:9876/proj/C6E66C9FC3DCB1FC08DFFFC07FE049E0.cache.js@21:38447)

Seems that DoubleBox cannot handle the null value.

Please help me. Thank you.

Answer 1

Answered on Google Groups, copied here for convenience:

DoubleBox uses DoubleParser. DoubleParser returns null if the value is the empty string, and otherwise uses a NumberFormat, and throws a ParserException if it cannot parse. Your edited object’s property is of type double, not java.lang.Double, so when the field is empty, getValue() returns null, and the Editor framework tries to unbox the null to put it into your double property, hence the NullPointerException. With any illegal value, DoubleParser throws; in that case, the ValueBoxEditor returns the last known value, which explains why it doesn’t throw in that case.

Request for enhancement: http://code.google.com/p/google-web-toolkit/issues/detail?id=7783