validwhen Example Form

**Examples of the validwhen validator.**

struts-config-validwhen.xml validation-validwhen.xml

Simple validwhen example The Last Name must be entered IF a First Name is present.

First Name

Last Name

Both Fields Example Either both the fields must be present OR both must be absent.

Numeric Compare Example Maximum value must be numeric and greater than the minimum.

Minimum

Maximum

Address Validation example If any one of the address fields is present then Address Line 1, City and State must be present. Address Line 2 is optional.

Address Line 1
Address Line 2
City
Zip Code

Tips on Using the validwhen Validator

Check Out the User Guide.
Greater Than and Less Than (i.e. > and <) can't be used directly in the validation.xml - you need to use > and < instead.
All comparisons must be enclosed in parens
Only two items may be joined with and or or - so that means if you want to test three separate things, you need to use parenthesis (brackets) appropriately - see the address validation above.

Issues When (trying) to Use the validwhen Validator

java.lang.NoClassDefFoundError antlr.TokenStream - validwhen requires antlr.jar - its distributed in the Struts binary distribution in the lib folder along with all the other jars.
JavaScript Validation Not Working - There is no JavaScript validator for validwhen - its server side only
unexpected token: OR Error - tokens and and or should be lower case
Other unexpected token Errors - somethings wrong with the test's value - the expression can't be parsed. You need to check it carefully to make sure its correctly specified.
Its Not Working! - check the logs / console for any exceptions.