Jakarta Struts Cookbook

8.12. Localizing Validation Rules

Problem

You need to specify different validation rules for a specific language or country for certain fields on a form.

Solution

First, define the form validation rules for all form fields within the global formset element in the validation.xml file:

<formset>
    <form name="LocalizedForm">
        <field property="employeeId"
                depends="required">
            <arg key="prompt.employeeId"/>
        </field>
        <field property="hourlyRate"
                depends="required,mask">
            <arg key="prompt.hourlyRate"/>
            <var>
                <var-name>mask</var-name>
                <var-value>^\d+\.\d{2}$</var-value>
            </var>
       </field>
    </form>
</formset>

Then create a new formset element using localization attributes—language, country, and variant—for the specific locale. Within this formset, you can configure locale-specific validation rules for those fields that require special treatment:

<formset language="fr">
    <form name="LocalizedForm">
        <field property="hourlyRate"
                depends="required,mask">
            <arg key="prompt.hourlyRate"/>
            <var>
                <var-name>mask</var-name>
                <var-value>^\d+,\d{2}$</var-value>
            </var>
        </field>
    </form>        
</formset>

Discussion

You can tell the Validator to use specific field validation rules for a particular locale. The formset supports the standard locale properties with these attributes:

• language

• country

• variant

At runtime, the Validator searches the formsets, based on locale, for a matching form definition. It evaluates the locale using the standard search algorithm used for resource bundles; that is, if it can't find its match for the ...