WebWork adds support for client-side validation on top of XWork's standard validation framework. You can enable it on a per-form basis by specifying validate="true" in the <ww:form> tag:
<ww:form name="'test'" action="'javascriptValidation'" validate="true"> ... </ww:form>
Of course, all the standard validation configuration steps still apply. Enabling client-side validation will produce (harmless) scripting errors if not configured properly.
Upgrade Alert: To use client-side validation, make sure you have defined the correct validators in validators.xml. You must be using the com.opensymphony.webwork.validators.JavaScriptRequired*Validator version of the standard XWork validators.
Building a Validator that supports client-side validation
Any validator can be extended to support client-side validation by implementing the com.opensymphony.webwork.validators.ScriptValidationAware interface:
public interface ScriptValidationAware extends FieldValidator { public String validationScript(Map parameters); }
The value returned by validationScript will be executed on the client-side before the form is submitted if client-side validation is enabled. For example, the requiredstring validator has the following code:
public String validationScript(Map parameters) { String field = (String) parameters.get("name"); StringBuffer js = new StringBuffer(); js.append("value = form.elements['" + field + "'].value;\n"); js.append("if (value == \"\") {\n"); js.append("\talert('" + getMessage(null) + "');\n"); js.append("\treturn '" + field + "';\n"); js.append("}\n"); js.append("\n"); return js.toString(); }
Only JavaScript is supported at this time.