|Apache Struts 2 Documentation > Home > Guides > Core Developers Guide > Validation > Client Side Validation|
The framework adds support for client-side validation on top of the standard validation framework.
Client-side validation can be enabled on a per-form basis by specifying validate="true" in the form tag.
If a name for the form is not given, the action mapping name will be used as the form name. Otherwise, a correct action and namespace attributes must be provided to the <saf:form> tag.
Technically, the form's action attribute can refer to a "path" that includes the namespace and action as a URI. But, client-side validation requires that the action name and namespeact to be set separately.
All the usual validation configuration steps apply to client-side validation. Client-side validation uses the same validation rules as server-side validation. If server-side validation doesn't work, then client-side validation won't work either.
|The left hand doesn't know ...|
The required attribute on many Struts Tags is not integrated with client-side validation! The tag attribute is used by certain themes (like xhtml) to put a visual marker (usually '*') next to the field. The tag doesn't know if the validation system actually "requires" the field or not.
There are two styles of client side validation.