A value that identifies the position of the form in the current page, within a sequence forms in series of pages. Typical example is a set of forms that are part of a wizard.

The sequence number is implemented on the Struts platform, with a known attribute of the form bean with name page. Custom navigation rules could be implemented, like the case of Wizard, in which case this variable would be used to decipher what the next page or previous page should be.

To implement this, a hidden variable must be defined on the page.

The page value could be static on the page.

  <html:hidden property="page" value="2"/>
  

Or else, it could be set on the server side.

  <html:hidden property="page"/>
  

Struts validations support this mode of usage, by allowing the specification of for an element on a page, to indicate when its validation becomes active. The validation for the elements on the page would be designated with the page attribute of their validation specification. See the page attribute in the code snippet below.

  <form name="categoryForm">
    <field property="categoryName" depends="required" page="1">
	<arg0 key="categoryForm.categoryName.label"/>
    </field>
  </form>
  

To understand the essence of this, we should recall that the same form bean could be associated with multiple pages. It is possible to configure validation for the different instances by using the page number.

As an alternative, the page or sequence number could be set on the server side. This allows creating logic whereas a page has a full set of elements, but different sub-sets are made visible or enabled based on the page number set on the server side. In other words, the same page could be presented as a series of page, by changing the set of elements that are visible.

The subset could be delineated using the element attribute group-id. For more discussion on this see the element descriptor attributes.