Jakarta Struts Cookbook

5.2. Setting DynaActionForm Initial Values

Problem

You need to initialize the properties in a dynamic action form declared in the struts-config.xml file.

Solution

Specify an initial value for a property of a DynaActionForm using the initial attribute of the form-property element.

<form-bean name="MyForm" type="org.apache.struts.action.DynaActionForm">
  <form-property name="firstName" type="java.lang.String"
              initial="George"/>
  <form-property name="lastName" type="java.lang.String"
              initial="Burdell"/>
  <form-property name="javaCoder" type="java.lang.Boolean"
              initial="true"/>
  <form-property name="friend" type="java.lang.String[]"
                 size="3" 
              initial="Larry,Moe,Curly"/>
</form-bean>

Discussion

DynaActionForms simplify your life as a Struts developer. There is no Java code to write, and when requirements change and you must add fields to a form, you need only change some XML and the Actions that use the form. When working with these forms, a common question that comes up is how to populate the form with initial values. The Solution shows how this can be done using the initial attribute of the form-property element. This attribute specifies a default value for a property. The property is set to this value when the form is created or when the initialize( ) method is called on the form. The time of creation depends on the scope of the form. If the scope is "request," a new form is created for each new request that uses the form. For session scope, the form is created when it can't be found in the ...