SelectAction Sample |  |
Using SelectAction
This simple example shows how to dispatch submit events from an HTTP form to handler methods.
Action Class
First, create a subclass of SelectAction:
import net.jspcontrols.dialogs.actions.SelectAction;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletRequest;
import java.util.Map;
import java.util.HashMap;
import java.io.IOException;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForward;
public class SelectActionTest extends SelectAction {
// Define mapping from button to method
protected Map getKeyMethodMap() {
Map map = new HashMap();
map.put(getInitKey()+"-ADD", "add");
map.put(getInitKey()+"-DELETE", "delete");
return map;
}
// Handler of Add button
public ActionForward add(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
System.out.println("--> add");
return mapping.findForward("addpage");
}
// Handler of Delete button
public ActionForward delete(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
System.out.println("--> delete");
return mapping.findForward("deletepage");
}
// Handler of unknown button, which name does not start with button prefix
public ActionForward unspecified(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
System.out.println("--> unspecified");
return mapping.findForward("unspecifiedpage");
}
}
Notice, that unspecified is called when request does not contain parameters starting with prefix. If a button with a proper prefix is selected, but action class does not have a handler for this button, then exception is thrown instead of calling unspecified method.
Configuration
Here is the action mapping configuration in struts-config.xml file:
<struts-config>
<form-beans>
<!-- Struts requires, that a form bean must be defined for each
action processing POST request. To comply with this rule,
a dynabean is defined here, but it is not used -->
<form-bean name="dummyForm" type="org.apache.struts.action.DynaActionForm"/>
</form-beans>
<action-mappings>
<action path="/selectaction"
type = "acme.SelectActionTest"
name = "dummyForm">
<forward name = "addpage" path="/selectadd.html"/>
<forward name = "deletepage" path="/selectdelete.html"/>
<forward name = "unspecifiedpage" path="/selectunspecified.html"/>
</action>
</action-mappings>
</struts-config>
Web pages
Starting page, selectinput.html:
<html>
<h2>INPUT</h2>
<form action="http://localhost:8080/strutsdialog/selectaction.do" method="post">
<input type="submit" name="DIALOG-EVENT-ADD" value="Add button" /><br><br>
<input type="submit" name="DIALOG-EVENT-DELETE" value="Delete button fancy caption" /><br><br>
<input type="submit" name="DIALOG-EVENT-unknown" value="No corresponding handler (exception)" /><br><br>
<input type="submit" name="some-garbage" value="Does not start with prefix (unspecified)" />
</form>
</html>
Page shown when "Add" button selected, selectadd.html:
<html>
<h2>ADD</h2>
</html>
Page shown when "Delete" button selected, selectdelete.html:
<html>
<h2>DELETE</h2>
</html>
Page shown when unspecified button selected, selectunspecified.html:
<html>
<h2>UNSPECIFIED</h2>
</html>
