Hidden Field Component

See Also | Tutorials

You can drag the Hidden Field component  from the Palette's Basic category to the Visual Designer to create a hidden text field. A hidden field is a form field that is not visible, but can be used to pass data to the server as well as to hold data that can be interpreted by Javascript on the page. A typical use of a hidden field is to store session data in the page as an alternative to using the Session bean to store the data. For example, you might use a hidden field to pass the primary key of the current row back to the same  page, instead of saving and restoring it in session scope.

A Hidden Field component is equivalent to the HTML tag <input type='hidden'>. The value of the field is the data the field stores and passes back to the server when the form is submitted.

Since the field is hidden, the component does not appear on the page, but it does appear in the Outline window. You can select the hidden field in the Outline window and right-click it to open its pop-up menu.

After adding a hidden field to a page, you can do a number of things with it:

• Select the component and edit its properties in the Hidden Field Component Properties Window. Some typical properties to edit are:
  • id. The name of the component. In the JSP file, this name is the value of the component's id attribute. In the page bean, this property's value is the name of the HiddenField object.
     
    
  • value. The value that will be sent to the server.
     
    
  
   
  
• Right-click the component in the Outline window and choose one of the following pop-up menu items:
  • Edit processValueChange Event Handler. Opens the Java Editor with the cursor positioned in the component's processValueChange method so you can insert code that executes when the value of this component changes. For example, the user changes the value of another component that is controlling the value of this component.
     
    
  • Bind to Data. Opens a dialog box that enables you to bind the component's value property to a data provider or an object so you can evaluate the component's value when the page is submitted. For more information, see Bind to Data Dialog Box.
     
    
  • Property Bindings. Opens a dialog box that enables you to bind properties of the component in addition to the value property to other objects or properties that supply data for the values of this component's properties.
     
    
  
   
  

See Also

Binding Component Properties

Working With Components

Component Tasks: Quick Reference

Component Web Tutorials

Data Source Web Tutorials

About the Palette

Tutorials

Delving Into Components Tutorial