Jakarta > Tapestry
Jakarta
 
Font size:      

If

Conditionally emulates an element and its attributes and/or includes a block of content if a condition is met.

See also: org.apache.tapestry.components.IfBean, Else, Conditional

Parameters

Name Type Direction Required Default Description
condition boolean in yes   The condition to evaluate.
conditionValue boolean in no   The value of the condition. During render this is obtained from the condition parameter. During rewind it is the submitted condition.
listener IActionListener in no   The listener is called before the component renders itself, regardless of the value of the condition parameter.
element String in no   The element to emulate. If specified, then the component acts like an Any, emitting an open and close tag. Informal parameters are applied to the tag. If no element is specified, informal parameters are ignored.
volatile boolean in no false Only active in a form. Determines whether to avoid creating hidden fields within a form. Using this parameter may make the form structure different during render and rewind, and cause exceptions as a result. Please use with caution.

Body: allowed

Informal parameters: allowed

Reserved parameters: name, form

Examples

In this example we say hello to our user if he/she has login, or we ask him/her login.

Home.html

...
<p>
Hello, <span jwcid="@If" condition="ognl:user.login"><span jwcid="@Insert" value="ognl:user.name"/></span>
<span jwcid="@Else">please <span jwcid="@PageLink" page="Login">login</span></span>
</p>
...