public class If extends AbstractConditional
| Name | Type | Flags | Default | Default Prefix |
|---|---|---|---|---|
| else | org. | literal | ||
| An alternate org.apache.tapestry5.Block to render if org.apache.tapestry5.corelib.base.AbstractConditional#test() is false. The default, null, means render nothing in that situation. | ||||
| negate | boolean | prop | ||
| Optional parameter to invert the test. If true, then the body is rendered when the test parameter is false (not true). | ||||
| test | boolean | Required | prop | |
| If true, then the body of the If component is rendered. If false, the body is omitted. | ||||
| then | org. | literal | ||
| The org.apache.tapestry5.Block to render if org.apache.tapestry5.corelib.base.AbstractConditional#test() is true. The default, null, means render the component body in that situation.. | ||||
<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_3.xsd" xmlns:p="tapestry:parameter">
<body>
<h1>Welcome!</h1>
<t:if test="user">
Welcome back, ${user.firstName}
<p:else>
<t:pagelink page="login">Login</t:pagelink> /
<t:pagelink page="register">Register</t:pagelink>
</p:else>
</t:if>
. . .
</html>
Here, the main text is rendered if the user is logged in (the user property will be non-null after the user logs in). Otherwise, links to a login and register page are rendered.
Tapestry has many built in coercions to boolean:
| Constructor and Description |
|---|
If() |
| Modifier and Type | Method and Description |
|---|---|
protected boolean |
test()
Performs the test via the parameters; return true to render the body of the component, false to render the else
block (or nothing).
|
public If()
protected boolean test()
AbstractConditionaltest in class AbstractConditional5.6.4 - Copyright © 2003-2021 The Apache Software Foundation.