demos/quickstart/protected/pages/Controls/Conditional.page


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

<com:TContent ID="body" >

<h1>TConditional</h1>
<com:DocLink ClassPath="System.Web.UI.WebControls.TConditional" />

<p class="block-content">
<tt>TConditional</tt> displays appropriate content based on the evaluation result
of a PHP expression specified via <tt>Condition</tt>.
If the result is true, it instantiates the template <tt>TrueTemplate</tt>;
otherwise, the template <tt>FalseTemplate</tt> is instantiated.
The PHP expression is evaluated right before the <tt>onInit</tt> stage of the control lifecycle.
</p>

<p class="block-content">
Since <tt>TConditional</tt> evaluates <tt>Condition</tt> at a very early stage, it is recommended
you set <tt>Condition</tt> in template only and the expression should not refer to
objects that are available on or after the <tt>onInit</tt> lifecycle.
</p>

<p>
<tt>TConditional</tt> is very light. It instantiates either <tt>TrueTemplate</tt>
<tt>FalseTemplate</tt>, but never both. And the condition is evaluated only once.
A typical usage of TConditional is shown as following:
</p>

<com:TTextHighlighter Language="prado" CssClass="source">
&lt;com:TConditional Condition="$this->User->IsGuest">
	&lt;prop:TrueTemplate>
		<a href="path/to/login">Login</a>
	&lt;/prop:TrueTemplate>
	&lt;prop:FalseTemplate>
		<a href="path/to/logout">Logout</a>
	&lt;/prop:FalseTemplate>
&lt;/com:TConditional>
</com:TTextHighlighter>

<com:RunBar PagePath="Controls.Samples.TConditional.Home" />

<div class="last-modified">$Id$</div></com:TContent>