XForms/选择和分组
< XForms
您希望根据从列表中选择的值有条件地显示一组元素。这将与“switch/case”类似，但您可以使每个视图依赖于复杂的 XPath 表达式，这些表达式将被评估为真或假。
在上面的屏幕图像中，选择了第二个项目。当选择不同的项目时，选择列表下的视图会发生变化。
<html
xmlns="http://www.w3.org/1999/xhtml"
xmlns:xf="http://www.w3.org/2002/xforms">
<head>
<title>Dynamically bind to a group</title>
<!-- Using bind and relevant in the model to conditionally display a group -->
<!-- Alternative to switch/case/toggle when the id of toggle is dynamically calculated -->
<style type="text/css">
@namespace xf url("http://www.w3.org/2002/xforms");
xf|group {
border: solid black 2px;
background-color: silver;
height: 100px;
}
xf|group xf|label {
position: relative;
font-family: Helvetica, sans-serif;
font-weight: bold;
background-color: white;
padding: 2px;
top: -10px;
left: 10px;
}
xf|group p {
position: relative;
top: -30px;
padding: 5px;
}
</style>
<xf:model>
<xf:instance>
<data xmlns="">
<current-view>one</current-view>
<view-1>one</view-1>
<view-2>two</view-2>
<view-3>three</view-3>
</data>
</xf:instance>
<!-- if the current-view is 'one' make the view-1 group relevent (visible)-->
<xf:bind nodeset="view-1" relevant="../current-view = 'one'" />
<xf:bind nodeset="view-2" relevant="../current-view = 'two'" />
<xf:bind nodeset="view-3" relevant="../current-view = 'three'" />
</xf:model>
</head>
<body>
<xf:select1 ref="current-view">
<xf:label>Select View: </xf:label>
<xf:item>
<xf:label>One</xf:label>
<xf:value>one</xf:value>
</xf:item>
<xf:item>
<xf:label>Two</xf:label>
<xf:value>two</xf:value>
</xf:item>
<xf:item>
<xf:label>Three</xf:label>
<xf:value>three</xf:value>
</xf:item>
</xf:select1>
<br/>
<!-- only one of the three outputs will display -->
<xf:output ref="view-1">
<xf:label>Current view: </xf:label>
</xf:output>
<xf:output ref="view-2">
<xf:label>Current view: </xf:label>
</xf:output>
<xf:output ref="view-3">
<xf:label>Current view: </xf:label>
</xf:output>
<br/>
<br/>
<!-- only a single group will be displayed at any time -->
<xf:group ref="view-1">
<xf:label>View One</xf:label>
<p>One One One One One One One One One One One One One One One One One One</p>
</xf:group>
<xf:group ref="view-2">
<xf:label>View Two</xf:label>
<p>Two Two Two Two Two Two Two Two Two Two Two Two Two Two Two Two Two</p>
</xf:group>
<xf:group ref="view-3">
<xf:label>View Three</xf:label>
<p>Three Three Three Three Three Three Three Three Three Three Three Three Three Three Three Three Three</p>
</xf:group>
</body>
</html>
此程序与使用按钮切换 switch/case 的示例非常相似，但该值是通过任何 XPath 表达式动态计算的。使用 switch/case/toggle 的先前示例使用 XML 事件来使特定情况可见。