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XForms/Select and Group
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Motivation
You want to conditionally display a group of elements based on the value selected from a list. This will work similar to a "switch/case" but you can have each view depend on complex XPath expressions that will evaluated to either true or false.
Screen Image
frame|center|Using bind and select1 to conditionally display a group
In the screen image above, the second item is selected. When a different item is selected, the view under the select list changes.
Sample Program
<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>
Discussion
This program is very similar to the example that uses a button to toggle a switch/case but the value is calculated dynamically by any XPath expression. The prior example that uses switch/case/toggle uses an XML Event to make a specific case visible.
References
Dynamic Labels Read Only