Updating the Model
Many developers of traditional JavaScript-based forms are not accustomed to variables automatically updating for them. With XForms, you can easily create a complex system where XForms automatically figures out what cells to update. This is similar to using a spreadsheet. A dependency graph is automatically created for you and the appropriate cells are automatically updated if an input they depend upon changes.
Here is an example program that demonstrates this.
Screen Image
Here is a screen capture of the application:
Note that top grid is actually just unlabeled input cells. Below that is a sample output inside a table. You should be able to change any of the input cells, enter a tab, and see the output and the footer calculations change.
Link to Working XForms Application
Sample Program
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xf="http://www.w3.org/2002/xforms" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:xs="http://www.w3.org/2001/XMLSchema">;
<head>
<title>XForms Spreadsheat like Update</title>
<style type="text/css">
table {
font-family: Arial, Helvetica, sans-serif;
border-collapse: collapse;
}
th {
color: white;
background-color: black;
}
.output tr td {
border: solid black 1px;
padding: 2px;
text-align: center;
}
</style>
<xf:model>
<xf:instance>
<Spreadsheet xmlns="">
<Row>
<A>10</A>
<B>20</B>
<C>30</C>
</Row>
<Row>
<A>40</A>
<B>50</B>
<C>60</C>
</Row>
<Row>
<A>70</A>
<B>80</B>
<C>90</C>
</Row>
<Results>
<sum/>
<avg/>
<min/>
</Results>
</Spreadsheet>
</xf:instance>
<xf:bind nodeset="/Spreadsheet/Results/sum" calculate="sum(/Spreadsheet/Row/A)" type="xs:decimal" />
<xf:bind nodeset="/Spreadsheet/Results/avg" calculate="avg(/Spreadsheet/Row/B)" type="xs:decimal" />
<xf:bind nodeset="/Spreadsheet/Results/min" calculate="min(/Spreadsheet/Row/C)" type="xs:decimal" />
</xf:model>
</head>
<body>
<xf:group ref="/Spreadsheet">
<xf:input ref="Row[1]/A">
<xf:label></xf:label>
</xf:input>
<xf:input ref="Row[1]/B">
<xf:label></xf:label>
</xf:input>
<xf:input ref="Row[1]/C">
<xf:label></xf:label>
</xf:input>
<br/>
<xf:input ref="Row[2]/A">
<xf:label></xf:label>
</xf:input>
<xf:input ref="Row[2]/B">
<xf:label></xf:label>
</xf:input>
<xf:input ref="Row[2]/C">
<xf:label></xf:label>
</xf:input>
<br/>
<xf:input ref="Row[3]/A">
<xf:label></xf:label>
</xf:input>
<xf:input ref="Row[3]/B">
<xf:label></xf:label>
</xf:input>
<xf:input ref="Row[3]/C">
<xf:label></xf:label>
</xf:input>
<table class="output">
<thead>
<tr>
<th>#</th>
<th>A</th>
<th>B</th>
<th>C</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<xf:output value="1" />
</td>
<td>
<xf:output ref="Row[1]/A" />
</td>
<td>
<xf:output ref="Row[1]/B" />
</td>
<td>
<xf:output ref="Row[1]/C" />
</td>
</tr>
<tr>
<td>
<xf:output value="2" />
</td>
<td>
<xf:output ref="Row[2]/A" />
</td>
<td>
<xf:output ref="Row[2]/B" />
</td>
<td>
<xf:output ref="Row[2]/C" />
</td>
</tr>
<tr>
<td>
<xf:output value="3" />
</td>
<td>
<xf:output ref="Row[3]/A" />
</td>
<td>
<xf:output ref="Row[3]/B" />
</td>
<td>
<xf:output ref="Row[3]/C" />
</td>
</tr>
<tr>
<td />
<td>Sum=<xf:output ref="Results/sum" />
</td>
<td>Avg=<xf:output ref="Results/avg" />
</td>
<td>Min=<xf:output ref="Results/min" />
</td>
</tr>
</tbody>
</table>
</xf:group>
</body>
</html>
Discussion
Due to limitations with some of the XForms implementations this example does not use the "repeat" command but just addresses each cell directly by its address.
Suggested Improvements
This example could be a lot simpler if we used the repeat-nodeset statement in a table. This currently does not work with input cells using FormFaces.
Where this page came from
This page was imported from Wikibooks. From “XForms” on Wikibooks, by its contributors, under CC BY-SA 4.0. Changed here: set as a page; navigation and edit links left out; each image under its own licence, credited in its caption.
Nobody has written it yet — it is the source material at a new address, which is why search engines are asked to skip it and why no one earns from it. It is up for grabs: take it on, and it is yours to rewrite and to earn from.
收录于这些专栏XForms
许可协议： CC BY-SA 4.0 · 改编自 en.wikibooks.org
1
0
0
0
留言
