checkbox-to-rows.xhtml

<xh:html xmlns:xh="http://www.w3.org/1999/xhtml"
      xmlns:xf="http://www.w3.org/2002/xforms"
      xmlns:xxf="http://orbeon.org/oxf/xml/xforms"
      xmlns:ev="http://www.w3.org/2001/xml-events"
      xmlns:xs="http://www.w3.org/2001/XMLSchema"
      xmlns:fr="http://orbeon.org/oxf/xml/form-runner">
    <xh:head>
        <xf:model>
            <xf:instance>
                <instance>
                    <checked/>
                </instance>
            </xf:instance>
        </xf:model>
    </xh:head>
    <xh:body>
        <xf:select appearance="full" ref="checked">
            <xf:item>
                <xf:label>1</xf:label>
                <xf:value>1</xf:value>
            </xf:item>
            <xf:item>
                <xf:label>2</xf:label>
                <xf:value>2</xf:value>
            </xf:item>
            <xf:item>
                <xf:label>3</xf:label>
                <xf:value>3</xf:value>
            </xf:item>
        </xf:select>
        <xf:trigger>
            <xf:label>Add rows</xf:label>
            <xf:action event="DOMActivate" iterate="xxf:split(checked)">
                <xf:var name="current" value="."/>
                <xf:insert context="instance()" origin="xxf:element('row', $current)"/>
            </xf:action>
        </xf:trigger>
        <xh:div style="margin-top: 1em">
            <xf:repeat ref="row">
                <xf:input ref="."/>
            </xf:repeat>
        </xh:div>
    </xh:body>
</xh:html>