Simple fr:tree-select1 example

view.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>
        <xh:title>XForms Hello</xh:title>
        <xh:script type="text/javascript" src="/apps/fr/resources/scalajs/orbeon-form-runner.js"/>
        <xf:model xxf:assets.baseline.excludes="/ops/javascript/scalajs/orbeon-xforms.js">
            <xf:instance>
                <value xmlns=""/>
            </xf:instance>

            <xf:instance id="tree-items">
                <items>
                    <choices>
                        <item label="Item 1" value="1">
                            <item label="Item 1.1" value="1.1">
                                <item label="Item 1.1.1" value="1.1.1">
                                    <item label="Item 1.1.1.1" value="1.1.1.1"/>
                                    <item label="Item 1.1.1.2" value="1.1.1.2"/>
                                </item>
                                <item label="Item 1.1.2" value="1.1.2">
                                    <item label="Item 1.1.2.1" value="1.1.2.1"/>
                                    <item label="Item 1.1.2.2" value="1.1.2.2"/>
                                </item>
                            </item>
                            <item label="Item 1.2" value="1.2">
                                <item label="Item 1.2.1" value="1.2.1">
                                    <item label="Item 1.2.1.1" value="1.2.1.1"/>
                                    <item label="Item 1.2.1.2" value="1.2.1.2"/>
                                </item>
                            </item>
                        </item>
                        <item label="Item 2" value="2">
                            <item label="Item 2.1" value="2.1">
                                <item label="Item 2.1.1" value="2.1.1">
                                    <item label="Item 2.1.1.1" value="2.1.1.1"/>
                                    <item label="Item 2.1.1.2" value="2.1.1.2"/>
                                    <item label="Item 2.1.1.3" value="2.1.1.3"/>
                                </item>
                            </item>
                            <item label="Item 2.2" value="2.2">
                                <item label="Item 2.2.1" value="2.2.1"/>
                                <item label="Item 2.2.2" value="2.2.2"/>
                            </item>
                        </item>
                    </choices>
                </items>
            </xf:instance>
        </xf:model>
    </xh:head>
    <xh:body>
        <xf:select1 xmlns:xxbl="http://orbeon.org/oxf/xml/xbl" id="control-2-control"  ref="instance()" appearance="tree xtree-plus-minus">
            <xf:itemset ref="instance('tree-items')//item">
                <xf:label ref="@label"/>
                <xf:value ref="@value"/>
            </xf:itemset>
        </xf:select1>
    </xh:body>
</xh:html>