tapestry-core/src/test/app1/NestedFormFragment.tml

<t:border xmlns:t="http://tapestry.apache.org/schema/tapestry_5_3.xsd"
        >

    <br/>

    <!-- note that since we won't be submitting the form, we can just bind visible parameters to literal values -->
    <t:form>
        <t:formfragment t:id="outerhide" visible="true" class="well">
            <div id="outertext1">Outer Text -- nested in outerhide</div>
            <label class="checkbox">
                <t:checkbox t:id="innertrigger1" value="true" t:mixins="triggerfragment" fragment="innerhide"/>
                Trigger hide/reveal of innerhide
            </label>
            <t:formfragment t:id="innerhide" visible="true">
                <div id="innertext1">Inner Text -- nested in innerhide</div>
            </t:formfragment>
        </t:formfragment>


    </t:form>
</t:border>