relevant

XForms: binding to an optional element

I asked this on the XSLTForms list, but it’s worth casting a wider net.
Say I have an XML instance like this:
<root>
<format>xml</format>
</root>
Possible values for the format element are “xml”, “text”, “binary”, or a default setting, indicated by a complete absence of the <format> element. I’d like this to attach to a select1 with four choices:
<xf:select1 ref=”format”>…
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