xslt: whats the easiest way to do a negated selection?

Question

Basically what I would like is something like this that finds all nodes where the ID cannot be lookup'ed up ('broken links') :

<xsl:variable name="failedIDLookups" select="//inventory/box[@boxtypeID != //boxtypes/@ID]"/>

But this is not working as expected - I suppose the syntax is wrong, what should be the correct way of doing this ?

Can you share snippet of your input data ? It will make clear idea on what you exactly want to do. — Vebbie, Dec 12 '18 at 09:45
`xsl:key` is the best option and faster in execution as answered by @Martin — Amrendra Kumar, Dec 12 '18 at 09:59
See also https://stackoverflow.com/questions/10534882/how-do-i-specify-not-equals-to-when-comparing-strings-in-an-xslt-xslif — Michael Kay, Dec 12 '18 at 11:47

score 4 · Accepted Answer · answered Dec 12 '18 at 09:57

I suspect you want

<xsl:variable name="failedIDLookups" select="//inventory/box[not(@boxtypeID = //boxtypes/@ID)]"/>

which then could be optimized with a key declaration (as a child of xsl:stylesheet)

<xsl:key name="boxtypes-ref" match="boxtypes" use="@ID"/>

and

<xsl:variable name="failedIDLookups" select="//inventory/box[not(key('boxtypes-ref', @boxtypeID))]"/>

1 Answers1