Re: [xsl] with XPath 1.0, select all following sibling elements of name "foo" up to the first non-"foo" element

["G. Ken Holman g.ken.holman@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Just eyeballing this, Dmitry, I'm not convinced
it would work if Wolfhart was sitting at a <foo>
at the time he made his request, in which case
the <foo> he was at would incorrectly be included.

Granted the original requirement is
underspecified in this regard, so perhaps my
observation is irrelevant. I'm not trying to
nit-pick but I discounted the use of keys because
of the arbitrary starting point for evaluation.

Also the use= needs a "[1]" predicate to ensure
the correct cardinality for generate-id() in the
general case where there are multiple following siblings that are not <foo>.

I'm usually successful with keys when not having
to deal with the current context.

Wolfhart, am I being too pedantic here?

. . . . . . Ken

At 2021-02-19 01:29 +0000, Dimitre Novatchev dnovatchev@xxxxxxxxx wrote:
> Here is a short and efficient XSLT 1.0 solution using keys:
>
> <xsl:stylesheet version="1.0"
> xmlns:xsl="<http://www.w3.org/1999/XSL/Transform>http://www.w3.org/1999/XSL/
Transform">
> B <xsl:output omit-xml-declaration="yes" indent="yes"/>
> B <xsl:key name="kPrecedingFoo" match="foo"
> use="generate-id(following-sibling::*[not(self::foo)])"/>
> B
> B  <xsl:template match="/*/*[1]">
> B  B  <xsl:copy-of select="key('kPrecedingFoo',
> generate-id(../*[not(self::foo)][1]))"/>
> B  </xsl:template>
> </xsl:stylesheet>
>
> Applying this transformation on variations of
> the following XML document (try uncommenting
> different subsets of the commented elements) produces always the wanted
result:
> <t>
> B  <!-- <bar/> -->
> B  <foo ind="1"/>
> B  <foo ind="2"/>
> B  <!-- <bar/> -->
> B  <foo ind="3"/>
> </t>
>
> Cheers,
> Dimitre
>
> On Wed, Feb 17, 2021 at 5:32 PM Wolfhart
> Totschnig
> <mailto:wolfhart.totschnig@xxxxxxxxxxx>wolfhart.totschnig@xxxxxxxxxxx
> <<mailto:xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>xsl-list-service@xxxxxxxxxx
errytech.com>
> wrote:
> Dear list,
>
> I am facing an XPath problem for which I cannot find the solution. I
> want to select all following sibling elements of name "foo" up to the
> first non-"foo" element. So, in the following case, the first two <foo>
> elements should be selected:
>
> <foo/>
> <foo/>
> <bar/>
> <foo/>
>
> In the following case, all three <foo> elements should be selected:
>
> <foo/>
> <foo/>
> <foo/>
>
> And in the following case, nothing should be selected:
>
> <bar/>
> <foo/>
> <foo/>
>
> I came up with the following non-working approach:
>
> B B B B  B B B  B B B  <xsl:choose>
> B B B B  B B B  B B B  B B B  <xsl:when
> test="not(following-sibling::*[not(self::foo)])">
> B B B B  B B B  B B B  B B B  B B
> B  <xsl:value-of select="following-sibling::*"/>
> B B B B  B B B  B B B  B B B  </xsl:when>
> B B B B  B B B  B B B  B B B  <xsl:otherwise>
> B B B B  B B B  B B B  B B B  B B B  <xsl:value-of
> select="following-sibling::*[not(self::source)][1]/preceding-sibling::*[self
::source][preceding-sibling::current()]"/>
> B B B B  B B B  B B B  B B B  </xsl:otherwise>
> B B B B  B B B  B B B  </xsl:choose>
>
> That is, test whether there are non-"foo" following siblings. If there
> are none, take all following siblings. If there are, go forward to the
> first non-"foo" sibling, and from there go backwards, taking all the
> "foo" siblings up to the current node.
>
> But this does not work. Apparently, the expression
> "preceding-sibling::current()" is not a valid construct. So what is the
> correct way to do what I have in mind (or a simpler solution, if there
> is one). Please note that this stylesheet needs to be executed by a web
> browser, and so the solution has to remain within XPath 1.0.
>
> Thanks in advance for your help!
> Wolfhart
>
>
>
>
> --
> Cheers,
> Dimitre Novatchev
> ---------------------------------------
> Truly great madness cannot be achieved without significant intelligence.
> ---------------------------------------
> To invent, you need a good imagination and a pile of junk
> -------------------------------------
> Never fight an inanimate object
> -------------------------------------
> To avoid situations in which you might make mistakes may be the
> biggest mistake of all
> ------------------------------------
> Quality means doing it right when no one is looking.
> -------------------------------------
> You've achieved success in your field when you
> don't know whether what you're doing is work or play
> -------------------------------------
> To achieve the impossible dream, try going to sleep.
> -------------------------------------
> Facts do not cease to exist because they are ignored.
> -------------------------------------
> Typing monkeys will write all Shakespeare's
> works in 200yrs.Will they write all patents, too? :)
> -------------------------------------
> Sanity is madness put to good use.
> -------------------------------------
> I finally figured out the only reason to be alive is to enjoy it.
> B
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