Remove parent element if there are no children

[CI]

I have the following XML file

<Book>
<Chapters>
<Chapter number="1"/>
<Chapter number="2"/>
</Chapters>
<Colors>
<Color RGB="255"/>
<Color RGB="211" name="Red"/>
<Color name="Yellow"/>
<Color RGB="127"/>
</Colors>
</Book>

I want to get a tree with the <Colorelement s that don't have RGB
attribute:

So I came up with this XSLT sheet.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:styleshe et version="1.0" xmlns:xsl="http ://www.w3.org/1999/XSL/
Transform">
<xsl:template match="@*|node( )">
<xsl:copy>
<xsl:apply-templates select="@*|node ()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="Color">

<xsl:choose>
<xsl:when test="@RGB">

</xsl:when>
<xsl:otherwis e>
<xsl:copy-of select="."/>
</xsl:otherwise>
</xsl:choose>

</xsl:template>

</xsl:stylesheet>

It works correctly, but if in my XML file all the <Colorelement s
have RGB attribute the resulted tree
contains empty <Colors></Colorsnode.

Anyone had an idea how to conditionally remove it?

Regards,

Michael

[Dimitre Novatchev]

"Joe Kesselman" <ke************ @comcast.netwro te in message
news:Y8******** *************** *******@comcast .com...

p.*****@ctncorp .com wrote:

>On a side note, XSLT2 is bliss:

A minor change, but a good one: XSLT removed the distinction between
Result Tree Fragments and Node Sets (both are now grouped together as
Temporary Trees), so one doesn't need the node-set extension to convert
the former into the latter.

Outside of that, this is the same two-past solution I suggested.

C'mon people,

Do you know how much additional memory such a solution may use? Twice the
memory of one-pass solution.

Where possible, do try to "fuse" (the term is "fusion" or "deforestation" ) a
pipeline of passes into a single pass.

And, of course, I am not rediscovering the wheel here...
Cheers,
Dimitre Novatchev.

[Joe Kesselman]

Dimitre Novatchev wrote:

Do you know how much additional memory such a solution may use? Twice the
memory of one-pass solution.

It may, or it may not, depending on the internal data model of the
processor. And for simple input documents, that really may not matter.

In fact, what I'd do if taking this approach was to do two-pass
processing only locally, on the element which requires it -- so the
overhead is both smaller and transient.

It can be taken further... but see first paragraph; before spending too
much effort on optimization, consider whether the improvement is worth
the effort. Learn to do it right, but also learn when good enough is
good enough.
--
() ASCII Ribbon Campaign | Joe Kesselman
/\ Stamp out HTML e-mail! | System architexture and kinetic poetry

[roy axenov]

On Apr 14, 6:26 pm, "Dimitre Novatchev"
<dimit...@tpg.c om.auwrote:

"Joe Kesselman" <keshlam-nos...@comcast. netwrote in
message
news:Y8******** *************** *******@comcast .com...

p.le...@ctncorp .com wrote:

On a side note, XSLT2 is bliss:

A minor change, but a good one: XSLT removed the
distinction between Result Tree Fragments and Node Sets
(both are now grouped together as Temporary Trees), so
one doesn't need the node-set extension to convert the
former into the latter.

Outside of that, this is the same two-past solution I
suggested.

Do you know how much additional memory such a solution
may use? Twice the memory of one-pass solution.

Where possible, do try to "fuse" (the term is "fusion" or
"deforestation" ) a pipeline of passes into a single pass.

I don't know about you, but premature optimization is a sin
in my book. Go for clarity and neatness first, deal with
performance issues as they arise.

--
roy axenov

[Joe Kesselman]

roy axenov wrote:

I don't know about you, but premature optimization is a sin
in my book. Go for clarity and neatness first, deal with
performance issues as they arise.

Especially when still teaching basic concepts.

Steve Boies: "Make it work, make it good, make it great."
(Chorus response: "In that order!")
--
() ASCII Ribbon Campaign | Joe Kesselman
/\ Stamp out HTML e-mail! | System architexture and kinetic poetry

[Dimitre Novatchev]

"Joe Kesselman" <ke************ @comcast.netwro te in message
news:99******** *************** *******@comcast .com...

roy axenov wrote:

>I don't know about you, but premature optimization is a sin
in my book. Go for clarity and neatness first, deal with
performance issues as they arise.

Especially when still teaching basic concepts.

Steve Boies: "Make it work, make it good, make it great."
(Chorus response: "In that order!")
--
() ASCII Ribbon Campaign | Joe Kesselman
/\ Stamp out HTML e-mail! | System architexture and kinetic poetry

Yes, and following all these recommendations I'd still prefer the most
compact and elegant solution (sorry, it happens to be the one I proposed
) )

I didn't spend any time trying to optimize -- just chose the most *natural*
solution, which for XSLT happens to be overriding the identity rule -- and
this is so for more than 90% of all cases.
Cheers,
Dimitre Novatchev.

[Joe Kesselman]

Dimitre Novatchev wrote:

I didn't spend any time trying to optimize -- just chose the most *natural*
solution, which for XSLT happens to be overriding the identity rule -- and
this is so for more than 90% of all cases.

I agree that this is the core starting point for most XSLT design.

--
() ASCII Ribbon Campaign | Joe Kesselman
/\ Stamp out HTML e-mail! | System architexture and kinetic poetry