xml - How to use XSL 1.0 to Group Elements by Content -

so need group content using xsl 1.0. in specific use case, need convert following:

<elementfoo name='1'>     <bar>groupa</bar> </elementfoo> <elementfoo name='2'>     <bar>groupb</bar> </elementfoo> <elementfoo name='3'>     <bar>groupc></bar> </elementfoo> <elementfoo name='4'>     <bar>groupa</bar> </elementfoo> <elementfoo name='5'>     <bar>groupa</bar> </elementfoo> <elementfoo name='6'>     <bar>groupc></bar> </elementfoo> 

and need output this:

group a:

foo 1

foo 4

foo 5

group b:

foo 2

group c:

foo 3

foo 6

basically, need order things according content in specific child element, i'm not entirely sure how without bunch of if statements. there can large number of groups, , number of groups not known.

the following xsl should group foo's requested, , don't need bother pesky keys! modified xml (to add root element, , fix name of groupc), , made assumption how want output xml. let me know if helps:

source xml

<root>   <elementfoo name='1'>     <bar>groupa</bar>   </elementfoo>   <elementfoo name='2'>     <bar>groupb</bar>   </elementfoo>   <elementfoo name='3'>     <bar>groupc</bar>   </elementfoo>   <elementfoo name='4'>     <bar>groupa</bar>   </elementfoo>   <elementfoo name='5'>     <bar>groupa</bar>   </elementfoo>   <elementfoo name='6'>     <bar>groupc</bar>   </elementfoo> </root> 

xsl transformation

<xsl:template match="/root">     <root>         <xsl:for-each select="//bar[not(.=preceding::*)]">         <xsl:variable name="groupname" select="." />         <xsl:element name="{$groupname}">             <xsl:for-each select="//elementfoo[bar=$groupname]">             <foo><xsl:value-of select="@name" /></foo>             </xsl:for-each>         </xsl:element>         </xsl:for-each>     </root> </xsl:template> 

output xml

<root xmlns="http://www.w3.org/1999/xhtml">   <groupa>     <foo>1</foo>     <foo>4</foo>     <foo>5</foo>   </groupa>   <groupb>     <foo>2</foo>   </groupb>   <groupc>     <foo>3</foo>     <foo>6</foo>   </groupc> </root> 

a quick explanation:

1. the first for-each, iterates on each distinct bar value once (i.e. 'groupa', 'groupb', 'groupc')
2. the variable groupname, stores group's name (e.g. 'groupa')
3. the element tag, creates element group (e.g. <groupa>)
4. the second for-each, iterates on elementfoo's have bar value equal $groupname
5. and finally, value-of prints out @name current elementfoo

simple enough?