Automatically indent an XML file using XSLT

Tip 551 Printable Monobook Previous Next

created September 5, 2003 · complexity advanced · author yijun · version 5.7

Do you want to indent an XML file? Try the following XSLT (say file named indent.xsl):

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output method="xml" indent="yes"/>
 <xsl:strip-space elements="*"/>
 <xsl:template match="/">
  <xsl:copy-of select="."/>
 </xsl:template>
</xsl:stylesheet>

In Vim, whenever a file with the ".xml" extension is loaded into the buffer, you can try the following in your vimrc to trigger the XSLT for filtering the buffer contents:

if version >= 540
  augroup filetype
    autocmd FileType xml '[,']!xsltproc indent.xsl %
  augroup END
endif
" other autocmds
if version>540
  autocmd!
endif

Next time when you load an XML file in Vim, it will be indented automatically.

xsltproc is a command line tool that is part of the gnome libxslt. See http://xmlsoft.org/XSLT.html

Comments[]

Using an XSLT which copies the document (not the file) is a common way to get pretty-printed XML.

Here are some more tips, variations, and alternatives:

If you don't have a copy of XSLT, you can use the following to indent XML/HTML:

:%s/></>\r</g
gg=G

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output method="xml" indent="yes"/>
 <xsl:strip-space elements="*"/>
 <xsl:template match="/">
  <xsl:copy-of select="."/>
 </xsl:template>
</xsl:stylesheet>