XSLT- normalize non-breaking whitespace characters

Question

I have a sample xml file like this,

<doc>
    <p>text1 text2  </p>
    <p>text1 text2     </p>
    <p>text1 text2   </p>
</doc>

this sample xml, first <p> has space whitespace character ( ), second <p> has tab whitespace whitespace character (	) and third <p> has space non-breaking whitespace character ( ).

I need to remove the any white spaces appearing just before closing tag.

So, expected output should be,

<doc>
    <p>text1 text2</p>
    <p>text1 text2</p>
    <p>text1 text2</p>
</doc>

By using xslt normalize-space() I can remove unnecessary spaces and tab characters but not non-breaking whitespace characters.

<xsl:template match="p/text()">
    <xsl:value-of select="normalize-space()"/>
</xsl:template>

Any suggestions how can I normalize all white spaces including non-breaking white spaces in xslt?

Maccaboy

if you have a list of the potential non-breaking charactes, you could do a translate() of those to a normal space before calling the normalize-space – Polyhydroxy

Answer 1

You could do:

<xsl:value-of select="normalize-space(translate(., '&#160;', ' '))"/>

This will work in XSLT 1.0 and 2.0 alike.

---

In XSLT 2.0, you could also use regex - for example:

<xsl:value-of select="replace(., '[\t\p{Zs}]', '')"/>

will remove the horizontal tab character as well as any character in the Unicode Space_Separator category, which includes not only the space and non-breaking space characters but also other space characters. Documentation is hard to find, but I believe this is currently the complete list: (extracted from http://www.unicode.org/Public/UNIDATA/UnicodeData.txt):

  SPACE
  NO-BREAK SPACE
  OGHAM SPACE MARK
  EN QUAD
  EM QUAD
  EN SPACE
  EM SPACE
  THREE-PER-EM SPACE
  FOUR-PER-EM SPACE
  SIX-PER-EM SPACE
  FIGURE SPACE
  PUNCTUATION SPACE
  THIN SPACE
  HAIR SPACE
  NARROW NO-BREAK SPACE
  MEDIUM MATHEMATICAL SPACE
　 IDEOGRAPHIC SPACE

𐲰 OLD HUNGARIAN CAPITAL LETTER EZS
𐳰 OLD HUNGARIAN SMALL LETTER EZS
𖼶 MIAO LETTER ZSHA
𖼼 MIAO LETTER ZSA
𖼾 MIAO LETTER ZZSA
𖽁 MIAO LETTER ZZSYA

However, testing with Saxon 9.5 shows that the last 6 characters are not recognized: http://xsltransform.net/ncntCSo

Sophiasophie

I'd never come across Unicode Categories before in Regex so reading regular-expressions.info/unicode.html helped me understand \p{Zs} . – Donelu