Whitespace and xsl:text¶

Sooner or later your output grows a stray space, a run of blank lines, or indentation you never asked for. Almost always the cause is whitespace — in the stylesheet, in the source document, or added by the serialiser. This page shows where each kind of whitespace comes from and the small tools that let you control it: xsl:text, xsl:strip-space / xsl:preserve-space, normalize-space(), and xsl:output indent.

Whitespace in the stylesheet¶

A whitespace-only text node sitting between XSLT elements is stripped from the stylesheet automatically. The indentation that makes your stylesheet readable therefore does not reach the output:

<xsl:template match="cd">
  <xsl:value-of select="title"/>
  <xsl:value-of select="artist"/>
</xsl:template>

The newlines and spaces around the two xsl:value-of elements are whitespace-only nodes between instructions, so they are discarded. The title and artist come out glued together:

The one exception is text inside xsl:text — that is never stripped (see below). Everything else that is whitespace-only between elements goes away.

<line>
  <xsl:value-of select="title"/>
</line>

xsl:text — emit text exactly¶

xsl:text writes its content to the output verbatim, and its content is exempt from the whitespace-stripping rule. That makes it the precise tool for two jobs: forcing a space (or newline) to appear, and stopping unwanted whitespace from appearing.

Force exactly one space¶

To put a single space between two values, do not rely on the layout of your stylesheet — wrap the separator in xsl:text:

<xsl:value-of select="title"/><xsl:text> </xsl:text><xsl:value-of select="artist"/>

The space inside <xsl:text> </xsl:text> is real content, so it is emitted exactly once:

A literal newline works the same way — <xsl:text>&#10;</xsl:text> emits one line break, which is the usual way to end a record in method="text" output.

Suppress unwanted whitespace¶

An empty <xsl:text/> outputs nothing, but it is an element. Placing it between two values lets you spread instructions across several indented lines while the whitespace between them stays whitespace-only (and so is stripped):

<xsl:value-of select="title"/>
<xsl:text/>                       <!-- (1)! -->
<xsl:value-of select="artist"/>

1. The newlines either side of <xsl:text/> are whitespace-only text between elements, so they are removed — the two values join with nothing between them, even though the source is nicely indented.

Whitespace in the source document¶

Whitespace in the input is a separate question. By default the processor treats text nodes in the source as significant — even ones that are only indentation. A pretty-printed source therefore carries stray newlines and spaces in its text nodes.

Two top-level elements control this:

• xsl:strip-space elements="..." — remove whitespace-only text nodes from the listed source elements.
• xsl:preserve-space elements="..." — keep them (the default for everything).

Both take a space-separated list of element names, or * for all elements:

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<xsl:stylesheet version="1.0"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:strip-space elements="*"/>          <!-- (1)! -->
  <xsl:preserve-space elements="title"/>   <!-- (2)! -->

</xsl:stylesheet>

1. Drop whitespace-only text nodes from every source element — the indentation between <catalog>, <cd> and their children disappears, so things like count(node()) no longer trip over phantom text nodes.
2. Override the blanket strip for <title>, where you want any whitespace-only text kept.

normalize-space() — per-value cleanup¶

Stripping handles whole nodes; normalize-space() cleans a single string. It trims leading and trailing whitespace and collapses every internal run of spaces, tabs and newlines to one space. It is the standard defence against messy source text:

<xsl:value-of select="normalize-space(artist)"/>

If the source held <artist> Bob Dylan </artist>, the output is the tidy:

See String functions for the rest of the XPath 1.0 string toolbox.

Output indentation¶

xsl:output indent="yes" asks the serialiser to pretty-print the result tree by adding its own newlines and indentation:

<xsl:output method="xml" indent="yes"/>

This is purely for human readability of the result.

See Producing XML output for the full xsl:output reference.

disable-output-escaping¶

Normally the serialiser escapes special characters: a < in your text becomes <, an & becomes &. disable-output-escaping="yes" on xsl:value-of or xsl:text turns that off, so the characters are written raw:

<xsl:text disable-output-escaping="yes">&lt;hr/&gt;</xsl:text>

Instead of the visible text <hr/>, this writes the raw markup <hr/> into the output stream.

Worked example: title and artist, controlled separator¶

The shared catalog.xml:

<catalog>
  <cd><title>Empire Burlesque</title><artist>Bob Dylan</artist><price>10.90</price></cd>
  <cd><title>Hide your heart</title><artist>Bonnie Tyler</artist><price>9.90</price></cd>
</catalog>

We want one line per CD, title — artist, with exactly one space either side of the dash. The xsl:text separators make the spacing explicit, and a final <xsl:text>&#10;</xsl:text> ends each line:

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<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="text"/>
  <xsl:strip-space elements="*"/>          <!-- (1)! -->

  <xsl:template match="/catalog">
    <xsl:for-each select="cd">
      <xsl:value-of select="title"/>
      <xsl:text> — </xsl:text>             <!-- (2)! -->
      <xsl:value-of select="artist"/>
      <xsl:text>&#10;</xsl:text>           <!-- (3)! -->
    </xsl:for-each>
  </xsl:template>
</xsl:stylesheet>

1. Drop indentation from the source so no phantom text nodes leak through.
2. The separator — space, em dash, space — emitted exactly as written.
3. A literal newline ends the record.

Now compare the same template without xsl:text, relying on stylesheet layout for the spacing:

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<xsl:template match="/catalog">
  <xsl:for-each select="cd">
    <xsl:value-of select="title"/> — <xsl:value-of select="artist"/>
  </xsl:for-each>
</xsl:template>

The — here sits in a text node that also holds the surrounding spaces and newlines. Because that node is not whitespace-only (it contains the dash), its whitespace is kept — including the newline and indentation before the next iteration's title. The records run together with ragged spacing:

The lesson: when spacing matters, say it with xsl:text rather than letting the shape of the stylesheet decide.

Next¶

Template modes — once whitespace is under control, modes let you process the same nodes more than once, each pass producing a different kind of output.