Inserting a line break in a PDF generated from XSL FO using <xsl:value-of>

Question

I am using XSL FO to generate a PDF file containing a table with information. One of these columns is a "Description" column. An example of a string that I am populating one of these Description fields with is as follows:

This is an example Description.<br/>List item 1<br/>List item 2<br/>List item 3<br/>List item 4

Inside the table cell that corresponds to this Description, I would like the output to display as such:

This is an example Description.
List item 1
List item 2
List item 3
List item 4

I've learned from searching elsewhere that you can make line breaks in XSL FO using an <fo:block></fo:block> within another <fo:block> element. Therefore, even before I parse the XML with my XSL stylesheet, I replace all occurrences of <br/> with <fo:block/>, so that the literal value of the string now looks like:

This is an example Description.<fo:block/>List item 1<fo:block/>List item 2<fo:block/>List item 3<fo:block/>List item 4

The problem arises when the Description string I am using is obtained using <xsl:value-of>, example as follows:

<fo:block>
    <xsl:value-of select="descriptionStr"/>
</fo:block>

In which case, the value that gets output to my PDF document is the literal value, so it looks exactly like the previous example with all the <fo:block/> literals. I've tried manually hard-coding the <fo:block/> in the middle of another string, and it displays correctly. E.g. if I write inside my stylesheet:

<fo:block>Te<fo:block/>st</fo:block>

It will display correctly as:

Te
st

But this does not seem to happen when the <fo:block/> is inside the value of an <xsl:value-of select=""/> statement. I've tried searching for this on SO as well as Google, etc. to no avail. Any advice or help will be greatly appreciated. Thank you!

Answer 1

I had a text block that looks like this

<fo:table-cell display-align="right">
<fo:block font-size="40pt" text-align="right">
    <xsl:text> Text 1 </xsl:text>
    <fo:block> </fo:block>
    <xsl:text> Text2 </xsl:text>
    <fo:block> </fo:block>
    <xsl:text> Text 3</xsl:text>
</fo:block>

NB: note the empty

Answer 2

I usually use an empty block with a height that can be changed if I need more or less space:

<fo:block padding-top="5mm" />

I know this isn't the best looking solution but it's funtional.

Answer 3

Generating strings containing escaped XML markup is seldom the right answer, but if that's what you have to work with, then for input like this:

<Description><![CDATA[This is an example Description.<br/>List item 1<br/>List item 2<br/>List item 3<br/>List item 4]]></Description>

if you're using XSLT 2.0, you can use xsl:analyze-string to get the empty fo:block that you originally wanted:

<xsl:template match="Description">
  <fo:block>
    <xsl:analyze-string select="." regex="&lt;br/>">
      <xsl:matching-substring>
        <fo:block />
      </xsl:matching-substring>
      <xsl:non-matching-substring>
        <xsl:value-of select="." />
      </xsl:non-matching-substring>
    </xsl:analyze-string>
  </fo:block>
</xsl:template>

but if you are using XSLT 2.0, you can more concisely use linefeed-treatment="preserve" as per @Daniel Haley and use replace() to insert the linefeeds:

<xsl:template match="Description">
  <fo:block linefeed-treatment="preserve">
    <xsl:value-of select="replace(., '&lt;br/>', '&#xA;')" />
  </fo:block>
</xsl:template>

If you are using XSLT 1.0, you can recurse your way through the string:

<xsl:template match="Description">
  <fo:block linefeed-treatment="preserve">
    <xsl:call-template name="replace-br" />
  </fo:block>
</xsl:template>

<xsl:template name="replace-br">
  <xsl:param name="text" select="." />

  <xsl:choose>
    <xsl:when test="not(contains($text, '&lt;br/>'))">
      <xsl:value-of select="$text" />
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="substring-before($text, '&lt;br/>')"/>
      <xsl:text>&#xA;</xsl:text> <!-- or <fo:block /> -->
      <xsl:call-template name="replace-br">
        <xsl:with-param name="text" select="substring-after($text, '&lt;br/>')"/>
      </xsl:call-template>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

Answer 4

Try using linefeed-treatment="preserve" and \n instead of <br> for a new line.

<fo:block linefeed-treatment="preserve" >
 <xsl:value-of select="Description" />
</fo:block>

Answer 5

For XSLT 1.0 I'm using my XSLT Line-Break Template on GitHub.

For XSL-FO it supports

• Line breaks
• Line delimiters (vs Line breaks)
• Series of pointers in a row
• Ignore Pointer Repetitions (disable the Series of pointers in a row)
• Any string as a pointer to insert a break or a delimiter ("\n" is default)
• Line delimiters' height
• Default Line delimiter height from a current font size.
• Auto ignoring of the "\r" char when searching a break place.
• Added support for XSLT 2.0 for a seamless migration.
• something else...

For XSLT 2.0 and later consider to use approaches like

• XSLT 2.0 xsl:analyze-string (RegEx)
• XPath 2.0 tokenize + XSLT (RegEx)
• passing sequences as a template parameter (XSLT 2.0)
• and so on

Answer 6

This helped me and should be simplest solution (working with Apache FOP 1.1):

Why not replace your <br/> with Unicode character called line separator.

   <xsl:template match="br">
      <xsl:value-of select="'&#x2028;'"/>
   </xsl:template>

See https://en.wikipedia.org/wiki/Newline#Unicode

Answer 7

The following code worked:

<fo:block white-space-collapse="false" 
    white-space-treatment="preserve" 
    font-size="0pt" line-height="15px">.</fo:block>

It makes the xsl processor thinks this block contains a line of text, which actually has a 0pt font size. You can customize line height by providing your own value.

Answer 8

Try this:

<fo:block><fo:inline color="transparent">x</fo:inline></fo:block>

This code adds a block which contains transparent text, making it look like a new line.

Answer 9

You could also replace <br/> with 
 and add a linefeed-treatment="preserve" attribute to your <fo:block>.

Something like:

<fo:block linefeed-treatment="preserve">This is an example Description.&#xA;List item 1&#xA;List item 2&#xA;List item 3&#xA;List item 4</fo:block>

Edit

Some users may need to use \n instead of 
 depending on how they are creating the XML. See Retain the &#xA; during xml marshalling for more details.

Answer 10

</fo:block> on it's own is not a direct substitute for <br/> <br/> is an html unpaired abberation that has no direct equivalent in xsl:fo

</fo:block> just means end of block. If you scatter them through your text you wont have valid xml, and your xsl processor will sick up errors.

For the line break formatting you want, each block will occur on a new line. You need a <fo:block> start block and </fo:block> end block pair for each line.

Answer 11

You shouldn't use xsl:value-of instruction but xsl:apply-templates instead: for built-in rule for text node will just output their string value, and for empty br element you could declare a rule matching descriptionStr/br or descriptionStr//br (depending your input) in order to transform to empty fo:block.