Re: [xsl] Escaping Curly Braces in Regex

[Martin Honnen <Martin.Honnen@xxxxxx>]

rowan@xxxxxxxxxxxxxxxxxxxxx wrote:

> I found it very confusing that one requires the {} to be doubled and the
> other doesn't. Where is it documented which attributes require braces to be
> doubled up and which do not?

If you look at
 http://www.w3.org/TR/xslt20/#analyze-string
then it has the following definition:

<xsl:analyze-string
  select = expression
  regex = { string }
  flags? = { string }>
  <!-- Content: (xsl:matching-substring?, xsl:non-matching-substring?, 
xsl:fallback*) -->
</xsl:analyze-string>

so the attribute definition in the form of
  regex = { string }
shows you that an attribute value template is expected while
  select = expression
only takes an XPath expression.

There is even a prose warning note in there:

Because the regex attribute is an attribute value template, curly 
brackets within the regular expression must be doubled. For example, to 
match a sequence of one to five characters, write regex=".{{1,5}}". For 
regular expressions containing many curly brackets it may be more 
convenient to use a notation such as 
regex="{'[0-9]{1,5}[a-z]{3}[0-9]{1,2}'}", or to use a variable.

--

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/