What is the best way to include an html entity in XSLT?
&am
It is also possible to extend the approach from 2nd part of aku's answer and get all known character references available, like this:
<!DOCTYPE stylesheet [
<!ENTITY % w3centities-f PUBLIC "-//W3C//ENTITIES Combined Set//EN//XML"
"http://www.w3.org/2003/entities/2007/w3centities-f.ent">
%w3centities-f;
]>
...
<xsl:text> −30°</xsl:text>
There is certain difference in the result as compared to <xsl:text disable-output-escaping="yes">
approach. The latter one is going to produce string literals like
for all kinds of output, even for <xsl:output method="text">
, and this may happen to be different from what you might wish... On the contrary, getting entities defined for XSLT template via <!DOCTYPE ... <!ENTITY ...
will always produce output consistent with your xsl:output
settings.
It may be wise then to use a local entity resolver to keep the XSLT engine from fetching character entity definitions from the Internet. JAXP or explicit Xalan-J users may need a patch for Xalan-J to use the resolver correctly. See my blog XSLT, entities, Java, Xalan... for patch download and comments.
Now that there's Unicode, it's generally counter-productive to use named character entities. I would recommend using the Unicode character for a non-breaking space instead of an entity, just for that reason. Alternatively, you could use the entity  
;, instead of the named entity. Using named entities makes your XML dependent on an inline or external DTD.
this one returns a XsltParseError
Yes, and the reason for that is that
is not a predefined entity in XML or XSLT as it is in HTML.
You could just use the unicode character which
stands for:  
XSLT only handles the five basic entities by default: lt
, gt
, apos
, quot
, and amp
. All others need to be defined as @Aku mentions.
one other possibility to use html entities from within xslt is the following one:
<xsl:text disable-output-escaping="yes">&nbsp;</xsl:text>