In XSLT, some characters are not allowed in certain contexts. For example, you cannot use the less than sign (<) and the ampersand (&) in the text between tags or in an attribute value. The XSLT transformation engine will give you an error if those characters are used incorrectly. To solve the problem, you can specify character entities to replace the special characters.
A character entity is a string of characters that represents other characters. Character entities are either named or numbered. A named entity begins with an ampersand (&) followed by the name or characters, and ends with a semicolon (;). For example, < represents the left angle bracket character (<). Numbered entities also start and end the same way, except that a hash sign (#) and a number specifies the character.
Character |
Entity Code |
---|---|
< (less-than) |
< |
& (ampersand) |
& |
> (greater-than) |
> |
" (quote) |
" |
‘ (apostrophe) |
' |
If you use other character entities in an XSL file, you need to define them in the DTD section of the XSL file. Dreamweaver provides several default entity definitions that you can see at the top of an XSL file created in Dreamweaver. These default entities cover a broad selection of the most commonly used characters.
When you preview your XSL file in a browser, Dreamweaver checks the XSL file for undefined entities and notifies you if an undefined entity is found.
Reference to undefined entity 'auml'. Error processing resource 'http://localhost/testthis/list.xsl'. Line 28, Position 20 <p class=''test''>ä</p> -------------------^
To correct the error in your page, you must add the entity definition to your page manually.