The xsl:value-of element evaluates an expression as a string,
and outputs its value to the current result tree.
The full syntax of expressions is outlined in XPath Expression Syntax.
The select attribute identifes the expression. If this is not specified, the value
to be output is obtained by evaluating the sequence constructor contained within the xsl:value-of
element.
The optional disable-output-escaping attribute may be set to "yes" or "no"; the default is
"no". If set to "yes", special characters such as "<" and "&" will be output as themselves,
not as entities. Be aware that in general this can produce non-well-formed XML or HTML. It is useful,
however, when generating things such as ASP or JSP pages. Escaping may not be disabled when writing
to a result tree fragment.
If the select expression evaluates to a sequence containing more than one item,
the result depends on whether a separator attribute is present. If the
separator is absent when running in 1.0 mode, then only the
first item is considered. When running in 2.0 mode, all the items are output. The separator
defaults to a single space if the select attribute is used, or to a zero-length string
if a sequence constructor is used. The separator attribute may be specified
as an attribute value template.
Here are some examples of expressions that can be used in the select attribute:
|
Expression |
value |
|
TITLE |
The character content of the first child TITLE element if there is one |
|
@NAME |
The value of the NAME attribute of the current element if there is one |
|
. |
The expanded character content of the current element |
|
../TITLE |
The expanded character content of the first TITLE child of the parent element, if there is one |
|
ancestor::SECTION/TITLE |
The expanded character content of the first TITLE child of the enclosing SECTION element, if there is one |
|
ancestor::*/TITLE |
The expanded character content of the first TITLE child of the nearest enclosing element that has a child element named TITLE |
|
PERSON[@ID] |
The content of the first child PERSON element having an ID attribute, if there is one |
|
*[last()]/@ID |
The value of the ID attribute of the last child element of any type, if there are any |
|
.//TITLE |
The content of the first descendant TITLE element if there is one |
|
sum(*/@SALES) |
The numeric total of the values of the SALES attributes of all child elements that have a SALES attribute |
