XPath Functions

Functions provided by XPath 1.0 that can be used in XSL mappings

Arguments within [squared brackets] are optional.

Node-set Functions

count(node-set)		Returns an integer number with the number of nodes in `node-set`.
id (Id)		Selects the node with the unique ID specified in `Id`. Example: `<xsl:value-of select="id('abc')/child::para"/>` Selects the child node `para` of the node with the unique ID `abc.`
last ()		Returns an integer number with the position number of the last node in the current context. Example: `<xsl:if test="position() = last()">` checks, if the current node is the last node.
local-name ([node-set])		Returns a string with the local part of a node name with namespace declaration. The optional argument `node-set` specifies a node-set.
name ([node-set])		Returns a string with the name of the current node. The optional argument `node-set` specifies a node-set.
namespace-uri ([node-set])		Returns a string with the namespace URI (Uniform Resource Identifier) of the current element or attribute node. The optional argument `node-set` specifies a node-set. Example: `<xsl:value-of select="namespace-uri()"/>` Returns the namespace URI (if existing) of the current node.
position ()		Returns an integer number with the position of the current node. The first node has the position number `1`.

Boolean Functions

Boolean XPath functions return true/false values and can be combined with logical operators.

boolean (Arg)		Checks if argument `Arg` is true and returns a boolean value. All arguments that are a positive number, a non-empty string or a non-empty node-set, will be interpreted as `true`.
false ()		Returns `false`.
lang (Arg)		Returns `true`, if the language specified in argument `Arg` matches at least partially the language that has been specified in an `xml:lang` attribute. Example: `lang("en")` returns `true`, if the current node contains the attribute `xml:lang="en"` or matches partially like x`ml:lang="en-US"`.
not (Arg)		Returns the negation of a boolean expression in argument `Arg`. Example: `<xsl:if test="not(element > 1)">` returns `true`, if the content of `element` is less or equal to `1`.
true ()		Returns `true`.

Number Functions

XPath number functions return integer numbers and can be combined with logical operators.

ceiling (Arg)		Rounds up a number within the argument `Arg` to the next higher integer number and returns this integer number (e. g. `0.001` to `1`). If necessary, the argument will be converted to a number first. Mathematically correct: Returns the smallest integer number that is not smaller than the argument `Arg`.
floor (Arg)		Rounds down a number within the `Arg` to the next lower integer number and returns this integer number (e. g. `0.999` to `0`). If necessary, the argument will be converted to a number first. Mathematically correct: Returns the biggest integer number that is not bigger than the argument `Arg.`
number ([Arg])		Converts the current node's content into a number and returns this number. Optionally, the argument `Arg` can specify a node-set, string, boolean value or another object to be converted. Boolean values `true` and `false` will be converted to `1` and `0`. Example: A string `3xy` will be converted to `3`; `xy` will be interpreted as `NaN` (Not a Number).
round (Arg)		Rounds a number within the argument `Arg` to the next positive or negative integer number and returns this number. Numbers lower than `[value].5` will be rounded down, fractions greater or equal `[value].5` will be rounded up to the next higher integer number. Example: `0.49` will be rounded down to `0`, `-1.5` will be rounded up to `-1`.
sum (node-set)		Creates the total sum of all node contents of the argument `node-set` and returns it as number. If necessary, the node contents will be converted to numbers first. Values that cannot be interpreted as numbers will be handled as `NaN` (Not a Number).

String Functions

XPath string functions handle objects and return strings or boolean values when evaluating strings.

concat (Arg1, Arg2 [, ...] )		Joins multiple strings that are handed over as arguments `Arg1, Arg2` etc. and returns a string. If necessary, all arguments will be converted to a string first.
contains (Arg, Substring)		Checks if the argument `Substring` is contained within the argument `Arg` and returns a boolean value. If necessary, all arguments will be converted to a string first. Example: `<xsl:if test="contains('SoftProject', 'Project')">` returns the boolean value true.
starts-with (Arg, Substring)		Checks if the argument `Arg` starts with the argument `Substring` and returns a boolean value. If necessary, all arguments will be converted to a string first. Example: `<xsl:if test="starts-with('SoftProject', 'Soft')">` returns the boolean value true.
normalize-space ([Arg])		Removes leading and trailing whitespaces of the current node content, replaces multiple whitespaces, tabulators and line breaks with a single whitespace, and returns the node content as string. Optionally, an argument `Arg` can be used, which will be converted to a string, if required.
string ([Arg])		Converts the current node content into a string and returns this string. Optionally, the argument `Arg` may contain boolean values that will be converted to `true` or `false`. Decimal numbers will be simplified, if possible. Use the XSLT function `formatnumbers()` for all further number-to-string conversions. Example: `<xsl:value-of select="string(4.00)"/>` returns the string 4. Check if the value is a number: `<xsl:if test="string(number(@value))!='NaN'">`.
string-length ([Arg])		Returns an integer number with the number of characters of the current node content. If necessary, all arguments will be converted to a string first. Optionally, an argument `Arg` can be used, which will be converted to a string, if required.
substring (Arg, Start, [length])		Extracts a substring of the argument `Arg` starting from the character `Start`, and returns a string. The character counting starts with `1`. Optionally, the argument `Length` can be used, which specifies the maximum length of the substring.
substring-before (Arg, Substring)		Checks if a string in argument `Arg` contains a substring within the argument `Substring` and returns a string with all characters that precede the substring. If `Substring` is not contained in `Arg`, an empty string will be returned. Example: `<xsl:value-of select="substring-before('2008/04/01', '/')"/>` returns 2008.
substring-after (Arg, Substring)		Checks if a string in argument `Arg` contains a substring within the argument `Substring` and returns a string with all characters that follow the substring. If `Substring` is not contained in `Arg`, an empty string will be returned. Example: `<xsl:value-of select="substring-after('2008/04/01', '20')"/>` returns 08/04/01.
translate (Arg, Substring1, Substring2)		Searches in argument `Arg` for a string within the argument `Substring1`, replaces this with the string within argument `Substring2`, and returns the modified string. If necessary, the argument `Arg` will be converted to a string first. Each matching character of `Substring1` will be replaced with the corresponding character from `Substring2`. Example: `<xsl:value-of select="translate('hello world', 'abcdefghijklmnopqrstuvwxyz', 'ABCDEFGHIJKLMNOPQRSTUVWXYZ')" />` returns HELLO WORLD.