XPath/XQuery iri-to-uri function


Converts a string containing an IRI into a URI according to the rules of .


$iri as xs:string?
) as xs:string


This function is deterministic, context-independent, and focus-independent.


If $iri is the empty sequence, the function returns the zero-length string.

Otherwise, the function converts the value of $iri into a URI according to the rules given in Section 3.1 of by percent-encoding characters that are allowed in an IRI but not in a URI. If $iri contains a character that is invalid in an IRI, such as the space character (see note below), the invalid character is replaced by its percent-encoded form as described in before the conversion is performed.

Since recommends that, for consistency, URI producers and normalizers should use uppercase hexadecimal digits for all percent-encodings, this function must always generate hexadecimal values using the upper-case letters A-F.


The expression fn:iri-to-uri ("http://www.example.com/00/Weather/CA/Los%20Angeles#ocean") returns "http://www.example.com/00/Weather/CA/Los%20Angeles#ocean".

The expression fn:iri-to-uri ("http://www.example.com/~bébé") returns "http://www.example.com/~b%C3%A9b%C3%A9".


The function is idempotent but not invertible. Both the inputs My Documents and My%20Documents will be converted to the output My%20Documents.

This function does not check whether $iri is a valid IRI. It treats it as an string and operates on the characters in the string.

The following printable ASCII characters are invalid in an IRI: "<", ">", " (double quote), space, "{", "}", "|", "\", "^", and "`". Since these characters should not appear in an IRI, if they do appear in $iri they will be percent-encoded. In addition, characters outside the range x20-x7E will be percent-encoded because they are invalid in a URI.

Since this function does not escape the PERCENT SIGN "%" and this character is not allowed in data within a URI, users wishing to convert character strings (such as file names) that include "%" to a URI should manually escape "%" by replacing it with "%25".