functx:if-absent
The first argument if it is not empty, otherwise the second argument
Description
The functx:if-absent function is useful for providing default values in case a data item is absent. It checks if the $arg argument is the empty sequence, and if it is, it returns the value $value. Otherwise, it returns the typed value of $arg itself. Note that an element or attribute is not considered “absent” if it contains a zero-length string; only if it does not exist at all.
Note: This function is similar to the eg:if-absent function provided in the XQuery 1.0 and XPath 2.0 Functions and Operators document. However, this function differs in that it supports attribute nodes and atomic values.
Parameters |
Description |
|---|---|
arg:item() |
the item(s) that may be absent |
value:item() |
the item(s) to use if the item is absent |
Examples
XPath |
Results |
|---|---|
data(functx:if-absent($in-xml//price[1]/@discount, 0)) |
10.00 |
data(functx:if-absent($in-xml//price[3]/@discount, 0)) |
0 |
data(functx:if-absent($in-xml//price[4]/@discount, 0)) |
zero-length untyped value |