HP e-Commerce / XML director server appliance sa8250 - Users Guide

C H A P T E R 2 XML Operations
21
Values
Values are used to specify the right operand of a comparison
expression, and can be either a literal (such as a string) or a number.
A literal has to be enclosed either in single or double quotes. If the
literal string contains a single quote, double quotes should be used to
enclose the string. If the literal string contains double quotes, single
quotes should be used to enclose the string. Character references
(both decimal and hexadecimal format) and predefined entities as
described in the XML specification can be used within the literal
string.
The string value of the left operand is obtained for literal equality
comparisons. If an element is specified for the left operand, only
elements without a child element should be used. Although the upper
level elements are not supported, this generally is not a problem,
since in most cases only the lowest level element contains text values.
A number can be either a decimal number or an integer. Numbers
should not be enclosed in quotes. If a number is enclosed in quotes,
it is treated as a literal. A number can be signed by proceeding it with
a ’+’ or ’-’ sign. A decimal number must contain only one decimal
point with at least one digit.
A numeric comparison is either an equality comparison with a
numeric right operand or a non-equality comparison. Both the value
of the left and right operands, if needed, are converted to numeric
values before a numeric comparison is made. If the value cannot be
converted to a number, the comparison returns false.