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Configuring Advanced Expressions: Getting Started
Advanced policies evaluate data on the basis of information that you supply in
advanced expressions. An advanced expression analyzes data elements (for
example, HTTP headers, source IP addresses, the NetScaler system time, and
POST body data).
To create an advanced expression, you select a prefix that identifies a piece of
data that you want to analyze, and then you specify an operation to perform on the
data. For example, an operation can match a piece of data with a text string that
you specify, or it can transform a text string into an HTTP header. Other
operations match a returned string with a set of strings or a string pattern. You
configure compound expressions by specifying Boolean and arithmetic operators,
and by using parentheses to control the order of evaluation. You can also include
classic expressions in an advanced expression.
Advanced expressions are typically part of a policy, and you can assign names to
frequently used expressions so that you do not have to enter the full expression
repeatedly in multiple policies. But for some features, you configure advanced
expressions outside the context of a policy.
In This Chapter
Expression Characteristics
Basic Elements of an Advanced Expression
Compound Advanced Expressions
Classic Expressions in Advanced Expressions
Configuring Advanced Expressions in a Policy
Configuring Named Advanced Expressions
Configuring Advanced Expressions Outside the Context of a Policy