Policy Server Guides › Policy Server Configuration Guide › User Directories › User Attribute Mapping › Define an Attribute Mapping › Expression

Expression

An expression attribute mapping lets you map a common name to an expression. The expression can contain one or more user attribute names specified by the user directory's underlying schema and must conform to the syntax rules of a SiteMinder expression.

Expression attribute mappings map common names to expressions that can be read, but not changed. This type of access is called read only (R). When evaluated, the expressions result in a string, number, or Boolean value.

Expression attribute mapping and virtual user attributes, one type of named expression, are similar in the following ways:

• Both are SiteMinder expressions.
• As expressions, both are read only (R).
• As expressions, both result in one of the following data types:
  • string
  • number
  • Boolean

Expression attribute mapping differs from virtual user attributes as follows:

• An expression attribute mapping is defined for particular user directories. Virtual user attributes are global and can be applied to any user in any user directory.
• Virtual user attributes must begin with the pound sign (#). An expression mapping does not.