Data Source Variables

Data source variables are Hawk variables that represent the return fields of a microagent method. The method must be used as the data source of the current rule. You can reference data source variables only in actions.

For example, the Hawk Services sample rulebase provides a rule for monitoring an event log and sending a high-level alert message when an error is written to the log. The Alert action type used in this rule allows you to specify a text string for the alert message. In this example, the text string is:

Hawk Agent : ${nextLine}

where ${nextLine} is the text of the error message in the log. nextLine is a label for values returned by the microagent method that extracts information from the log file. Without variable substitution, you can include only static text, such as High level alert or a similar string, in the alert message.