The event library provides functions for understanding an event and the environment in which it was raised. For historical reasons, some of these are Web-centric. The following functions are available:
- event:env(). event:env() returns information about the event's environment. The function takes an argument that determines what will be returned:
- caller. Causes event:env() to return the URL of the Web page on which the event is firing (assumes a web event)
- ip. Causes event:env() to return the IP number of the endpoint (client).
- referer. Causes event:env() to return the URL of the referring page to the caller (assumes a web event).
- title. Causes event:env() to return the page title of the calling page.
- txn_id. Causes event:env() to return the transaction ID of this ruleset evaluation.
- event:attr(). event:attr() returns a specific event attribute. The function takes the name of the attribute to be returned as its sole argument.
- event:attrs(). event:attrs() returns all the event attributes as a map.