17.20 About trigger variables
Trigger variables are pieces of information that pass from trigger to trigger. They allow triggers to fire based on another trigger's behavior, state, and/or output. A variable can be a required condition for a trigger to fire; for instance, a trigger might be set to launch when a reservation starts, but only if it has received a variable from another trigger indicating that a specific node has started first. Variables give greater flexibility and power to a site administrator who wants to automate certain tasks and system behaviors.
Variables can be used to define under what circumstances the trigger will fire. Many Moab objects have their own variables and each object's variable name space is unique. Triggers can use their own variables or the variables attached to their parent objects. A trigger's variable name space is limited to itself and its parent object. Variables do not have to be unique across all objects.
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