Invoking Custom Actions

Custom actions are invoked in the same manner as standard actions, either by explicit invocation or during the execution of a sequence table. There are two methods for calling actions:

• You call the specified action directly with the MsiDoAction function.
• A top-level action calls the sequence table containing the custom action. For more information about scheduling a custom action in a sequence table, see Sequencing Custom Actions.

When the installer obtains an action name from the MsiDoAction function, or from a sequence table, it first searches for a standard action of that name. If it cannot find the standard action, then the installer queries the CustomAction table to check if the specified action is a custom action. If the specified action is not a custom action, then the installer queries the Dialog table for a dialog box.