Extension Installer/Triggers/onAfterExtensionInstall
From Joomla! Documentation
< Extension Installer | Triggers
The onAfterExtensionInstall trigger occurs after the installation of an extension. It has a single parameter:
- installer
A copy of the installer instance that was used. This it to get access to any error messages that might have occured. - eid
The extension ID of the installed extension. The extension ID may be either a valid numeric value (positive integer), a zero value (when the extension doesn't have a corresponding entry in the extensions table but it is valid; a combined 1.5 language pack behaves this way) or false if the installation failed.