See the description of the eventListener extension.
The source code of the plugin, together with comments and an instruction for development and installation, is here.
The plugin is in the dcore-app-extension-el-test directory.
This extension reacts to events in the Editor and Administrator Application and displays a dialog box for each of them with the information about the type of the event and about the object for which the event took place (the information is taken from the dLibra server). A sample result of the operation of that plugin, for an event pertaining to a change of the properties of a release, is shown in the image below.
