To give users the ability to undo and redo changes that a plugin makes, set waypoints using the ChangeHistoryService. If the user doesn't have anything selected, it creates the new script in ServerScriptService.
The onNewScriptButtonClicked function checks if the user has anything selected and creates the new script as its child instead of inside ServerScriptService.
To modify a plugin's behavior based on what the user has selected, use the Selection service. In the code for EmptyScriptAdder, the connecting function is onNewScriptButtonClicked. To make the plugin execute code when a user clicks the toolbar button, connect a function to the button's PluginToolbarButton.Click event. In the code for EmptyScriptAdder, line 5 creates a new section in the toolbar named Custom Script Tools and line 8 creates a button named Create Empty Script. To add a button for your plugin to the Plugins tab of the Studio toolbar, use the Plugin:CreateToolbar() and PluginToolbar:CreateButton() methods. The Output window indicates that the plugin successfully saved and the plugin runs for the first time after you save it.
In the popup window, click Save to insert the plugin script into your local Plugins folder of the Studio installation.
