Internal plugin approach

General guidelines

The plugin code should be written in ES6. The currently supported ES6 features are (listed in our documentation)[http://docs.handsontable.com/tutorial-seven-principles.html],
Your class has to extend the BasePlugin class,
Your plugin files need to be places under src/plugins/nameOfYourPlugin/ directory to be properly recognized by our builder,
You need to make your own Handsontable build to incorporate your changes into the Handsontable source. Learn how to do it in our documentation.

Copy the internalPluginSkeleton.js file and rename it to describe your plugin. Let's use myPlugin.js for this example.
Change the class name to fit the filename, in our case:

class MyPlugin extends BasePlugin