What is the easiest way to add a custom button to toolbar, with access to content item? I already check : Toolbar item for delete - for 2sxc module But because delete is not possible with already defined buttons, I like to make my own button.
As of now there is no official way to do this. It's easy, but since not official, it could break one day.
Basically all the buttons are provided from here: https://github.com/2sic/2sxc/blob/master/src/inpage/2sxc._actions.js
As you can see, there is a function $2sxc._actions.create
which will get all the actions possible for something, based on what that something is. So you could either