How do I integrate with bbCode Buttons?
BBcode Buttons are the buttons for BBcode (rather than HTML, glad you followed me there).
In BBcode-buttons.php
Find: BBcodeButtons.push(new BBcodeButton('ed_li','LI','[]','[/]','l','','list item'));";
Add below: BBcodeButtons.push(new BBcodeButton('ed_spoiler','SPOILER','[spoiler]','[/spoiler]','r','','spoiler'));";
In BBcode-buttons.js
In my theme I can't see the spoiler even if I'm hovering over it, how do I fix this?
That's easy, in the code you added to the style.css file of your theme change .spoiler:hover{color:black;background:transparent;} to .spoiler:hover{color:white;background:transparent;}
You can change white to any colour code you want the text to be when you hover over it.