How do I execute code before updating nodes?
I am looking for a hook to use in a custom module.
I have created a content type. What I need to do is execute a hook before updating any content. I want to keep the history of every content, so I want to execute some code before updating, which will compare previous and currently update record. If there is any change, I want to insert it in another table.
I also want to show that history on the content detail page.