Feature request from CodeMonkey90, posted on GitHub Aug 04, 2014
Some time ago, I've written a module that generates a "category" page (product list) for each manufacturer. Naturally, our client wanted to be able to add CMS blocks to certain manufacturer pages, so I made my extension generate layout handles and took a look at the Widget Instance editor to figure out how to extend the "Layout Updates" chooser properly to allow users to select certain manufacturers like you can already select products and categories. After looking at the code for some hours (especially the JavaScript code), I eventually gave up and added another grid to the backend which allows users to associate manufacturers with CMS Blocks.
The solution I ended up with is not very flexible and kind of defeats the purpose of the "Widget Instance" admin page. It would be great if that could actually be a centralized point where users could add Widgets to arbitrary pages, like it's supposed to be. But so far, there doesn't seem to be a way to extend it properly for modules which generate layout handles dynamically. It would be great for both module developers and admin users if this possibility could be added.