Andy: I think your issue is with Apple using the same icon graphic for folders as groups. I think they are conceptially different but close enough to use the same icon (they are different colors, yellow vs blue). I think groups are more like playlists in iTunes or something. You can move stuff around but it doesn't change the physical location of the files on the hard drive.
After a bit of testing I found you can have sub-folders (in some cases) and use the project window to manage your files in Xcode as well as the finder, here is how:
Create a folder in the finder called main, inside this folder create a folder called images. Inside the image folder put some image files.
Create a new Xcode project (using the "Nimble Kit Application" template.
Take the main folder from the finder and drag it to the "Groups & Files" area in the project window (the one seen in Andy's screen shot above). I used these settings to import my folder:

- image_1.jpg (10.1 KiB) Viewed 458 times
It will then make a copy of your folder inside your project folder in the finder, as well as make the blue folders in Xcode.
Then edited main.html to have something like:
- Code: Select all
<img src="main/images/image_2.png" />
Now to add more images you simply have to add them to the image folder in the finder. You might have to close and reopen the 'triangle' icon next to the folder icon in the project window to show your changes. If you replace images in the finder you might also have to do a Clean before you build your project to reflect your changed files.
This does not seem to work with html pages. But it does with javascript files and images, and probably other files as well.
Here is a project file to make it easier to understand, notice the javascript and images folders have blue icons instead of yellow. I hope it works, you might need the latest beta or something. Run this sample, if that image shows, and you can click it to get an alert, then sub-folders work.