I wrote an GUI-based ASOC application on Xcode which save/load a custom document.
I found Xcode has QuickLook plugin build target. It generates a Objective-C based template.
Github hosts many sample of QuickLook. They are written in various languages.
Can I write QuickLook plugin with AppleScript?
I don’t think so. The plugin API is C-based, not Objective-C based. It’s also an area where performance is paramount, so it probably wouldn’t be a good idea anyhow.
Finally, I made a QuickLook independent preview system.
My app write out preview image file and embed the document information by using steganography technology.
Now I can export information embedded image file by PNG format. A friend of mine told an idea.
He said “optical readable data embedding” by using QR code over preview image.
By using several QR codes, I can embed whole document internal information.