Recently I’ve been building an adventure game engine that works as a mix between the SNES’ Clock Tower game and Phoenix Wright. In my last game, Canvasser, all the dialogue was hard-coded in the game, and it became kind of nightmarish to work with at times. In this adventure game, which will have more dialogue and other writers working on it, I knew I had to make a scenario editor to make all our lives easier.
Saving/Loading is a bit wonky, because in JS you can only download files, not save them (as far as I know). I’m considering using a library that embeds a flash file into the page to allow for traditional file saving.
Overall I’d strongly recommend this approach for proprietary scenario editors. It gets the job done, and is flexible enough without giving you too many options.