FWIW, I did have a go at creating basic Custom Compendium functionality, and it can be done. At least in terms of saving a repeating section entry, so it can later be dragged to a new sheet - for the majority of sheets, this would at least cover items, weapons, spells, traits etc. This is a temp Firefox browser extension, and obviously I had to use a bunch of hacks that wouldn't be necessary for someone actually working on the VTT code. There were a bunch of system-specific hurdles, but they're certainly not insurmountable. Click for action: Obviously a native version would hook straight into the right side bar, instead of the floating frame I had to build. Fundamentally, all this is doing is saving every attribute in the repeating row after stripping out whatever isn't needed (row id etc.). Dropping it onto a sheet just rolls a new id and creates a new row with the saved data. I'd imagine the sheet author could use the sheet settings JSON to nominate the attribute names in each repeating section which need to go in the Compendium list entry for display purposes, e.g. : // Other character sheet settings customCompendium: { enabled: true, repeatingSections: [ { section: 'spells', title: 'spellname', // the Title is the listed name in the compendium in the right side bar description: 'spelldesc', // This is shown when the Compendium entry is clicked }, { section: 'inventory', title: 'itemname', description: 'itemdesc' } ] } A quick and dirty way to ensure an item will at least have a readable name and description in the right sidebar. I'd imagine the current summernote editor could be used, much like a handout, to pretty up the Compendium entry further - perhaps a separate frame so the repeating_spells_$rowid_spelldesc entry isn't being edited. The other aspect I had in my attempt was Collections - this was for things like a custom subclass. It allows the GM to save links to other Compendium entries, split up by level (this was 5e specific, but that's another aspect that can face the sheet authors). This allows you to, for example, create a SillyWizard subclass, and save whatever spells / items / traits (any repeating section entry really) you would like under each relevant character level for that class. The player can then drag the subclass entry onto their sheet, and select which character levels they'd like to apply to their sheet. I don't have an action shot of that but it was all drag & drop again: So... if I can do it, real coders can definitely do it :) This direction splits the custom compendium away from the real compendium - the two don't really interact. I feel like this is the most realistic direction to go in, considering how unsuitable the backend of the real Compendium is for user-facing functionality, and attempting to get custom content to interact properly with published content and.... loads of problems. Anyways, I abandoned working on this a while ago since I'm not actively playing anymore, and would probably completely rewrite it if I picked it up again. But it worked! You can do it Roll20, you can do it!
