So, bless Helix, this works (mkx rn/Button :name :counter42 :counter (cI 3) title (cF (str "Counter = " (mget me :counter))) :disabled (cF (not (mget (mxu! me :counting?) :value))) :jsx {:title (mget me :title) :disabled (mget me :disabled) :color "black" :onPress #(mswap! me :counter inc)}) That is a reactive matrix object with reactive properties :title, :counter, and :disabled. Not shown is the rn/Switch named :counting? that disables :counter42. :jsx is a cruel pun on RN. The associated map gets fed to the Helix $ macro in the props position to create the element. Works great, but the dream would be: :jsx (with-props [:title :disabled] :color "black" :onPress #(mswap! me :counter inc)) I need the macro so I can emit code that captures me (akin to self or this), an anaphor established by another Matrix macro CF that emits the code to build the element. Unfortunately with-props conflicts with the $ macro's handling of the attributes map (as nicely documented! Along with the :& workaround!!): :jsx {:& (with-props :title :disabled) :color "black" :onPress #(mswap! me :counter inc))} Not shabby at all, esp. since the :& was tolerated in the first position. 🙂 All of this an incredibly long way of asking if I could have made the dream solution ^^^ work. Maybe a cleverly positioned clj->js? I did try that, but perhaps I had it at the wrong stage of macro expansion.

perhaps pass the whole :jsx map into :&?

I'm v happy to hear that the documentation was clear to you about that btw. I think that's one of the biggest confusions people have onboarding to helix (static props + using :&)

"pass the whole :jsx map into :&?"?! Diabolical. I like it. brb...

Heh-heh, it works: :jsx {:& (with-props [:title :disabled] :color "cyan" :onPress #(when (mget (mxu! me :counting?) :value) (mswap! me :counter inc)))} It's a little busy, tho. Perhaps some more macrology can obviate the need for :jsx. Thanks for the idea. 🙏