om - data not updating after ajax call

Question

I have the following code and I think I am doing something fundamentally wrong.

(defn world-view [data owner opts]
  (reify
    om/IInitState
      (init-state [_]
        (om/update! data #(assoc % :world vec)))
    om/IWillMount
      (will-mount [_]
        (go (let [world (<! (get-world (:dimensions opts)))]
              (log (get-in world [9 9]))
              (om/update! data #(assoc % :world world)))))
    om/IRender
      (render [this]
        (log (get :world data))
        (apply dom/table nil
          (om/build-all row (:world data))))))

I am making a remote ajax call in om/IWillMount like this:

om/IWillMount
  (will-mount [_]
    (go (let [world (<! (get-world (:dimensions opts)))]
          (log (get-in world [9 9]))
          (om/update! data #(assoc % :world world)))))

I am expecting a 2d vector back from the remote call and this works because I can log elements of the array with

(log (get-in world [9 9]))

I am then using om/update to update the data structure.

But when render is called, the data does not appear to be updated, I can test this by trying to log the data structure

log (get :world data))

This logs nothing.

I can't see what I am doing wrong or why the data structure has not been updated.

Answer 1

om/update! sets the cursor to the given value, so you're basically assigning a function to your cursor. I believe you should use om/transact! instead.