the form is pretty good now.

src/cljs/auto_ap/forms.cljs

@@ -59,6 +59,22 @@
     db
     (partition 2 path-pairs))))
 
+(defn change-handler [form customize-fn]
+  (fn  [db [_ & path-pairs]]
+    (println "CHA" form path-pairs)
+    (reduce
+     (fn [db [path value]]
+       (println "PATH" path "VALUE" value)
+       (let [updated (assoc-in db (into [::forms form :data] path) value)]
+         (reduce 
+          (fn [updated [path value ]]
+            (println "custom PATH" path "custom VALUE" value)
+            (assoc-in updated (into [::forms form :data] path) value))
+          updated
+          (partition 2 (customize-fn (get-in updated [::forms form :data]) path value)))))
+     db
+     (partition 2 path-pairs))))
+
 (re-frame/reg-event-db
  ::save-error
  (fn  [db [_ form result]]

src/cljs/auto_ap/views/pages/transactions/form.cljs

@@ -53,21 +53,19 @@
                            (assoc :potential-payment-matches potential-payment-matches)
                            (update :accounts expense-accounts-field/from-graphql (:amount which) locations))))))
 
-(re-frame/reg-event-fx
+(re-frame/reg-event-db
  ::changed
- [(forms/in-form ::form)]
- (fn  [{{:keys [data]} :db} [_ field value]]
-   (let [locations @(re-frame/subscribe [::subs/locations-for-client (:id (:client data))])]
-     (if (and (= [:vendor] field)
-              value
-              (expense-accounts-field/can-replace-with-default? (:accounts data)))
-       {:dispatch [::forms/change ::form
-                   field value
-                   [:accounts] (expense-accounts-field/default-account (:accounts data)
-                                                                       @(re-frame/subscribe [::subs/vendor-default-account value])
-                                                                       (:amount data)
-                                                                       locations)]}
-       {:dispatch [::forms/change ::form field value]}))))
+ (forms/change-handler ::form
+  (fn  [data field value]
+    (let [locations @(re-frame/subscribe [::subs/locations-for-client (:id (:client data))])]
+      (if (and (= [:vendor] field)
+               value
+               (expense-accounts-field/can-replace-with-default? (:accounts data)))
+        [[:accounts] (expense-accounts-field/default-account (:accounts data)
+                                                             @(re-frame/subscribe [::subs/vendor-default-account value])
+                                                             (:amount data)
+                                                             locations)]
+        [])))))
 
 (re-frame/reg-event-fx
  ::saving