Emitting Hiccup controls from CLJ that call CLJS functions

Question

It seems like this should be simple, and I thought it was... until I switched from running Figwheel to running a JAR file and it stopped working.

The issue can be reduced to a pretty simple example:

Make a new app called "buttontest" using the Leiningen "Reagent" template.

Add some script to core.cljs, right below the "ns" declaration:

(defn greet [] (js/alert "Hi!"))

Add a static button in handler.clj:

(defn loading-page [] (html5 (head) 
 [:body {:class "body-container"} mount-target
  ;v v v INSERTED THIS
  [:button {:onclick "buttontest.core.greet()"} "Say Hello"]
  ;^ ^ ^
  (include-js "/js/app.js")]))

Do a "lein cljsbuild once" and a "lein figwheel." Browse to the site. The "Say Hello" button will trigger an alert when clicked.

Back in the shell, do a "lein uberjar" and run the resultant .JAR file using Java. Browse to the site. The "Say Hello" button will do nothing when clicked. The console shows "buttontest is undefined."

I've tried various things (tinkering with / removing the namespace qualification in the "onclick" attribute, manually including other .JS files, etc.) without luck. I feel like I'm missing something obvious.

Any ideas? Thanks.

You're using hiccup to generate the html? What does that look like? — Alan Thompson
@AlanThompson It's pretty clean. I'm using Reitit, so I construct a big data structure that defines all my routes in handler.clj. In this data structure, there's a spot for a handler function for each route. Each handler returns a map whose members are the headers, the session, a few other miscellaneous things, and the body of the response page. This body can be a hook for Reagent to hang stuff on, but it doesn't have to be. It's perfectly fine to return a map with a member like ':body (html5 (head)[:body [:h1 "Hello, World"]])'. — user1172763

Nico Schneider Nico Schneider · Accepted Answer · 2019-01-09T10:16:15

Try giving your greet function the export meta flag:

(defn ^:export greet ...)

I imagine :advanced compilation optimizations mangles the namespace/function name, and :export prohibits that (or something like this).

Emitting Hiccup controls from CLJ that call CLJS functions

1 Answers