Compute doc URL on the JVM (#284)

Fixes behaviour of `clerk/doc-url` in static app. A regression introduced when by dropping EDN encoding of results in #273.

notebooks/viewers/html.clj

@@ -1,8 +1,22 @@
 ;; # HTML & Hiccup 🧙‍♀️
-(ns html (:require [nextjournal.clerk :as clerk]))
+(ns viewers.html (:require [nextjournal.clerk :as clerk]))
 
 (clerk/html "<h3>Ohai, HTML! 👋</h3>")
 
 (clerk/html [:h3 "We "
              [:i "strongly"]
              " prefer hiccup, don't we? ✨"])
+
+;; Linking to notebooks
+
+(clerk/html
+ [:div
+  "Go to "
+  [:a.text-lg {:href (clerk/doc-url "notebooks/viewers/image.clj")} "images"]
+  " notebook."])
+
+(clerk/with-viewer
+ '(fn [_ _] [:div
+             "Go to "
+             [:a.text-lg {:href (v/doc-url "notebooks/viewers/image.clj")} "images"]
+             " notebook."]) nil)

resources/viewer-js-hash

@@ -1 +1 @@
-38F71uHxJsdbeuJsMnSfkow4eTQ2
+462ZVi7ZTvDpYGQ3GJkyBDP76cJ9

src/nextjournal/clerk.clj

@@ -326,8 +326,7 @@
   "Experimental notebook viewer. You probably should not use this."
   (partial with-viewer (:name v/notebook-viewer)))
 
-(defn doc-url [path]
-  (v/->viewer-eval (list 'v/doc-url path)))
+(defn doc-url [path] (v/doc-url path))
 
 (defmacro example
   "Evaluates the expressions in `body` showing code next to results in Clerk.

src/nextjournal/clerk/builder.clj

@@ -115,12 +115,21 @@
            index (assoc :index (str index)))))
 
 #_(process-build-opts {:index 'book.clj})
+(defn build-path->url [{:as opts :keys [bundle?]} docs]
+  (into {}
+        (map (comp (juxt identity #(cond-> (->> % (view/map-index opts) strip-index) (not bundle?) ->html-extension))
+                   :file))
+        docs))
+#_(build-path->url {:bundle? false} [{:file "notebooks/foo.clj"} {:file "index.clj"}])
+#_(build-path->url {:bundle? true}  [{:file "notebooks/foo.clj"} {:file "index.clj"}])
 
 (defn build-static-app-opts [{:as opts :keys [bundle? out-path browse? index]} docs]
-  (let [paths (mapv :file docs)
-        path->doc (into {} (map (juxt :file :viewer)) docs)
-        path->url (into {} (map (juxt identity #(cond-> (->> % (view/map-index opts) strip-index) (not bundle?) ->html-extension))) paths)]
-    (assoc opts :bundle? bundle? :path->doc path->doc :paths (vec (keys path->doc)) :path->url path->url)))
+  (let [path->doc (into {} (map (juxt :file :viewer)) docs)]
+    (assoc opts
+           :bundle? bundle?
+           :path->doc path->doc
+           :paths (vec (keys path->doc))
+           :path->url (build-path->url opts docs))))
 
 (defn ssr!
   "Shells out to node to generate server-side-rendered html."
@@ -239,7 +248,7 @@
            "/css/viewer.css" (viewer/store+get-cas-url! (assoc opts :ext "css") (fs/read-all-bytes tw-output)))
     (fs/delete-tree tw-folder)))
 
-(defn build-static-app! [opts]
+(defn build-static-app! [{:as opts :keys [bundle?]}]
   (let [{:as opts :keys [download-cache-fn upload-cache-fn report-fn compile-css?]}
         (process-build-opts opts)
         {:keys [expanded-paths error]} (try {:expanded-paths (expand-paths opts)}
@@ -267,11 +276,17 @@
             (report-fn {:stage :downloading-cache})
             (let [{duration :time-ms} (eval/time-ms (download-cache-fn state))]
               (report-fn {:stage :done :duration duration})))
-        state (mapv (fn [doc idx]
+        state (mapv (fn [{:as doc :keys [file]} idx]
                       (report-fn {:stage :building :doc doc :idx idx})
                       (let [{result :result duration :time-ms} (eval/time-ms
                                                                 (try
-                                                                  (let [doc (eval/eval-analyzed-doc doc)]
+                                                                  (let [doc (binding [viewer/doc-url
+                                                                                      (fn [path]
+                                                                                        (let [url (get (build-path->url opts state) path)]
+                                                                                          (if bundle?
+                                                                                            (str "#/" url)
+                                                                                            (str (viewer/relative-root-prefix-from file) url))))]
+                                                                              (eval/eval-analyzed-doc doc))]
                                                                     (assoc doc :viewer (view/doc->viewer (assoc opts :inline-results? true) doc)))
                                                                   (catch Exception e
                                                                     {:error e})))]

src/nextjournal/clerk/viewer.cljc

@@ -1365,8 +1365,8 @@
 (def tex          (partial with-viewer katex-viewer))
 (def notebook     (partial with-viewer (:name notebook-viewer)))
 (def code         (partial with-viewer code-viewer))
-(defn doc-url [path]
-  (->viewer-eval (list 'nextjournal.clerk.render/doc-url path)))
+
+(defn ^:dynamic doc-url [path] (str "#/" path))
 
 (defn hide-result
   "Deprecated, please put ^{:nextjournal.clerk/visibility {:result :hide}} metadata on the form instead."