Support pagination for values nested inside clerk/html (#428)

Co-authored-by: Martin Kavalar <martin@nextjournal.com>

Author: zampino

CHANGELOG.md

@@ -7,7 +7,7 @@ Changes can be:
 
 ## Unreleased
 
-...
+* 💫 Support pagination for values nested inside `clerk/html`
 
 ## 0.13.838 (2023-03-02)
 

notebooks/pagination.clj

@@ -73,3 +73,11 @@
 (clerk/html [:div
              [:h3 "Nesting Images inside " [:span.font-mono "clerk/html"]]
              (clerk/image "trees.png")])
+
+(clerk/html [:div
+             [:h3 "Nesting paginated collections inside " [:span.font-mono "clerk/html"]]
+             [:ul
+              [:li "A strong range: "
+               [:p [:strong {:nextjournal/value (range 30)}]]]
+              [:li "A slanted range:"
+               [:p [:em {:nextjournal/value (range 100)}]]]]])

src/nextjournal/clerk/viewer.cljc

@@ -846,6 +846,7 @@
       (merge (select-keys (->opts wrapped-value) [:!budget :store!-wrapped-value :nextjournal/budget :path]))
       (update :path (fnil conj []) path-segment)))
 
+
 (defn transform-html [{:as wrapped-value :keys [path]}]
   (let [!path-idx (atom -1)]
     (update wrapped-value
@@ -1509,6 +1510,8 @@
   (let [x (->value desc)
         viewer-name (-> desc ->viewer :name)]
     (cond (= viewer-name `elision-viewer) (with-meta '... x)
+          (= viewer-name `html-viewer) (update desc :nextjournal/value desc->values)
+          (and (vector? x) (= (first x) (inspect-fn))) {:nextjournal/value (desc->values (second x))}
           (coll? x) (into (case viewer-name
                             (nextjournal.clerk.viewer/map-viewer
                              nextjournal.clerk.viewer/table-viewer) {}
@@ -1521,22 +1524,11 @@
 #_(desc->values (present (table (mapv vector (range 30)))))
 #_(desc->values (present (with-viewer `table-viewer (normalize-table-data (repeat 60 ["Adelie" "Biscoe" 50 30 200 5000 :female])))))
 
-(defn path-to-value [path]
-  (conj (interleave path (repeat :nextjournal/value)) :nextjournal/value))
-
 (defn merge-presentations [root more elision]
-  (update-in root
-             (path-to-value (:path elision))
-             (fn [value]
-               (let [{:keys [offset path]} (-> value peek :nextjournal/value)
-                     path-from-value (conj path offset)
-                     path-from-more (or (:replace-path elision) ;; string case, TODO find a better way to unify
-                                        (-> more :nextjournal/value first :path))]
-                 (when (not= path-from-value path-from-more)
-                   (throw (ex-info "paths mismatch" {:path-from-value path-from-value :path-from-more path-from-more :root root :more more :path-to-value (path-to-value (:path more)) :value value})))
-                 (into (pop value) (:nextjournal/value more))))))
-
-
+  (clojure.walk/postwalk (fn [x] (if (some #(= elision (:nextjournal/value %)) (when (coll? x) x))
+                                   (into (pop x) (:nextjournal/value more))
+                                   x))
+                         root))
 
 (defn assign-closing-parens
   ([node] (assign-closing-parens '() node))

test/nextjournal/clerk/viewer_test.clj

@@ -77,7 +77,11 @@
 
   (testing "resolving multiple elisions"
     (let [value (reduce (fn [acc i] (vector i acc)) :fin (range 15 0 -1))]
-      (is (= value (v/desc->values (-> (v/present {:nextjournal/budget 11 :nextjournal/value value}) resolve-elision resolve-elision)))))))
+      (is (= value (v/desc->values (-> (v/present {:nextjournal/budget 11 :nextjournal/value value}) resolve-elision resolve-elision))))))
+
+  (testing "elision inside html"
+    (let [value (v/html [:div [:ul [:li {:nextjournal/value (range 30)}]]])]
+      (is (= (v/->value value) (v/->value (v/desc->values (resolve-elision (v/present value)))))))))
 
 (deftest apply-viewers
   (testing "selects number viewer"
@@ -188,6 +192,9 @@
            (v/desc->values (v/present {:nextjournal/budget 3, :nextjournal/value (range 10)}))
            (v/desc->values (v/present {:nextjournal/budget 3, :nextjournal/value (range 10)}))))))
 
+(defn path-to-value [path]
+  (conj (interleave path (repeat :nextjournal/value)) :nextjournal/value))
+
 (deftest assign-closing-parens
   (testing "closing parenthesis are moved to right-most children in the tree"
     (let [before (#'v/present* (assoc (v/ensure-wrapped-with-viewers {:a [1 '(2 3 #{4})]
@@ -196,26 +203,26 @@
 
       (is (= "}"
              (-> before
-                 (get-in (v/path-to-value [0 1 1]))
+                 (get-in (path-to-value [0 1 1]))
                  (get 2)
                  v/->viewer
                  :closing-paren)))
       (is (= ")"
              (-> before
-                 (get-in (v/path-to-value [1]))
+                 (get-in (path-to-value [1]))
                  (get 1)
                  v/->viewer
                  :closing-paren)))
 
       (is (= '( "}" ")" "]")
              (-> after
-                 (get-in (v/path-to-value [0 1 1]))
+                 (get-in (path-to-value [0 1 1]))
                  (get 2)
                  v/->viewer
                  :closing-paren)))
       (is (= '(")" "}")
              (-> after
-                 (get-in (v/path-to-value [1]))
+                 (get-in (path-to-value [1]))
                  (get 1)
                  v/->viewer
                  :closing-paren))))))