A more complete Reagent config, including with-let

src/scittle/reagent.cljs

@@ -1,15 +1,106 @@
 (ns scittle.reagent
   (:require [reagent.core :as r]
+            [reagent.debug :as d :refer-macros [dev?]]
             [reagent.dom :as rdom]
+            [reagent.ratom :as ratom]
             [sci.core :as sci]
             [scittle.core :as scittle]))
 
+;; The with-let macro from reagent.core. The only change is that the
+;; interop/unchecked-aget+set were replaced by aget and aset.
+(defn ^:macro with-let [_ _ bindings & body]
+  (assert (vector? bindings)
+          (str "with-let bindings must be a vector, not "
+               (pr-str bindings)))
+  (let [v (gensym "with-let")
+        k (keyword v)
+        init (gensym "init")
+        ;; V is a reaction, which holds a JS array.
+        ;; If the array is empty, initialize values and store to the
+        ;; array, using binding index % 2 to access the array.
+        ;; After init, the bindings are just bound to the values in the array.
+        bs (into [init `(zero? (alength ~v))]
+                 (map-indexed (fn [i x]
+                                (if (even? i)
+                                  x
+                                  (let [j (quot i 2)]
+                                    ;; Issue 525
+                                    ;; If binding value is not yet set,
+                                    ;; try setting it again. This should
+                                    ;; also throw errors for each render
+                                    ;; and prevent the body being called
+                                    ;; if bindings throw errors.
+                                    `(if (or ~init
+                                             (not (.hasOwnProperty ~v ~j)))
+                                       (aset ~v ~j ~x)
+                                       (aget ~v ~j)))))
+                              bindings))
+        [forms destroy] (let [fin (last body)]
+                          (if (and (list? fin)
+                                   (= 'finally (first fin)))
+                            [(butlast body) `(fn [] ~@(rest fin))]
+                            [body nil]))
+        add-destroy (when destroy
+                      (list
+                       `(let [destroy# ~destroy]
+                          (if (reagent.ratom/reactive?)
+                            (when (nil? (.-destroy ~v))
+                              (set! (.-destroy ~v) destroy#))
+                            (destroy#)))))
+        asserting (dev?) #_(if *assert* true false)
+        res (gensym "res")]
+    `(let [~v (reagent.ratom/with-let-values ~k)]
+       ~(when asserting
+          `(when-some [c# (reagent.ratom/-ratom-context)]
+             (when (== (.-generation ~v) (.-ratomGeneration c#))
+               (d/error "Warning: The same with-let is being used more "
+                        "than once in the same reactive context."))
+             (set! (.-generation ~v) (.-ratomGeneration c#))))
+       (let ~(into bs [res `(do ~@forms)])
+         ~@add-destroy
+         ~res))))
+
 (def rns (sci/create-ns 'reagent.core nil))
 
 (def reagent-namespace
   {'atom (sci/copy-var r/atom rns)
    'as-element (sci/copy-var r/as-element rns)
-   'create-class (sci/copy-var r/create-class rns)})
+   'with-let (sci/copy-var with-let rns)
+   'cursor (sci/copy-var r/cursor rns)
+   'create-class (sci/copy-var r/create-class rns)
+   'create-compiler (sci/copy-var r/create-compiler rns)})
+
+(def rtmns (sci/create-ns 'reagent.ratom nil))
+
+(defn -ratom-context
+  "Read-only access to the ratom context."
+  []
+  ratom/*ratom-context*)
+
+(def reagent-ratom-namespace
+  {'with-let-values (sci/copy-var ratom/with-let-values rtmns)
+   'reactive? (sci/copy-var ratom/reactive? rtmns)
+   '-ratom-context (sci/copy-var -ratom-context rtmns)})
+
+(def rdbgns (sci/create-ns 'reagent.debug nil))
+
+(defn -tracking? []
+  reagent.debug/tracking)
+
+(defn ^:macro error
+  "Print with console.error."
+  [_ _ & forms]
+  (when *assert*
+    `(when (some? js/console)
+       (.error (if (reagent.debug/-tracking?)
+                 reagent.debug/track-console
+                 js/console)
+               (str ~@forms)))))
+
+(def reagent-debug-namespace
+  {'error (sci/copy-var error rdbgns)
+   '-tracking? (sci/copy-var -tracking? rdbgns)
+   'track-console (sci/copy-var d/track-console rdbgns)})
 
 (def rdns (sci/create-ns 'reagent.dom nil))
 
@@ -19,4 +110,6 @@
 (scittle/register-plugin!
  ::reagent
  {:namespaces {'reagent.core reagent-namespace
-               'reagent.dom reagent-dom-namespace}})
+               'reagent.dom reagent-dom-namespace
+               'reagent.ratom reagent-ratom-namespace
+               'reagent.debug reagent-debug-namespace}})