From 8b59d1509b76dc306a37dee3ecd0ad4b99cf0d56 Mon Sep 17 00:00:00 2001
From: Dan Holmsand <holmsand@gmail.com>
Date: Fri, 14 Mar 2014 10:27:49 +0100
Subject: [PATCH] Add macros for more convenient javascript interop

---
 src/reagent/interop.clj  | 40 ++++++++++++++++++++++++++++++++
 src/reagent/interop.cljs |  3 +++
 test/testinterop.cljs    | 49 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 src/reagent/interop.clj
 create mode 100644 src/reagent/interop.cljs
 create mode 100644 test/testinterop.cljs

diff --git a/src/reagent/interop.clj b/src/reagent/interop.clj
new file mode 100644
index 0000000..6377932
--- /dev/null
+++ b/src/reagent/interop.clj
@@ -0,0 +1,40 @@
+(ns reagent.interop)
+
+(defn- js-call [f args]
+  (let [argstr (->> (repeat (count args) "~{}")
+                    (interpose ",")
+                    (apply str))]
+    (list* 'js* (str "~{}(" argstr ")") f args)))
+
+(defn- from-keyword [k]
+  (if (keyword? k)
+    (name k)
+    k))
+
+(defn- get-names [k]
+  (->> (if (vector? k) k [k])
+       (map from-keyword)))
+
+(defmacro jget
+  [o k]
+  `(aget ~o ~@(get-names k)))
+
+(defmacro jset
+  [o k v]
+  `(aset ~o ~@(get-names k) ~v))
+
+(defmacro jcall
+  [o k & args]
+  (let [names (get-names k)
+        f (if (empty? names)
+            o
+            (list* 'aget o names))]
+    (js-call f args)))
+
+(defmacro jval
+  [s]
+  (assert (keyword? s))
+  (let [sym (symbol "js" (name s))]
+    `(when (clojure.core/exists? ~sym)
+       ~sym)))
+
diff --git a/src/reagent/interop.cljs b/src/reagent/interop.cljs
new file mode 100644
index 0000000..d5a872f
--- /dev/null
+++ b/src/reagent/interop.cljs
@@ -0,0 +1,3 @@
+(ns reagent.interop)
+
+;; Empty file, to allow require with :refer-macros
diff --git a/test/testinterop.cljs b/test/testinterop.cljs
new file mode 100644
index 0000000..802386d
--- /dev/null
+++ b/test/testinterop.cljs
@@ -0,0 +1,49 @@
+(ns testinterop
+  (:require [cemerick.cljs.test :as t :refer-macros [is deftest]]
+            [reagent.debug :refer-macros [dbg]]
+            [reagent.interop :refer-macros [jget jset jcall jval]]))
+
+(deftest interop-basic
+  (let [o #js {:foo "foo"
+               :foobar #js {:bar "bar"}}]
+    (is (= "foo" (jget o :foo)))
+    (is (= "foo" (jget o [:foo])))
+    (is (= "bar" (jget o [:foobar :bar])))
+
+    (jset o :foo "foo1")
+    (is (= "foo1" (jget o :foo)))
+
+    (jset o [:foo] "foo2")
+    (is (= "foo2" (jget o :foo)))
+
+    (jset o [:foobar :bar] "bar1")
+    (is (= "bar1" (jget o [:foobar :bar])))))
+
+(deftest interop-call
+  (let [o #js {:bar "bar1"
+               :foo (fn [x]
+                      (this-as this
+                               (str x (jget this :bar))))}
+        o2 #js {:o o}]
+    (is (= "ybar1" (jcall o :foo "y")))
+    (is (= "xxbar1" (jcall o2 [:o :foo] "xx")))
+    (is (= "abar1" (-> o2
+                       (jget [:o :foo])
+                       (jcall [] "a"))))
+    
+    (is (= "bar1" (jcall o :foo)))
+    (is (= "bar1" (jcall o [:foo])))
+    (is (= "bar1" (jcall o2 [:o :foo])))
+
+    (jset o :bar "bar2")
+    (is (= "bar2" (jcall o :foo)))
+
+    (is (= "1bar2" (jcall (jget o :foo)
+                          :call o 1)))
+
+    (is (= "yy" (jcall identity [] "yy")))))
+
+(deftest interop-val
+  (set! js/someGlobal "foo")
+  (is (= "foo" (jval :someGlobal)))
+  (is (nil? (jval :nonExistingGlobal))))