a nice wrapper to handle rhino from clojure
marianoguerra
the java api for rhino is not really nice
go to clojars page for instructions:
https://clojars.org/org.marianoguerra/clj-rhino
you can see the tests for some usage, here are some REPL examples:
user=> (require '[clj-rhino :as js])
nil
user=> (def sc (js/new-safe-scope))
#'user/sc
user=> (js/eval sc "1 + 1")
2
user=> (js/eval sc "a = 1 + 1")
2
user=> (js/get sc "a")
2
user=> (js/get sc "b")
#<UniqueTag org.mozilla.javascript.UniqueTag@172897f: NOT_FOUND>
user=> (js/undefined? (js/get sc "b"))
true
user=> (js/get sc "b" :w00t?)
:w00t?
user=> (js/defined? (js/get sc "b"))
false
user=> (js/set! sc "b" 42)
nil
user=> (js/defined? (js/get sc "b"))
true
user=> (js/get sc "b" :w00t?)
42
user=> (js/eval sc "a = {name: 'spongebob'}")
#<NativeObject [object Object]>
user=> (js/get-in sc [:a :name])
"spongebob"
user=> (js/get-in sc [:a :age])
#<UniqueTag org.mozilla.javascript.UniqueTag@172897f: NOT_FOUND>
user=> (js/get-in sc [:a :age] :dont-know)
:dont-know
user=> (def compiled-fun (js/compile-function sc "function (a, b) { return a + b; }" :filename "foo.js"))
#'user/compiled-fun
user=> (js/set! sc "add" compiled-fun)
nil
user=> (js/eval sc "add(1, 3)")
4.0
handy convertions:
user=> (def get-field (js/compile-function sc "function getField(obj, field) { return obj[field]; }"))
#'user/get-field
user=> (js/set! sc "getField" get-field)
nil
user=> (js/set! sc "obj" (js/with-context #(js/to-js {:name "spongebob"} sc %)))
nil
user=> (js/eval sc "getField(obj, 'name')")
"spongebob"
user=> (js/eval sc "o = {name: 'spongebob', friends: ['patrick', 'sandy']};")
#<NativeObject [object Object]>
user=> (js/from-js (js/eval sc "o = {name: 'spongebob', friends: ['patrick', 'sandy']};"))
{:friends ["patrick" "sandy"], :name "spongebob"}
exposing clojure functions to rhino:
user=> (require '[clj-rhino :as js]) nil user=> (defn add [ctx scope this [a b]] (+ a b)) #'user/add user=> (def scope (js/new-safe-scope)) #'user/scope user=> (js/set! scope "add" (js/make-fn add)) nil user=> (js/eval scope "add(1, 2)") 3.0
exposing objects with functions:
user=> (require '[clj-rhino :as js])
nil
user=> (defn add [ctx scope this [a b]] (+ a b))
#'user/add
user=> (defn mul [ctx scope this [a b]] (* a b))
#'user/mul
user=> (def scope (js/new-safe-scope))
#'user/scope
user=> (def api {:add add :multiply mul})
#'user/api
user=> (js/with-context (fn [ctx]
#_=> (js/set! scope "api" (js/to-js api scope ctx))
#_=> (js/eval scope "api.add(1, 2) + api.multiply(2, 3)")))
9.0
or if you don't need the internal parameters:
(js/with-context
(fn [ctx]
(let [scope (js/new-safe-scope)
add (fn [a b] (+ a b))]
(js/set! scope "add" (js/wrap-plain-fn add))
(js/eval scope "add(1, 2)") 3.0)))
execute code with timeout:
(def scope (js/new-safe-scope)) (js/eval-timeout scope "while (true);" 1000) ; will throw a Error exception
call function with timeout:
user=> (def f (js/compile-function scope "function () { while(true); }"))
#'user/f
user=> (js/call-timeout scope f 1000)
TimeOutError
org.marianoguerra.rhino.TimedContextFactory.observeInstructionCount
(TimedContextFactory.java:47)
; function that doesn't timeout
user=> (def f1 (js/compile-function scope "function (a, b) { return a +
b; }"))
#'user/f1
user=> (js/call-timeout scope f1 1000 1 3)
4.0
it seems the clojure people under this circumstances say something like:
Copyright © 2013 marianoguerra
Distributed under the Eclipse Public License, the same as Clojure.
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