Merge pull request #8 from martinklepsch/instance-maker

add function to create web3 instance from injected web3

README.md

@@ -57,7 +57,10 @@ Some functions in `cljs-web3.core` don't really need a web3 instance, even thoug
 #### Extra functions for a better life
 These are a few extra functions, which you won't find in the Web3 API:
 ```clojure
-;; Create web3 instance
+;; Create web3 instance from injected web3 (Mist / Metamask)
+(web3/web3)
+
+;; Create web3 instance from HTTP provider
 (web3/create-web3 "http://localhost:8545/")
 
 ;; Deploy new contract

src/cljs_web3/core.cljs

@@ -15,8 +15,8 @@
      (create-web3 \"http://localhost:8545/\"))`
 
   The Web3 JavaScript object is provided on the browser window."
-  (:require [cljs-web3.utils :as u :refer [js-apply js-prototype-apply]]))
-
+  (:require [cljs-web3.utils :as u :refer [js-apply js-prototype-apply]]
+            [goog.object]))
 
 (def version-api
   "Returns a string representing the Ethereum js api version.
@@ -386,6 +386,12 @@
   [web3]
   (aget web3 "currentProvider"))
 
+(defn web3
+  "Return the web3 instance injected via Mist or Metamask"
+  []
+  (new (goog.object/getValueByKeys js/window "web3" "constructor")
+       (current-provider
+        (goog.object/get js/window "web3"))))
 
 ;;; Providers