improved contracts interface

lib/main.js

@@ -22,6 +22,8 @@
  * @date 2014
  */
 
+var abi = require('./abi');
+
 function flattenPromise (obj) {
     if (obj instanceof Promise) {
         return Promise.resolve(obj);
@@ -292,9 +294,8 @@ var web3 = {
     }
 };
 
-var eth = web3.eth;
-setupMethods(eth, ethMethods());
-setupProperties(eth, ethProperties());
+setupMethods(web3.eth, ethMethods());
+setupProperties(web3.eth, ethProperties());
 setupMethods(web3.db, dbMethods());
 setupMethods(web3.shh, shhMethods());
 
@@ -454,5 +455,40 @@ function messageHandler(data) {
     }
 }
 
+web3.contract = function (address, desc) {
+    var inputParser = abi.inputParser(desc);
+    var outputParser = abi.outputParser(desc);
+
+    var contract = {};
+
+    desc.forEach(function (method) {
+        contract[method.name] = function () {
+            var params = Array.prototype.slice.call(arguments);
+            var parsed = inputParser[method.name].apply(null, params);
+
+            var onSuccess = function (result) {
+                return outputParser[method.name](result);
+            };
+
+            return {
+                call: function (extra) {
+                    extra = extra || {};
+                    extra.to = address;
+                    extra.data = parsed;
+                    return web3.eth.call(extra).then(onSuccess);
+                },
+                transact: function (extra) {
+                    extra = extra || {};
+                    extra.to = address;
+                    extra.data = parsed;
+                    return web3.eth.transact(extra).then(onSuccess);
+                }
+            };
+        };
+    });
+         
+    return contract;
+};
+
 module.exports = web3;