improved contracts interface

lib/abi.js

@@ -1,3 +1,24 @@
+/*
+    This file is part of ethereum.js.
+
+    ethereum.js is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ethereum.js is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with ethereum.js.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file abi.js
+ * @authors:
+ *   Marek Kotewicz <marek@ethdev.com>
+ * @date 2014
+ */
 
 var findIndex = function (array, callback) {
     var end = false;
@@ -71,7 +92,8 @@ var toAbiInput = function (json, methodName, params) {
     for (var i = 0; i < method.inputs.length; i++) {
         var found = false;
         for (var j = 0; j < inputTypes.length && !found; j++) {
-            found = inputTypes[j](method.inputs[i].type, params[i]);
+            var val = parseInt(params[i]).toString(16);
+            found = inputTypes[j](method.inputs[i].type, val);
         }
         if (!found) {
             console.error('unsupported json type: ' + method.inputs[i].type);
@@ -148,17 +170,31 @@ var fromAbiOutput = function (json, methodName, output) {
     return result;
 };
 
-var load = function (json) {
-    var contract = {};
+var inputParser = function (json) {
+    var parser = {};
     json.forEach(function (method) {
-        contract[method.name] = function () {
+        parser[method.name] = function () {
             var params = Array.prototype.slice.call(arguments);
             return toAbiInput(json, method.name, params);
         };
     });
 
-    return contract;
+    return parser;
 };
 
-module.exports = load;
+var outputParser = function (json) {
+    var parser = {};
+    json.forEach(function (method) {
+        parser[method.name] = function (output) {
+            return fromAbiOutput(json, method.name, output);
+        };
+    });
+
+    return parser;
+};
+
+module.exports = {
+    inputParser: inputParser,
+    outputParser: outputParser
+};
 

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;