abi output formatting

lib/abi.js

@@ -8,11 +8,17 @@ var findIndex = function (array, callback) {
     return end ? i - 1 : -1;
 };
 
+var findMethodIndex = function (json, methodName) {
+    return findIndex(json, function (method) {
+        return method.name === methodName;
+    });
+};
+
 var padLeft = function (number, n) {
     return (new Array(n * 2 - number.toString().length + 1)).join("0") + number;
 };
 
-var setupTypes = function () {
+var setupInputTypes = function () {
     var prefixedType = function (prefix) {
         return function (type, value) {
             var expected = prefix;
@@ -25,32 +31,34 @@ var setupTypes = function () {
         };
     };
 
-    var namedType = function (name, padding) {
+    var namedType = function (name, padding, formatter) {
         return function (type, value) {
             if (type !== name) {
                 return false; 
             }
 
-            return padLeft(value, padding);
+            return padLeft(formatter ? value : formatter(value), padding);
         };
     };
 
+    var formatBool = function (value) {
+        return value ? '1' : '0';
+    };
+
     return [
         prefixedType('uint'),
         prefixedType('int'),
         namedType('address', 20),
-        namedType('bool', 1),
+        namedType('bool', 1, formatBool),
     ];
 };
 
-var types = setupTypes();
+var inputTypes = setupInputTypes();
 
-var toBytes = function (json, methodName, params) {
+var toAbiInput = function (json, methodName, params) {
     var bytes = "";
-    var index = findIndex(json, function (method) {
-        return method.name === methodName;
-    });
-
+    var index = findMethodIndex(json, methodName);
+    
     if (index === -1) {
         return;
     }
@@ -62,8 +70,8 @@ var toBytes = function (json, methodName, params) {
     
     for (var i = 0; i < method.inputs.length; i++) {
         var found = false;
-        for (var j = 0; j < types.length && !found; j++) {
-            found = types[j](method.inputs[i].type, params[i]);
+        for (var j = 0; j < inputTypes.length && !found; j++) {
+            found = inputTypes[j](method.inputs[i].type, params[i]);
         }
         if (!found) {
             console.error('unsupported json type: ' + method.inputs[i].type);
@@ -73,7 +81,75 @@ var toBytes = function (json, methodName, params) {
     return bytes;
 };
 
-module.exports = {
-    toBytes: toBytes
+var setupOutputTypes = function () {
+    var prefixedType = function (prefix) {
+        return function (type) {
+            var expected = prefix;
+            if (type.indexOf(expected) !== 0) {
+                return -1;
+            }
+            
+            var padding = parseInt(type.slice(expected.length)) / 8;
+            return padding * 2;
+        };
+    };
+
+    var namedType = function (name, padding) {
+        return function (type) {
+            return name === type ? padding * 2: -1;
+        };
+    };
+
+    var formatInt = function (value) {
+        return parseInt(value, 16);
+    };
+
+    var formatBool = function (value) {
+        return value === '1' ? true : false;
+    };
+
+    return [
+    { padding: prefixedType('uint'), format: formatInt },
+    { padding: prefixedType('int'), format: formatInt },
+    { padding: namedType('address', 20) },
+    { padding: namedType('bool', 1), format: formatBool }
+    ];
+};
+
+var outputTypes = setupOutputTypes();
+
+var fromAbiOutput = function (json, methodName, output) {
+    var index = findMethodIndex(json, methodName);
+
+    if (index === -1) {
+        return;
+    }
+    
+    output = output.slice(2);
+
+    var result = [];
+    var method = json[index];
+    for (var i = 0; i < method.outputs.length; i++) {
+        var padding = -1;
+        for (var j = 0; j < outputTypes.length && padding === -1; j++) {
+            padding = outputTypes[j].padding(method.outputs[i].type);
+        }
+
+        if (padding === -1) {
+            // not found output parsing
+            continue;
+        }
+        var res = output.slice(0, padding);
+        var formatter = outputTypes[j - 1].format;
+        result.push(formatter ? formatter(res): res);
+        output = output.slice(padding);
+    }
+
+    return result;
+};
+
+module.exports = {
+    toAbiInput: toAbiInput,
+    fromAbiOutput: fromAbiOutput
 };