Adding transformers

lib/axios.js

@@ -2,7 +2,9 @@ var Promise = require('es6-promise').Promise;
 
 function axios(options) {
   options = merge({
-    method: 'get'
+    method: 'get',
+    transformRequest: defaults.transformRequest,
+    transformResponse: defaults.transformResponse
   }, options);
 
   var promise = new Promise(function (resolve, reject) {
@@ -10,7 +12,7 @@ function axios(options) {
 
     function onload() {
       if (request.status >= 200 && request.status < 300) {
-        resolve(parse(request.responseText));
+        resolve(transformData(request.responseText, options.headers, options.transformResponse));
       } else {
         onerror();
       }
@@ -41,13 +43,15 @@ function axios(options) {
       );
 
       for (var key in headers) {
-        request.setRequestHeader(key, headers[key]);
+        if (headers.hasOwnProperty(key)) {
+          request.setRequestHeader(key, headers[key]);
+        }
       }
     } catch (e) {
       reject(e);
     }
 
-    request.send(options.data ? JSON.stringify(options.data) : null);
+    request.send(transformData(options.data, options.headers, options.transformRequest));
   });
 
   promise.success = function (fn) {
@@ -69,6 +73,14 @@ function axios(options) {
 
 var CONTENT_TYPE_APPLICATION_JSON = {'Content-Type': 'application/json;charset=utf-8'};
 var defaults = axios.defaults = {
+  transformRequest: [function (data) {
+    return data ? JSON.stringify(data) : null;
+  }],
+
+  transformResponse: [function (data) {
+    return parse(data);
+  }],
+
   headers: {
     common: {'Accept': 'application/json, text/plain, */*'},
     patch: merge(CONTENT_TYPE_APPLICATION_JSON),
@@ -77,6 +89,18 @@ var defaults = axios.defaults = {
   }
 };
 
+function transformData(data, headers, fns) {
+  if (typeof fns === 'function') {
+    return fns(data, headers);
+  }
+
+  forEach(fns, function (fn) {
+    data = fn(data, headers);
+  });
+
+  return data;
+}
+
 function parse(response) {
   try {
     return JSON.parse(response);