修复无效 JSON 的正则表达式

我正在对服务进行 API 调用，但它返回无效的 JSON。 photo_url 字段没有将 url 封装在引号中。我将它作为字符串，并尝试编写一个正则表达式来在 url 周围添加引号。我使用 Titanium 在 Javascript 中完成这一切。

这是我现在的代码：

var response = '[{"friend_request":{"about_me":"","friend_id":"11043271728","gender":"M","display_name":"foo","age":21,"photo_url":http:\/\/s.foo.com\/img\/nopic\/MB_90x90_male.gif,"hometown":""},"friend_request":{"hometown":"","display_name":"bar","gender":"M","age":"","friend_id":"11040542298","about_me":"","photo_url":http:\/\/s.foo.com\/img\/nopic\/MB_90x90_male.gif}}]';
var pattern = /http.*(,|\}|\s)/i;
var flip = target.match(pattern);
var foo  = target.replace(flip, "\"" + flip + "\"");
console.log(foo);

这是人类可读形式的 JSON：

[
  {
    "friend_request": {
      "about_me": "",
      "friend_id": "11043271728",
      "gender": "M",
      "display_name": "foo",
      "age": 21,
      "photo_url": http:\/\/s.foo.com\/img\/nopic\/MB_90x90_male.gif,
      "hometown": ""
    },
    "friend_request": {
      "hometown": "",
      "display_name": "bar",
      "gender": "M",
      "age": "",
      "friend_id": "11040542298",
      "about_me": "",
      "photo_url": http:\/\/s.foo.com\/img\/nopic\/MB_90x90_male.gif
    }
  }
]

目前，它正在寻找该模式的起点，但仍在进一步发展。我相信这与逗号有关。我知道应该发生多个模式匹配，但现在，我只是想让一个模式匹配工作。在此先感谢您的帮助。

var response = '[{"friend_request":{"about_me":"","friend_id":"11043271728","gender":"M","display_name":"foo","age":21,"photo_url":http:\/\/s.foo.com\/img\/nopic\/MB_90x90_male.gif,"hometown":""},"friend_request":{"hometown":"","display_name":"bar","gender":"M","age":"","friend_id":"11040542298","about_me":"","photo_url":http:\/\/s.foo.com\/img\/nopic\/MB_90x90_male.gif}}]';

var str = response.replace( /("photo_url":)([^,}]+)([,\}])/g, '$1"$2"$3' )