ngCookies都做了什么

  根据官方的api文档，ngCookies的$cookieStore服务，提供了这样几个方法：

   1.get(key);


   2.put(key, value);

   3.remove(key);

  以上方法都是对cookie进行写入、读取、删除操作，那么我们来看下源码（截取了部分源码），它都做了什么。

  getAll: function() {
     return $$cookieReader();
   },

  put: function(key, value, options) {
     $$cookieWriter(key, value, calcOptions(options));
  },

  remove: function(key, options) {
     $$cookieWriter(key, undefined, calcOptions(options));
  }

  概览以上代码可知，无非就是调用了$$cookieReader()和$$cookieWriter()两个方法，写入与删除用第二个参数区分。接下来我们来看一下$$cookieWriter()。

function $$CookieWriter($document, $log, $browser) {
  var cookiePath = $browser.baseHref();
  var rawDocument = $document[0];

  function buildCookieString(name, value, options) {
    var path, expires;
    options = options || {};
    expires = options.expires;
    path = angular.isDefined(options.path) ? options.path : cookiePath;
    if (angular.isUndefined(value)) {
      expires = 'Thu, 01 Jan 1970 00:00:00 GMT';
      value = '';
    }
    if (angular.isString(expires)) {
      expires = new Date(expires);
    }

    var str = encodeURIComponent(name) + '=' + encodeURIComponent(value);
    str += path ? ';path=' + path : '';
    str += options.domain ? ';domain=' + options.domain : '';
    str += expires ? ';expires=' + expires.toUTCString() : '';
    str += options.secure ? ';secure' : '';

    // per http://www.ietf.org/rfc/rfc2109.txt browser must allow at minimum:
    // - 300 cookies
    // - 20 cookies per unique domain
    // - 4096 bytes per cookie
    var cookieLength = str.length + 1;
    if (cookieLength > 4096) {
      $log.warn("Cookie '" + name +
        "' possibly not set or overflowed because it was too large (" +
        cookieLength + " > 4096 bytes)!");
    }

    return str;
  }

  return function(name, value, options) {
    rawDocument.cookie = buildCookieString(name, value, options);
  };
}

  首先，它通过encodeURIComponent()将key和value进行编码，接下来拼字符串时加“=”，这些是为了$$cookieReader()做准备。然后追加一些其他信息，然后限制长度,最后通过$document[0].cookie存到cookie中。不同在于，$$cookieWriter()在angular-cookie中，而$$cookieReader()却在angular.js中。接下来，我们看一下$$cookieReader()方法做了什么。

function $$CookieReader($document) {
  var rawDocument = $document[0] || {};
  var lastCookies = {};
  var lastCookieString = '';

  function safeDecodeURIComponent(str) {
    try {
      return decodeURIComponent(str);
    } catch (e) {
      return str;
    }
  }

  return function() {
    var cookieArray, cookie, i, index, name;
    var currentCookieString = rawDocument.cookie || '';

    if (currentCookieString !== lastCookieString) {
      lastCookieString = currentCookieString;
      cookieArray = lastCookieString.split('; ');
      lastCookies = {};

      for (i = 0; i < cookieArray.length; i++) {
        cookie = cookieArray[i];
        index = cookie.indexOf('=');
        if (index > 0) { //ignore nameless cookies
          name = safeDecodeURIComponent(cookie.substring(0, index));
          // the first value that is seen for a cookie is the most
          // specific one.  values for the same cookie name that
          // follow are for less specific paths.
          if (isUndefined(lastCookies[name])) {
            lastCookies[name] = safeDecodeURIComponent(cookie.substring(index + 1));
          }
        }
      }
    }
    return lastCookies;
  };
}

   首先，它将cookie取出来，分成数组，然后通过“=”来区分key和value。解析之后将当前和输入的key相等的值取出。

   关于编码的问题，请浏览一下文章：encodeURI和 encodeURIComponent 的作用及应用

   关于js原生的cookie，请见：关于document.cookie的使用

   本文大概解释一下ngCookie的作了什么，怎么做的，如果有不对的地方（很正常 ^__^ ），请指正。