TOMMYHU

The jqXHR objects returned by $.ajax() as of jQuery 1.5 implement the Promise interface, giving them all the properties, methods, and behavior of a Promise (see Deferred object for more information). These methods take one or more function arguments that are called when the $.ajax() request terminates. This allows you to assign multiple callbacks on a single request, and even to assign callbacks after the request may have completed. (If the request is already complete, the callback is fired immediately.) Available Promise methods of the jqXHR object include:

jqXHR.done(function( data, textStatus, jqXHR ) {});
An alternative construct to the success callback option, the .done() method replaces the deprecated jqXHR.success() method. Refer to deferred.done() for implementation details.

jqXHR.fail(function( jqXHR, textStatus, errorThrown ) {});
An alternative construct to the error callback option, the .fail() method replaces the deprecated .error() method. Refer to deferred.fail() for implementation details.

jqXHR.always(function( data|jqXHR, textStatus, jqXHR|errorThrown ) { });
An alternative construct to the complete callback option, the .always() method replaces the deprecated .complete() method.

In response to a successful request, the function's arguments are the same as those of .done(): data, textStatus, and the jqXHR object. For failed requests the arguments are the same as those of .fail(): the jqXHR object, textStatus, and errorThrown. Refer to deferred.always() for implementation details.

jqXHR.then(function( data, textStatus, jqXHR ) {}, function( jqXHR, textStatus, errorThrown ) {});
Incorporates the functionality of the .done() and .fail() methods, allowing (as of jQuery 1.8) the underlying Promise to be manipulated. Refer to deferred.then() for implementation details.

Deprecation Notice: The jqXHR.success(), jqXHR.error(), and jqXHR.complete() callbacks are deprecated as of jQuery 1.8. To prepare your code for their eventual removal, use jqXHR.done(), jqXHR.fail(), and jqXHR.always() instead.
// Assign handlers immediately after making the request, // and remember the jqXHR object for this request var jqxhr = $.ajax( "example.php" )   .done(function() {     alert( "success" );   })   .fail(function() {     alert( "error" );   })   .always(function() {     alert( "complete" );   }); // Perform other work here ... // Set another completion function for the request above jqxhr.always(function() {   alert( "second complete" ); });
The this reference within all callbacks is the object in the context option passed to $.ajax in the settings; if context is not specified, this is a reference to the Ajax settings themselves.

For backward compatibility with XMLHttpRequest, a jqXHR object will expose the following properties and methods:

readyState
status
statusText
responseXML and/or responseText when the underlying request responded with xml and/or text, respectively
setRequestHeader(name, value) which departs from the standard by replacing the old value with the new one rather than concatenating the new value to the old one
getAllResponseHeaders()
getResponseHeader()
statusCode()
abort()
No onreadystatechange mechanism is provided, however, since done, fail, always, and statusCode cover all conceivable requirements.

Callback Function Queues

The beforeSend, error, dataFilter, success and complete options all accept callback functions that are invoked at the appropriate times.

As of jQuery 1.5, the fail and done, and, as of jQuery 1.6, always callback hooks are first-in, first-out managed queues, allowing for more than one callback for each hook. See Deferred object methods, which are implemented internally for these $.ajax() callback hooks.

The callback hooks provided by $.ajax() are as follows:

beforeSend callback option is invoked; it receives the jqXHR object and the settings object as parameters.
error callback option is invoked, if the request fails. It receives the jqXHR, a string indicating the error type, and an exception object if applicable. Some built-in errors will provide a string as the exception object: "abort", "timeout", "No Transport".
dataFilter callback option is invoked immediately upon successful receipt of response data. It receives the returned data and the value of dataType, and must return the (possibly altered) data to pass on to success.
success callback option is invoked, if the request succeeds. It receives the returned data, a string containing the success code, and the jqXHR object.
Promise callbacks — .done(), .fail(), .always(), and .then() — are invoked, in the order they are registered.
complete callback option fires, when the request finishes, whether in failure or success. It receives the jqXHR object, as well as a string containing the success or error code.

官方文档写的很详细：http://api.jquery.com/jquery.ajax/
complete: function (XMLHttpRequest, textStatus) {     //textStatus的值：success,notmodified,nocontent,error,timeout,abort,parsererror }, error: function (XMLHttpRequest, textStatus, errorThrown) {     //textStatus的值：null, timeout, error, abort, parsererror     //errorThrown的值：收到http出错文本，如 Not Found 或 Internal Server Error. }
注意：complete和error时的textStatus不一样。


error: function(XMLHttpRequest, textStatus, errorThrown) {     alert(XMLHttpRequest.status);    //http响应状态     alert(XMLHttpRequest.readyState);//5个状态     alert(textStatus);               //六个值 },

使用nginx搭建https服务器，最近在研究nginx，整好遇到一个需求就是希望服务器与客户端之间传输内容是加密的，防止中间监听泄露信息，但是去证书服务商那边申请证书又不合算，因为访问服务器的都是内部人士，所以自己给自己颁发证书，忽略掉浏览器的不信任警报即可。下面是颁发证书和配置过程。

首先确保机器上安装了openssl和openssl-devel
#yum install openssl #yum install openssl-devel 然后就是自己颁发证书给自己 #cd /usr/local/nginx/conf #openssl genrsa -des3 -out server.key 1024 #openssl req -new -key server.key -out server.csr #openssl rsa -in server.key -out server_nopwd.key #openssl x509 -req -days 365 -in server.csr -signkey server_nopwd.key -out server.crt
至此证书已经生成完毕，下面就是配置nginx
server {     listen 443;     ssl on;     ssl_certificate  /usr/local/nginx/conf/server.crt;     ssl_certificate_key  /usr/local/nginx/conf/server_nopwd.key; }
然后重启nginx即可。

ps： 如果出现“[emerg] 10464#0: unknown directive "ssl" in /usr/local/nginx-0.6.32/conf/nginx.conf:74”则说明没有将ssl模块编译进nginx，在configure的时候加上“--with-http_ssl_module”即可^^

至此已经完成了https服务器搭建，但如何让浏览器信任自己颁发的证书呢？

今天终于研究捣鼓出来了，只要将之前生成的server.crt文件导入到系统的证书管理器就行了，具体方法：

控制面板 -> Internet选项 -> 内容 -> 发行者 -> 受信任的根证书颁发机构 -> 导入 -》选择server.crt

HTTP请求方法并不是只有GET和POST，只是最常用的。据RFC2616标准（现行的HTTP/1.1）得知，通常有以下8种方法：OPTIONS、GET、HEAD、POST、PUT、DELETE、TRACE和CONNECT。

使用node作为apiserver提供数据，h5ajax请求是无论如何过不了，

试探请求


真实请求

最终为node只支持了post和get，而没有对request method为options的请求做处理
添加如下代码搞定问题
    if (request.method == 'OPTIONS') {         response.setHeader("Access-Control-Allow-Origin", "*");         response.setHeader('Access-Control-Allow-Methods', 'GET, POST, DELETE, HEAD, OPTIONS');         response.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization, Accept, X-Requested-With');         response.setHeader('Content-Length', 0);         app.res.httpError(response,app.err.http.success);         return;     }

Flex 布局教程
http://www.ruanyifeng.com/blog/2015/07/flex-grammar.html

ECMAScript 6入门电子书
http://es6.ruanyifeng.com/#docs/intro

Node.js 4.x的长期支持会在2017年4月截止，因而大家还有充足的时间切换到6.0x版本。2016年10月之前，Version 0.10和0.12只会收到维护更新；之后会在2016年12月迎来EoL（生命周期终止）。

node-js-version-6-released-with-long-term-support-503452-3.png
值得一提的是，Node.js 6覆盖了93%的ECMAScript 6（发布于去年6月的JavaScript 2015标准）特性。相比之下，Node.js 5x仅支持56%的ES6标准。
团队还隆重介绍了全新的模块加载系统，据说速度是Node.js 4.x的四倍以上。其它显著变动还有Node.js 6已经切换到使用Google V8 5.0版本（作为Node的JavaScript引擎），以及大量bug修复和性能改进。
[编译自：Soft Pedia]

例如要杀掉hello这个进程，使用下面这个命令就能直接实现。

ps -ef |grep hello |awk '{print $2}'|xargs kill -9
这里是输出ps -ef |grep hello 结果的第二列的内容然后通过xargs传递给kill -9,其实第二列内容就是hello的进程号！
附录：
1,awk是一种编程语言，用于在linux/unix下对文本和数据进行处理。数据可以来自标准输入、一个或多个文件，或其它命令的输出。它支持用户自定义函数和动态正则表达式等先进功能，是linux/unix下的一个强大编程工具。它在命令行中使用，但更多是作为脚本来使用。awk的处理文本和数据的方式是这样的，它逐行扫描文件，从第一行到最后一行，寻找匹配的特定模式的行，并在这些行上进行你想要的操作。如果没有指定处理动作，则把匹配的行显示到标准输出(屏幕)，如果没有指定模式，则所有被操作所指定的行都被处理。awk分别代表其作者姓氏的第一个字母。因为它的作者是三个人，分别是Alfred Aho、Brian Kernighan、Peter Weinberger。gawk是awk的GNU版本，它提供了Bell实验室和GNU的一些扩展。
2. xargs是给命令传递参数的一个过滤器，也是组合多个命令的一个工具。它把一个数据流分割为一些足够小的块，以方便过滤器和命令进行处理。通常情况下，xargs从管道或者stdin中读取数据，但是它也能够从文件的输出中读取数据。xargs的默认命令是echo，这意味着通过管道传递给xargs的输入将会包含换行和空白，不过通过xargs的处理，换行和空白将被空格取代。xargs 是一个强有力的命令，它能够捕获一个命令的输出，然后传递给另外一个命令.

https://github.com/AutumnsWind/Front-end-tutorial
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