node.js - 做一个单页网站，用ajax时，相应的后端用node要怎么写

Question

菜鸟遇到的问题是：pjax改变url，并作相应刷新局部页面。但是如果直接进入到这个url，就会出现问题（页面显示Ajax返回的JSON数据），求大神提供个正确思路

Answer 1

My method is to use the Accept header to determine the request type.
For example, for the same url, /products:
When requesting, set accept to text/html and the method to get, then an html page will be returned.
If accept is application/json and the method is get, a product list in json format is returned. /products?limit=20 will return the first 20 items in the list.
If accept is application/json and the method is put, a product will be added.
That's probably it, control the result of the request through url, http method, accept,

Request URL:/products
Request Method:GET

Request Headers
Accept:application/json, text/plain, */*

Response Headers
date:Sun, 24 Nov 2013 07:02:46 GMT
items-count:3
page-count:1
page-number:1
page-step:20
Server:BWS/1.0
vary:Accept-Encoding
x-powered-by:Express

Answer 2

It would be easier if the backend used the express framework.

res.format({
  'text/html': function() {
    // 这里是直接用 url 访问的 render 逻辑
    // res.render('products', {...});
  },
  'application/json': function() {
    // 这里是 ajax 方式的逻辑
    // res.send({...});
  }
});

Answer 3

Most JavaScript frameworks will include a request header identifying Ajax when sending an Ajax request:

{"HTTP_X_REQUESTED_WITH" : "XmlHttpRequest"}

If not, you can set one manually, in jQuery it is like this:

$.ajax {
  beforeSend: function(jqXHR, settings) {
    jqXHR.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
  }
};

In this way, the server can make a judgment based on the request header, similar to this:

if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
     /* special ajax here */
     // send JSON data
 } else {
     // send html data
 }