'extended' 在 express 4.0 中是什么意思？

Question

我在我的应用中使用了 express 和 body-parser。

app.use(bodyParser.urlencoded({ extended: false }));

但是，'extended' 在 express 4.0 中是什么意思？

我找到了这个

extended - parse extended syntax with the qs module.

不过，我还是没明白是什么意思

Answer 1

来自 Body-Parser 文档：

A new body object containing the parsed data is populated on the request object after the middleware (i.e. req.body). This object will contain key-value pairs, where the value can be a string or array (when extended is false), or any type (when extended is true).

和

The extended option allows to choose between parsing the URL-encoded data with the querystring library (when false) or the qs library (when true). The "extended" syntax allows for rich objects and arrays to be encoded into the URL-encoded format, allowing for a JSON-like experience with URL-encoded. For more information, please see the qs library.

基本扩展允许您解析完整对象。

Body Parser: Url Encoded

Answer 2

如果extended是false，则不能post"nested object"

person[name] = 'cw'

// Nested Object = { person: { name: cw } }

如果extended是true，你可以随心所欲。

Answer 3

When extended property is set to true, the URL-encoded data will be parsed with the qs library.

相反，

when extended property is set to false, the URL-encoded data will instead be parsed with the querystring library.

---

使用 `qs 库` 与 `querystring 库` 进行解析的区别

• qs 库允许您从查询字符串创建 nested 对象。

  var qs = require("qs")
  var result = qs.parse("person[name]=bobby&person[age]=3")
  console.log(result) // { person: { name: 'bobby', age: '3' } }
  

  
  

• 查询字符串库不支持从查询字符串创建嵌套对象。

  var queryString = require("query-string")
  var result = queryString.parse("person[name]=bobby&person[age]=3")
  console.log(result) // { 'person[age]': '3', 'person[name]': 'bobby' }
  

  
  

• qs 库将 not 过滤掉 '?'来自查询字符串。

  var qs = require("qs")
  var result = qs.parse("?a=b")
  console.log(result) // { '?a': 'b' }
  

  
  

• query-string 库会过滤掉'?'来自查询字符串。

  var queryString = require("query-string")
  var result = queryString.parse("?a=b")
  console.log(result) // { a: 'b' }
  

---

app.use(bodyParser.urlencoded({ extended: true })) // for parsing application/x-www-form-urlencoded

更多信息，您可以参考, and npm compare qs vs query-string.