node.js express 4.0 中的“扩展”是什么意思？

What does 'extended' mean in express 4.0?

提问by KimCrab

I'm using express and also body-parser in my app.

我在我的应用程序中使用 express 和 body-parser。

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

But, What does 'extended' mean in express 4.0?

但是，“扩展”在 express 4.0 中是什么意思？

I found this

我找到了这个

extended - parse extended syntax with the qs module.

However, I still can't understrand what it means.

但是，我仍然无法理解这意味着什么。

回答by Wayne Chiu

If extendedis false, you can not post "nested object"

如果extended是false，则不能发布“嵌套对象”

person[name] = 'cw'

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

If extendedis true, you can do whatever way that you like.

如果extended是true，你可以做任何你喜欢的方式。

回答by Andrew Lam

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

当extended属性设置为 时true，将使用qs 库解析 URL 编码的数据。

On the contrary,

相反，

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

当extended属性设置为 时false，URL 编码的数据将改为使用查询字符串库进行解析。

---

---

The differences between parsing with `qs library` vs `querystring library`

用`qs library` 和`querystring library` 解析的区别

• qslibrary allows you to create a nestedobject from your query string.

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

  
  

• query-stringlibrary does notsupport creating a nested object from your query string.

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

  
  

• qslibrary will notfilter out '?' from the query string.

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

  
  

• query-stringlibrary will filter out '?' from the query string.

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

• qs库允许您从查询字符串创建嵌套对象。

  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您的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库不会过滤掉'?' 从查询字符串。

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

  
  

• 查询字符串库将过滤掉 '?' 从查询字符串。

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

---

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

For more information, you may refer to Leonid Beschastny's answer, and npm compare qs vs query-string.

有关更多信息，您可以参考Leonid Beschastny 的回答和npm compare qs vs query-string。

回答by Logan Tegman

From the Body-Parser docs:

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).

包含解析数据的新主体对象填充在中间件之后的请求对象上（即 req.body）。该对象将包含键值对，其中值可以是字符串或数组（当扩展为假时）或任何类型（当扩展为真时）。

And

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.

扩展选项允许在使用查询字符串库（当为假）或 qs 库（当为真）解析 URL 编码数据之间进行选择。“扩展”语法允许将丰富的对象和数组编码为 URL 编码格式，从而实现类似 JSON 的 URL 编码体验。有关更多信息，请参阅 qs 库。

Basically extended allows you to parse full objects.

基本上扩展允许您解析完整的对象。

Body Parser: Url Encoded

正文解析器：网址编码