http - 在 HTTP header 中表示真值和假值的标准格式是什么？

Question

我需要向 HTTP 请求添加自定义 header ，其值的类型将为 bool 值。但是，HTTP header 值都是字符串。那么在这种情况下表示 bool 值的常见做法是什么？ 0/1 , false/true , False/True , off/on ， 等等？

例如。

My-Header: 1

或者一般推荐什么，即最常用的约定？

Answer 1

更新:使用 header exists 可能最有意义对比 doesn't exist约定为 implied here
HTTP 头操作 http header .EXISTS

Returns a Boolean TRUE if an instance of the specified header type exists. Following is an example:

http.req.header("CacheControl").exists

我想答案是?0对比 ?1 Structured Field Values for HTTP > 3.3.6. Booleans

Boolean values can be conveyed in Structured Fields.

The ABNF for a Boolean is:

sf-boolean = "?" boolean

boolean = "0" / "1"

bool 值用前导“？”表示字符后跟“1”
为真值或“0”为假。例如:

Example-Boolean: ?1

退房 Sec-Fetch-User :

Syntax

Sec-Fetch-User: ?0

Sec-Fetch-User: ?1

Values

The value is a Boolean Structured Header.

?0 The navigation request was triggered by a user activation.

?1 The navigation request was triggered by something other than a user activation.

但后来， Save-Data 似乎也是接受值的标准/官方“ bool 值” header "on"对比 "off" Save-Data

A boolean that indicates the user agent's preference for reduced data usage.

( https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers )

A numerical value indicating whether the client wants to opt in to reduced data usage mode. on indicates yes, while off (the default) indicates no.

同样令人困惑的是，ABNF page实际上说:

boolean = ( "true" / "1" ) /

( "false" / "0" )