确定请求是通过浏览器 bookmark/favorite 还是 link？
Determine if a request was via a browser bookmark/favorite vs a link?
假设我在一个网站上查看 https://whateverxyz.com/index 的主页。那我要么
- (A)点击页面HTML中的一个导航link到
https://whateverxyz.com/app1.html
- (B) 点击浏览器书签即可
https://whateverxyz.com/app1.html
服务器能否区分请求是来自 A 还是 B？ app1.html 上的客户端 JavaScript 运行 可以区分吗？
恐怕，你是查不出来的！
它只能在浏览器扩展中访问。
Citate from your question:
- Can the server tell the difference between whether request was from A or B?
- Can client-side JavaScript running on app1.html tell the difference?
在这两种情况下都无法检测到差异。
官方资源怎么说？
Citate from RFC 7231 - Hypertext Transfer Protocol (HTTP/1.1)
If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard, or an entry within the
user's bookmarks/favorites), the user agent MUST either exclude the
Referer field or send it with a value of "about:blank".
The Referer field has the potential to reveal information about the request context or browsing history of the user, which is a privacy
concern if the referring resource's identifier reveals personal
information (such as an account name) or a resource that is supposed
to be confidential (such as behind a firewall or internal to a secured
service). Most general-purpose user agents do not send the Referer
header field when the referring resource is a local "file" or "data"
URI. A user agent MUST NOT send a Referer header field in an
unsecured HTTP request if the referring page was received with a
secure protocol. See Section
9.4 for additional security considerations.
了解更多信息：
备选方案
但是你可以在客户端做一些事情。在页面 https://whateverxyz.com/index 中，您可以在 JavaScript 中编写一个侦听器，用于检测此页面 link 上的所有点击。在点击事件中，您可以在 cookie 中写入 link URL 和 time，一个IndexedDB 或 localStorage。然后在页面 https://whateverxyz.com/app1.html 你必须阅读这些信息。如果此信息不是未定义的，则它来自 link，而在所有其他情况下，它来自书签（或者可能是在地址栏或其他任何地方提示）。
查看相关问题：
- How to client-side detect when a page is bookmarked?
- How to detect if a link already is in the user's bookmarks?
- Is there a way to know if someone has bookmarked your website?
您可以在页面加载后设置查询参数JavaScript。 （使用 history.pushState 所以它不会重新加载）。喜欢：
history.pushState({}, "", "?bookmarked")
因此，当导航来自书签时，它带有 ?bookmarked 参数，而当它是常规导航时，您将在没有任何参数的情况下获得它。
Working example, Code for example
编辑：正如评论中所指出的，这种方法有两个问题。
- 浏览器中的 URL 栏将始终包含
?bookmarked 查询参数。
- 重新加载时，服务器将获得
?bookmarked，即使它不是来自书签。 （可以按照 this question 的答案中指出的方法解决）
假设我在一个网站上查看 https://whateverxyz.com/index 的主页。那我要么
- (A)点击页面HTML中的一个导航link到
https://whateverxyz.com/app1.html - (B) 点击浏览器书签即可
https://whateverxyz.com/app1.html
服务器能否区分请求是来自 A 还是 B？ app1.html 上的客户端 JavaScript 运行 可以区分吗？
恐怕，你是查不出来的！ 它只能在浏览器扩展中访问。
Citate from your question:
- Can the server tell the difference between whether request was from A or B?
- Can client-side JavaScript running on app1.html tell the difference?
在这两种情况下都无法检测到差异。
官方资源怎么说？
Citate from RFC 7231 - Hypertext Transfer Protocol (HTTP/1.1)
If the target URI was obtained from a source that does not have its own URI (e.g., input from the user keyboard, or an entry within the user's bookmarks/favorites), the user agent MUST either exclude the Referer field or send it with a value of "about:blank".
The Referer field has the potential to reveal information about the request context or browsing history of the user, which is a privacy concern if the referring resource's identifier reveals personal information (such as an account name) or a resource that is supposed to be confidential (such as behind a firewall or internal to a secured service). Most general-purpose user agents do not send the Referer header field when the referring resource is a local "file" or "data" URI. A user agent MUST NOT send a Referer header field in an unsecured HTTP request if the referring page was received with a secure protocol. See Section 9.4 for additional security considerations.
了解更多信息：
备选方案
但是你可以在客户端做一些事情。在页面 https://whateverxyz.com/index 中，您可以在 JavaScript 中编写一个侦听器，用于检测此页面 link 上的所有点击。在点击事件中，您可以在 cookie 中写入 link URL 和 time，一个IndexedDB 或 localStorage。然后在页面 https://whateverxyz.com/app1.html 你必须阅读这些信息。如果此信息不是未定义的，则它来自 link，而在所有其他情况下，它来自书签（或者可能是在地址栏或其他任何地方提示）。
查看相关问题：
- How to client-side detect when a page is bookmarked?
- How to detect if a link already is in the user's bookmarks?
- Is there a way to know if someone has bookmarked your website?
您可以在页面加载后设置查询参数JavaScript。 （使用 history.pushState 所以它不会重新加载）。喜欢：
history.pushState({}, "", "?bookmarked")
因此，当导航来自书签时，它带有 ?bookmarked 参数，而当它是常规导航时，您将在没有任何参数的情况下获得它。
Working example, Code for example
编辑：正如评论中所指出的，这种方法有两个问题。
- 浏览器中的 URL 栏将始终包含
?bookmarked查询参数。 - 重新加载时，服务器将获得
?bookmarked，即使它不是来自书签。 （可以按照 this question 的答案中指出的方法解决）