绝对 URL 省略了协议(方案) ，以保留当前页面之一

我看到了 //somepage.com/resource的网址格式，例如:

<img src="//remotesite.com/image1.jpg" />

关键在于，如果当前页面(定义 img标记的页面)正在使用 http，那么对远程站点的请求将通过 http 发出。如果是 https-就是 https。这将消除未完全加密的页面的浏览器警告。

我的问题是——这种 URL 格式对所有浏览器都安全吗? 它是一种标准吗？

35436 次浏览
小开

Yes I believe it is. Paul Irish coined the term Protocol Relative URL.

I'd also point out it's part of the HTML5Boilerplate project which evangelises cross browser compatibility.

Note: there is an edge case in IE6 with google analytics which is mentioned in Paul's article. So it's not perfect.

小开
最佳答案

is this URL format safe to use for all browsers.

I can't say anything for sure, but you should be able to test it in different browsers.

And is it a standard?

Technically, it is called "network-path reference" according to RFC 3986. Here is the scheme for it:

  relative-ref  = relative-part [ "?" query ] [ "#" fragment ]


relative-part = "//" authority path-abempty
/ path-absolute
/ path-noscheme
/ path-empty

There is a problem though, when used on a <link> or @import, IE7 and IE8 download the file.

Here is a post written by Paul Irish on the subject:

小开

Should be safe.

Is specified as format to use in Google's HTML/CSS styleguide: EDIT: latest url : https://google.github.io/styleguide/htmlcssguide.xml#Protocol


提交答案