javascript - know if a link has already been opened

Question

I'd like to know if there is a way to know if a link has already been opened. In firefox, the color of a link changes once you clicked it, so I guess it's possible.

Edit : This is for a firefox extension, so I can't change the HTML or CSS file.

Thanks :)

Answer 1

Indeed, it is possible.

One way is to have different css classes:

a:visited { color : red; }
a { color : orange; }

Then detect that (in JavaScript).

Answer 2

If you don't want the links to have different colours, you can also apply some CSS that will turn out invisible

a:visited { padding-left: 1px; margin-left: -1px; }
a { padding-left: 2px; margin-left: -2px; }

Answer 3

您可以为未访问的（ :link ）和访问过的链接（ :visited ）指定不同的颜色，并检查链接的当前颜色是否具有访问者的颜色。

Answer 4

Unfortunately it is possible to see what links were visited. I am saying unfortunately as it is considered a privacy violation. A while ago I came across this blog post Spyjax – Your browser history is not private! which describes this.