Today I learned a little quirk with closing the current tab/window with Javascript.
So apparently, you cannot use window.close(); to close the current window, unless that window was programmatically opened. But you can close children windows if you kept a reference to them. As it turns out, the children can also close the parent window. And for some reason, if you call window.close('', '_parent', ''), this actually works… but it shouldn’t.
close doesn’t actually take any arguments… (also see mdn)
Reading the html spec, close doesn’t have args either.
Searching the internet, the only thing I could find was this post by natclark.
Apparently _parent, much like the widely known _blank has to do with a tag targets. There’s actually more targets i.e.: _self, and _top.
Here’s an interesting graphic explaining the targets from stackoverflow.
My best guess, is that this works purely for backwards compatibility. There’s even a post talking about a similar workaround/exploit where you can call: window.open(location, '_self').close() that seems like it worked the same way.
I believe, that close takes arguments for backwards compatibility purposes, but the arguments are deprecated, so they’re not documented anymore. So if browsers lost this ability, you couldn’t blame them since its not in the docs.
window.close('', '_parent', '') seems to work because close tries to get the parent of the current window, finds that it is the top parent, so it then closes it’s parent aka itself. Honestly, kind of strange still, the other workaround makes more sense.
window.open(location, '_self').close(): on the other hand, tries to open a window, but since _self already exists, then it gets reused and then we can call close on it, but since it was “opened” via Javascript, it no longer is blocked.
