Add HTTPServerRequest.routerRootDir property

[Yoplitein]

This allows for emitting the correct path when using a URLRouter with a prefix.

Consider the index of a router with prefix "/a/deep/path" which renders:

a(href="#{req.rootDir}") rootDir
a(href="#{req.routerRootDir}") routerRootDir

The following is output:

<a href="../../../">rootDir</a>
<a href="../../../a/deep/path/">routerRootDir</a>

[s-ludwig]

This idea sounds useful, I worked around this by hand for some projects already. For new projects , something similar for registerWebInterface would be similarly useful.

I see a two issues with the concrete approach:

• This obviously only works for a single router, but routers could be nested. Probably not the common case, but it exists. A solution would be to update the request when an actual route match was found instead of once at the beginning.
• The router is a higher level concept that is layered on top. The low-level HTTP API shouldn't be affected by it. What I'd propose is to simply put the relative path into HTTPServerRequest.params["routerRootDir"] instead. For computing the relative path, it's probably a good idea to use Path.relativeTo, to get a shorter path.

[Yoplitein]

I'm trying to use Path, but I can't figure out how to wrangle it into submission.
The following was the only way I could get it to actually do anything:

Path path = Path([PathEntry("a"), PathEntry("deep"), PathEntry("path")], true);
Path root = Path([PathEntry(".."), PathEntry(".."), PathEntry("..")], true);
string routerRootDir = path.relativeTo(root).toString;

Everything else causes the assert at path.d:145 to fail.
And it still emits ../../../a/deep/path.

How do I properly go about this?

[s-ludwig]

It should be Path(router.prefix).relativeTo(Path(req.path)).toString() - assuming that both, router.prefix and req.path, start with a "/", which should always be true.

[Yoplitein]

That doesn't seem to be quite right either.

For paths without a trailing slash, it leaves off the topmost path component. E.g. /a/deep/path/param => /a/deep/
And at the index of the router, it is equivalent to req.rootDir.

Edit: I should mention this is how the browser handles it.

[s-ludwig]

Hm right, forgot about that, this issue just came up somewhere else recently. Trailing slash handling doesn't quite match the rules needed here. This should fix it:

auto rp = Path(req.path);
if (!rp.endsWithSlash) rp = rp[0 .. $-1];
string result = Path(prefix).relativeTo(req.path).toString();

[Yoplitein]

Ok, I think that's all the edge cases ironed out. Thanks for the help.

[s-ludwig]

Thanks, looks good.