Implement use_location

[rmorshea]

By providing access to a use_location hook, users can implement primitive routing. The catch is that, at present, state will not be persisted as users navigate between routes. Support for that will have to come in a future update.

[Archmonger]

Can you shoot me a sample snippet of the syntax for this so I can test?

[rmorshea]

@Archmonger here's a demo of how it should work:

fromidomimporthtml, component, runfromidom.serverimportstarletteasserver@componentdefShowLocation():
loc=server.use_location()
returnhtml.h1(loc.pathname+loc.search)
run(ShowLocation, implementation=server)

[Archmonger]

Might want to rename the PR to "use_location hook" since this isn't routing, but rather location propagation.

Routing = integrated support for rendering different components based on regex path

[rmorshea]

@Archmonger, any idea why this test is failing on Windows?

[Archmonger]

The way that test is written, I wouldn't expect it to raise anything on any OS?

From what I can tell,

1. Create /dir/file.txt
2. Create /escaped-file.txt via symlink
3. Check if /dir/file.txt is safe

Why would you expect /dir/file.txt to be unsafe?

[Archmonger]

Scratch that, I see you're trying to symlink the empty /dir/file.txt to a /escaped-file.txt.

I don't think this is a valid test case to be honest. If the user intentionally symlinked a file into our dir, we should consider it safe. In general, symlinks/hardlinks should be considered as "real files" within both their given directories.

If you want this to fail for some reason, you'd need to use os.path.realpath() or Path.absolute() to follow the symlink to it's origin.