The language switcher needs the same information as languageLinks
needed, namely the list of locales and the current Path, to construct
the URI to all alternate versions. However, in this case i need access
to this data in the template context, to build the list of links.
At first i use request’s context to hold the list of available locales
from application, and it worked, possibly without ill-effects, but i
realized that i was doing it just to avoid a new parameter. Or, more
precise, an _explicit_ parameter; the context was used to skip the
inner functions between app and template.MustRenderPublic, but the
parameter was there all the same.
Finally, i thought that some handler might want to filter the list of
locales to show only the ones that it has a translation of. In that
case, i would need to extract the locales from the context, filter it,
and create a new request with the updated context. That made little
sense, and made me add the explicit locales parameter.
Since now the template has the same data as languageLinks, there is
little point of having the link in the HTTP response headers, and added
the <link> elements to <head>.
I thought that maybe i could avoid these <links> as they give the exact
same data as the language switch, but Google says nothing of using
regular anchors to gather information about localized versions of the
document[0], thus i opted to be conservative. One can reason that the
<head> has more weight for Google, as most sites with user-generated
content, which could contain these anchors, rarely allow users to edit
the <head>.
[0]: https://developers.google.com/search/docs/specialty/international/localized-versions
I really doubt that they are going to use more than a single company,
but the application is based on Numerus, that **does** have multiple
company, and followed the same architecture and philosophy: use the URL
to choose the company to manage, even if the user has a single company.
The reason i use the slug instead of the ID is because i do not want to
make the ID public in case the application is really used by employees
of many unrelated companies: they need not need to guess how many
companies there are based on the ID.
I validate this slug to be a valid UUID instead of relaying on the
query’s empty result because casting a string with a malformed value to
UUID results in an error other than data not found. Not with that
select, but it would fail with a function parameter, and i want to add
that UUID check to all functions that do use slugs.
I based uuid.Valid function on Parse() from Google’s uuid package[0]
instead of using regular expression, as it was my first idea, because
that function is an order of magnitude faster in benchmarks:
goos: linux
goarch: amd64
pkg: dev.tandem.ws/tandem/numerus/pkg
cpu: Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz
BenchmarkValidUuid-4 36946050 29.37 ns/op
BenchmarkValidUuid_Re-4 3633169 306.70 ns/op
The regular expression used for the benchmark was:
var re = regexp.MustCompile("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-4[a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12}$")
And the input parameter for both functions was the following valid UUID,
because most of the time the passed UUID will be valid:
"f47ac10b-58cc-0372-8567-0e02b2c3d479"
I did not use the uuid package as is, even though it is in Debian’s
repository, because i only need to check whether the value is valid,
not convert it to a byte array. As far as i know, that package can not
do that.
Adding the Company struct into auth was not my intention, as it makes
little sense name-wise, but i need to have the Company when rendering
templates and the company package has templates to render, thus using
the company package for the Company struct would create a dependency
loop between template and company. I’ve chosen the auth package only
because User is also there; User and Company are very much related in
this application, but not enough to include the company inside the user,
or vice versa, as the User comes from the cookie while the company from
the URL.
Finally, had to move methodNotAllowed to the http package, as an
exported function, because it is used now from other packages, namely
campsite.
[0]: https://github.com/google/uuid
It does nothing, but i need it to discuss with Oriol.
Now there are more than a single package that requires shiftPath, so
i moved it to http and an exported function, ShiftPath.
Part of #25.
It does nothing more than to server a single page that does nothing
interesting.
This time i do not use a router. Instead, i am trying out a technique
i have seen in an article[0] that i have tried in other, smaller,
projects and seems to work surprisingly well: it just “cuts off” the
URI path by path, passing the request from handler to handler until
it finds its way to a handler that actually serves the request.
That helps to loosen the coupling between the application and lower
handlers, and makes dependencies explicit, because i need to pass the
locale, company, etc. down instead of storing them in contexts. Let’s
see if i do not regret it on a later date.
I also made a lot more packages that in Numerus. In Numerus i actually
only have the single pkg package, and it works, kind of, but i notice
how i name my methods to avoid clashing instead of using packages for
that. That is, instead of pkg.NewApp i now have app.New.
Initially i thought that Locale should be inside app, but then there was
a circular dependency between app and template. That is why i created a
separate package, but now i am wondering if template should be inside
app too, but then i would have app.MustRenderTemplate instead of
template.MustRender.
The CSS is the most bare-bones file i could write because i am focusing
in markup right now; Oriol will fill in the file once the application is
working.
[0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
jordi fita mas