This page is more or less similar to home, in terms of database: it
has a carousel and a list of items; in this case, the definition of
campsite services.
As i said early, when adding the home carousel, this carousel has its
own relation and set of functions to manage slides. They are also
duplicated in Go code, but i think i will need to refactor it later to
a carousel package or something like that, because both relations have
the exact same fields and types, so it makes no sense to have twice the
same code.
I already did it with the CSS and JavaScript code, mostly because it was
easier to replace the `.surroundings div` selector with `.carousel`, and
because that way i can have a single template that loads and initializes
Slick.
There is no UI to create or edit service definitions, although there are
the SQL functions, because i have no more time now, and Oriol needs to
check that the style is correct for that page.
I debated with myself whether to create the home_carousel relation or
rather if it would be better to have a single carousel relation for all
pages. However, i thought that it would be actually harder to maintain
a single relation because i would need an additional column to tell one
carrousel from another, and what would that column be? An enum? A
foreign key to another relation? home_carousel carries no such issues.
I was starting to duplicate logic all over the packages, such as the
way to encode media paths or “localization” (l10n) input fields.
Therefore, i refactorized them.
In the case of media path, i added a function that accepts rows of
media, because always need the same columns from the row, and it was
yet another repetition if i needed to pass them all the time. Plus,
these kind of functions can be called as `table.function`, that make
them look like columns from the table; if PostgreSQL implemented virtual
generated columns, i would have used that instead.
I am not sure whether that media_path function can be immutable. An
immutable function is “guaranteed to return the same results given the
same arguments forever”, which would be true if the inputs where the
hash and the original_filename columns, instead of the whole rows, but
i left it as static because i did not know whether PostgreSQL interprets
the “same row but with different values” as a different input. That is,
whether PostgreSQL’s concept of row is the actual tuple or the space
that has a rowid, irrespective of contents; in the latter case, the
function can not be immutable. Just to be in the safe side, i left it
stable.
The home page was starting to grow a bit too much inside the app
package, new that it has its own admin handler, and moved it all to a
separate package.
This is the image that is shown at the home page, and maybe other pages
in the future. We can not use a static file because this image can be
changed by the customer, not us; just like name and description.
I decided to keep the actual media content in the database, but to copy
this file out to the file system the first time it is accessed. This is
because we are going to replicate the database to a public instance that
must show exactly the same image, but the customer will update the image
from the private instance, behind a firewall. We could also synchronize
the folder where they upload the images, the same way we will replicate,
but i thought that i would make the whole thing a little more brittle:
this way if it can replicate the update of the media, it is impossible
to not have its contents; dumping it to a file is to improve subsequent
requests to the same media.
I use the hex representation of the media’s hash as the URL to the
resource, because PostgreSQL’s base64 is not URL save (i.e., it uses
RFC2045’s charset that includes the forward slash[0]), and i did not
feel necessary write a new function just to slightly reduce the URLs’
length.
Before checking if the file exists, i make sure that the given hash is
an hex string, like i do for UUID, otherwise any other check is going
to fail for sure. I moved out hex.Valid function from UUID to check for
valid hex values, but the actual hash check is inside app/media because
i doubt it will be used outside that module.
[0]: https://datatracker.ietf.org/doc/html/rfc2045#section-6.8
As previously stated, web made the design with an external tool and
had to “convert” it to proper CSS and HTML markup.
Unfortunately, the original design uses slick, that requires jQuery;
i can’t do anything about it now.
Disabled most of the menu and language switcher because it is not in the
design yet.
I need to check that the user is an employee (or admin) in
administration handlers, but i do not want to do it for each handler,
because i am bound to forget it. Thus, i added the /admin sub-path for
these resources.
The public-facing web is the rest of the resources outside /admin, but
for now there is only home, to test whether it works as expected or not.
The public-facing web can not relay on the user’s language settings, as
the guest user has no way to set that. I would be happy to just use the
Accept-Language header for that, but apparently Google does not use that
header[0], and they give four alternatives: a country-specific domain,
a subdomain with a generic top-level domain (gTLD), subdirectories with
a gTLD, or URL parameters (e.g., site.com?loc=de).
Of the four, Google does not recommend URL parameters, and the customer
is already using subdirectories with the current site, therefor that’s
what i have chosen.
Google also tells me that it is a very good idea to have links between
localized version of the same resources, either with <link> elements,
Link HTTP response headers, or a sitemap file[1]; they are all
equivalent in the eyes of Google.
I have choosen the Link response headers way, because for that i can
simply “augment” ResponseHeader to automatically add these headers when
the response status is 2xx, otherwise i would need to pass down the
original URL path until it reaches the template.
Even though Camper is supposed to be a “generic”, multi-company
application, i think i will stick to the easiest route and write the
templates for just the “first” customer.
[0]: https://developers.google.com/search/docs/specialty/international/managing-multi-regional-sites
[1]: https://developers.google.com/search/docs/specialty/international/localized-versions
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