Similar to the profile form, the login form now parses and validates
itself, with the InputField structs that the templates expect.
I realized that i was doing more work than necessary when parsing fields
fro the profile form because i was repeating the operation and the field
name, so now it is a function of InputField.
This time i needed extra attributes for the login form. I am not sure
that the Go source code needs to know about HTML attributes, but it was
the easiest way to pass them to the template.
This is for security, just in case two users have the same cookie,
althought it is unlikely, but nevertheless less guessable.
I also need to refresh the cookie when the user changes their email
address, because it is liked toghether. It does mean that it will
logout from everywhere else, but i can not do anything about that.
I want this so that the Go application does not need to know the exact
details of the settings that the database sets when applying the cookie;
it just needs to select from the user_profile that already knows this.
Also, that way i can get the user’s language from its profile with a
single select, without having to check whether we are guest or
authenticated.
With that, i can skip the content negotiation if the user already told
us what language they want.
Had to call xgettext on Go source files because now the title comes from
there, as i assume i will have titles like "Invoice #INVxxxx" that have
to come from the database that the template does not know.
Since users do not have access to the auth scheme, i had to add a view
that selects only the data that they can see of themselves (i.e., no
password or cookie).
I wanted to use the `request.user.id` setting that i set in
check_cookie, but this would be bad because anyone can change that
parameter and, since the view is created by the owner, could see and
*change* the values of everyone just by knowing their id. Thus, now i
use the cookie instead, because it is way harder to figure out, and if
you already have it you can just set to your browser and the user is
fucked anyway; the database can not help here.
I **am** going to use the user id in row level security policies, but
not the value coming for the setting but instaed the one in the
`user_profile`, since it already is “derived” from the cookie, that’s
why i added that column to the view.
The profile includes the language, that i do not use it yet to switch
the locale, so i had to add a relation of the available languages, for
constraint purposes. There is no NULL language, and instead i added the
“Undefined” language, with ‘und’ tag’, to represent “do not know/use
content negotiation”.
The languages in that relation are the same i used to have inside
locale.go, because there is no point on having options for languages i
do not have the translation for, so i now configure the list of
available languages user in content negotiation from that relation.
Finally, i have added all font from RemixIcon because that’s what we
used in the design and i am going to use quite a lot of them.
There is duplication in the views; i will address that in a different
commit.
I did not like the idea that it was the Go server who should set values
such as request.user or set the role, because this is mostly something
that only the database wants for itself, such as when calling logout. I
am also planning to use these setings for row security with the user’s
id, that the Go application has no need for, but with the current
approach i would need to return it from check_cookie so that it can
return it back to the database when acquiring the connection.
I would have used the same function to set the settings and the role,
but security definer functions—obviously in retrospect—can not set the
role, because then could switch to any role of the user that defined the
function, not the roles they are member of. Thus, a new function.
I did not want to do that every time i needed the database connection
within the same request, because it would perform the same operations
each time—it is the same cookie, afterall—, so new connections are
request scoped and passed along in the context.
I had to choose between [1], [2], and [3].
As far as i could find, [1] is not easy to work with templates[4] and at
the moment is not maintained[5].
Both [2] and [3] use the same approach to be used from within templates:
you have to define a FuncMap with template functions that call the
message catalog. Also, both libraries seems to be reasonably
maintained, and have packages in Debian’s repository.
However, [2] repeats the same mistakes that POSIX did with its
catalogs—using identifiers that are not the strings in the source
language—, however this time the catalogs are written in JSON or YAML!
This, somehow, makes things worse….
[3], the one i settled with, is fine and decently maintained. There are
some surprising things, such as to be able to use directly the PO file,
and that it has higher priority over the corresponding MO, or that the
order of parameters is reversed in respect to gettext. However, it uses
a saner format, and is a lot easier to work with than [3].
The problem, of course, is that xgettext does not know how to find
translatable strings inside the template. [3] includes a CLI tool
similar to xgettext, but is not a drop-in replacement[6] and does not
process templates.
The proper way to handle this would be to add a parser to xgettext, but
for now i found out that if i surround the call to the translation
functions from within the template with parentheses, i can trick
xgettext into believing it is parsing Scheme code, and extracts the
strings successfully—at least, for what i have tried. Had to add the
keyword for pgettext, because Schemed does not have it, but at least i
can do that with command line parameters.
For now i left only Spanish and Catalan as the two available languages,
even though the source text is written in English, because that way i
can make sure i do not leave strings untranslated.
[1]: https://golang.org/x/text
[2]: https://github.com/nicksnyder/go-i18n
[3]: https://github.com/leonelquinteros/gotext
[4]: https://github.com/golang/go/issues/39954
[5]: https://github.com/golang/go/issues/12750
[6]: https://github.com/leonelquinteros/gotext/issues/38
At first i thought that i would need to implement sessions, the ones
that keep small files onto the disk, to know which user is talking to
the server, but then i realized that, for now at least, i only need a
very large number, plus the email address, to be used as a lookup, and
that can be stored in the user table, in a separate schema.
Had to change login to avoid raising exceptions when login failed
because i now keep a record of login attemps, and functions are always
run in a single transaction, thus the exception would prevent me to
insert into login_attempt. Even if i use a separate procedure, i could
not keep the records.
I did not want to add a parameter to the logout function because i was
afraid that it could be called from separate users. I do not know
whether it is possible with the current approach, since the settings
variable is also set by the same applications; time will tell.
jordi fita mas