This allows to import an Excel file exported from Holded, because it is
our own user case. When we have more customers, we will give out an
Excel template file to fill out.
Why XLSX files instead of CSV, for instance? First, because this is the
output from Holded, but even then we would have more trouble with CSV
than with XLSX because of Microsoft: they royally fucked up
interoperability when decided that CSV files, the files that only other
applications or programmers see, should be “localized”, and use a comma
or a **semicolon** to separate a **comma** separated file depending on
the locale’s decimal separator.
This is ridiculous because it means that CSV files created with an Excel
in USA uses comma while the same Excel but with a French locale expects
the fields to be separated by semicolon. And for no good reason,
either.
Since they fucked up so bad, decided to add a non-standard “meta” field
to specify the separator, writing a `sep=,` in the first line, but this
only works for reading, because saving the same file changes the
separator back to the locale-dependent character and removes the “meta”
field.
And since everyone expects to open spreadsheet with Excel, i can not
use CSV if i do not want a bunch of support tickets telling me that the
template is all in a single line.
I use an extremely old version of a xlsx reading library for golang[0]
because it is already available in Debian repositories, and the only
thing i want from it is to convert the convoluted XML file into a
string array.
Go is only responsible to read the file and dump its contents into a
temporary table, so that it can execute the PL/pgSQL function that will
actually move that data to the correct relations, much like add_contact
does but in batch.
In PostgreSQL version 16 they added a pg_input_is_valid function that
i would use to test whether input values really conform to domains,
but i will have to wait for Debian to pick up the new version.
Meanwhile, i use a couple of temporary functions, in lieu of nested
functions support in PostgreSQL.
Part of #45
[0]: https://github.com/tealeg/xlsx
The same as for invoices: to allow people to have their own numbering
scheme, and for these that start using the program in the middle of the
current year.
I have moved everything into a different file, even though it is related
to “db”, because it was starting to get a bit ugly.
Apparently i was doing too much work and had to read the code to
understand what i was supposed to do, because pgtypes’ documentation,
as all other projects from the same author, is almost non-existent.
I needed to add binary encoding function for the new_invoice_product
type, and currently it is not correct: i hardcoded the OID values, but
they are going to be different on a different database.
I am going to add similar functions for invoices, as i will need to
add the taxes for their products and their own taxes, thus the Go code
will begin to be “too much work” and i feel better if that is in
PL/pgSQL.
If i have these functions for invoices, there is no point on having to
do almost the same work, albeit less, for products.
It seems that we do not agree en whether the IRPF tax should be
something of the product or the contact, so we decided to make the
product have multiple taxes, just in case, and if only one is needed,
then users can just select one; no need to limit to one.
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.
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.
The whole application will need the same search_path, so it is wasteful
to do that in each handler.
It is possible to pass the search path as a parameter to the database’s
connection string, but then everyone would need to remember to do that,
and update the configuration in case i add another schema.
Similarly, i need to change the user’s role to match her
permissions—which are not in yet—, but this time i need it each time a
handler requests a connection from the pool, because each time the
connection is returned to the pool i reset the role back to the initial,
that hopefully will be authenticator.
jordi fita mas