We want to show the percentage of the tax as columns in the invoice,
but until now it was not possible to have a single VAT column when
products have different VAT (e.g., 4 % and 10 %), because, as far
as the application is concerned, these where ”different taxes”. We
also think it would be hard later on to compute the tax due to the
government.
So, tax classes is just a taxonomy to be able to have different names
and rates for the same type of tax, mostly VAT and retention in our
case.
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.
This is not yet necessary, but the empty label is because i do not want
to select a default tax for products—at least, not without a setting for
it.
Since i need to add the required attribute now to select, because
otherwise the browser would allow sending that empty value, i did not
want to do it unconditionally, just in case.
I do not want to use floats in the Go lang application, because it is
not supposed to do anything with these values other than to print and
retrieve them from the user; all computations will be performed by
PostgreSQL in cents.
That means i have to “convert” from the price format that users expect
to see (e.g., 1.234,56) to cents (e.g., 123456) and back when passing
data between Go and PostgreSQL, and that conversion depends on the
currency’s decimal places.
At first i did everything in Go, but saw that i would need to do it in
a loop when retrieving the list of products, and immediately knew it was
a mistake—i needed a PL/pgSQL function for that.
I still need to convert from string to float, however, when printing the
value to the user. Because the string representation is in C, but i
need to format it according to the locale with golang/x/text. That
package has the information of how to correctly format numbers, but it
is in an internal package that i can not use, and numbers.Digit only
accepts numeric types, not a string.
Our company is a kind-of contact, although it does not appear in the
contact section, thus i could embed the contact form inside the tax
details form to reuse all the common fields.
I implemented the Valuer and Scanner interfaces to InputField and
SelectField for better passing values between the database and Go. I
had a conflict with the Value name and renamed the struct member to Val.
I also had to change the attributes array to be of type
template.HTMLAttr or html/template would replace `form="newtax"`
attribute to `zgotmplz="newtax"` because it deems it “unsafe”. I do
not like having to use template.HTMLAttr when assigning values, but
i do not know what else i can do now.
I have been thinking about that, and it does not make that much sense to
have the titles in the Go source anymore: most of them are static text
that i have to remember to set in the controller each time, and when
the time come i have to face a dynamic title i am sure i will manage
with only the template capabilities—worst comes worst, i can always
define a function.
On the other hand, there is no way i can define a template without its
title and i know that everytime that template is used, no matter what
controller rendered it, it will always have that title.
At first we thought that a regular text field would do, because we were
afraid that a dropdown would be worse from the point of view of user
experience, but then we realized that we need the country code for VAT
and phone validation, and we can not expect users to input that, of
course.
I had to add the first “i18n table” to the database with the name of all
countries in both Catalan and Spanish and Catalan; English is the
default. For now i think i do not need a view that would select the
name based on the locale of the current request, because currently i do
not plan on adding any other such table —the currency uses the code and
the symbol, thus no need for localization.
However, now i need the language tag from the locale in order to get the
correct translation, and gotext does not give me any way to access the
inner language. Thus the need for our Locale type.
I do not have more time to update the update to the company today, but i
believe this is already a good amount of work for a commit.
The company is going to be used for row level security, as users will
only have access to the data from companies they are granted access, by
virtue of being in the company_user relation.
I did not know how add a row level security policy to the company_user
because i needed the to select on the same relation and this is not
allowed, because it would create an infinite loop.
Had to add the vat, pg_libphonenumber, and uri extensions in order to
validate VAT identification numbers, phone numbers, and URIs,
repectively. These libraries are not in Debian, but i created packages
for them all in https://dev.tandem.ws/tandem.
jordi fita mas