It is a separate relation, instead of having a field in campsite_type,
because not all campsite types allow dogs. I could have added a new
field to campsite_type, but then its values it would be meaningless for
campsites that do not allow dogs, and a nullable field is not a valid
solution because NULL means “unknown”, but we **do** know the price —
none.
A separate relation encodes the same information without ambiguities nor
null values, and, in fact, removed the dogs_allowed field from
campsite_type to prevent erroneous status, such as a campsite type that
allows dogs without having a cost — even if the cost is zero, it has to
be added to the new relation.
Besides the dynamic final cart, that was already handled by HTMx, i had
to check the maximum number of guests, whether the accommodation allows
“overflow”, whether dogs are allowed, and that the booking dates were
within the campground’s opening and closing dates.
I could do all of this with AlpineJS, but then i would have to add the
same validation to the backend, prior to accept the payment. Would not
make more sense to have them in a single place, namely the backend? With
HTMx i can do that.
However, i now have to create the form “piecemeal”, because i may not
have the whole information when the visitor arrives to the booking page,
and i still had the same problem as in commit d2858302efa—parsing the
whole form as is would leave guests and options field empty, rather than
at their minimum values.
One of the fieldsets in that booking form are the arrival and departure
dates, that are the sames we use in the campsite type’s page to
“preselect” these values. Since now are in a separate struct, i can
reuse the same type and validation logic for both pages, making my
JavaScript code useless, but requiring HTMx. I think this is a good
tradeoff, in fact.
I have to ask number and age ranges of hosts of guests for all campsite
types, not only those that have price options for adults, children, etc.
because i must compute the tourist tax for adults. These numbers will
be used to generate de rows for guests when actually creating the
booking, which is not done already.
To satisfy the campsite types that do have a price per guest, not only
per night, i had to add the prices for each range in the
campsite_type_cost relation. If a campsite type does not have price
per person, then that should be zero; the website then does not display
the price.
The minimal price for any campsite type is one adult for one night,
thus to compute the price i need at least the campsite type, the dates,
and the number of adults, that has a minimum of one. I changed the
order of the form to ask for these values first, so i can compute the
initial price as soon as possible. To help further, i show the
<fieldset>s progressively when visitors select options.
jordi fita mas