By chance, i found out that sometimes Go returned a Content-Type header
of text/plain for some responses to HTMx request. Go’s documentation
for http.ResponseWriter.Write sheds some light to this issue:
> If the Header does not contain a Content-Type line, Write adds a
> Content-Type set to the result of passing the initial 512 bytes of
> written data to DetectContentType.
http.DetectContentType has “sniff signatures” for the most common HTML
elements, such as `<BODY`, `<P`, or even `<!--`, but when the template
only has elements not in that list, the text “text sniff signature”
kicks in because the content does not contain binary data bytes, as
specified in [0], §7.1, step 9.
I can not change mustRenderTemplate’s wr parameter, and its callers’,
to be of type http.ResponseWriter because mustWriteInvoicePdf writes
the template to a pipe object, which is not of this type. Thus, i have
to resort to type assertion inside the method.
[0]: https://mimesniff.spec.whatwg.org/#identifying-a-resource-with-an-unknown-mime-type
They are almost the same as for the multiselect, except that it “clicks”
the option to “select” it, as this will trigger the replacement of the
<fieldset> with the whole product.
I had a lot of errors when trying to swap an element that has data-hx-on
attribute: it would tell me that it could not swap the bloody thing and
that t.onHandlers is not an iterable. I believe it also happened for
elements that did not have data-hx-on, but i am unsure at this point.
Apparently this is a bug introduced with version 1.9.0 of HTMx that as
of today is not yet fixed[0].
It seems that the problem that they keep the handlers created by
data-hx-on in an object, to be able to remove them afterward, but they
were looping the object with for(… of …) instead of for(… in …).
They will surely fix it in time, but since they will release a new
version, i have decided to change the minified code for now, as there
is no danger of replacing it with the new version—different file names.
[0]: https://github.com/bigskysoftware/htmx/issues/1368
I mainly did it for the new hx-on attribute, to click the update
button on recompute, but it does not seem to work as i think it does.
Anyway, there are some fixed bugs.
From the release announcement[0]:
## New Features
* Support for view transitions, based on the experimental View
Transitions API currently available in Chrome 111+ and coming to
other browsers soon.
* Support for “naked” hx-trigger attributes, where an hx-trigger is
present on an element that does not have an hx-get, etc. defined on
it. Instead, it will trigger the new htmx:triggered event, which
can be responded to via your preferred scripting solution.
* Support for generalized inline event handling via the new hx-on
attribute, which addresses the shortcoming of limited onevent
properties attributes in HTML.
## Improvements & Bug fixes
* A memory leak fix by @croxton
[0]: https://htmx.org/posts/2023-04-11-htmx-1-9-0-is-released/
The product search returns a list of products using its slug as the
“external key”, because i do not want people seeing the id in links,
and the search product list is just a different rendering of the product
index table.
However, now i had two almost identical select queries for product,
one using the product_id and the other its slug, the former intended for
the form to select products using checkboxes—the one non-JavaScript
users see—and the latter for the product search.
Using the slug in both forms i can now simplify the code and have a
single query.
With Oriol agreed that adding or editing invoices, products, and
contacts is not just a “user interruption” but the main flow of the
program, and, as such, it is not correct to use dialogs for these.
More importantly, it was harder to concentrate, specially with the more
involved form of invoices, because of all the “noise” behind the dialog.
This is for “free products”, where the user adds an invoice row, does
not select a product from the search, and clicks the update button.
Numerus should select “appropriate” values for those that are left
unspecified.
I also no longer require the product_id to be an integer; if it is
empty, then it is assumed to be a “free product”.
I actually find more comfortable to select the product from the list
presented up until now, but this is mostly because i have very few
products and the list is not too long, so the idea is that with
JavaScript we will dynamically add an empty product row to the invoice
and then use the name field to search the product by name.
I have the feeling that i am doing something wrong because i ended up
with a lot of HTMx attribute for what i feel is not that much work,
but for now it will work.
I have added the `Is` field to `InputField` in order to include the `id`
attribute to the HTML element, because the HTMLAttributes are attached
to the `input`, not the `div`, and i felt like this one should also be
a custom element based on div, like all the others.
These is not yet any keyboard control to select the search results.
I am not happy with having the search of products in a different URL
than the index, specially since they use the exact same SQL query and
ProductFilter struct, but i did not know how else ask for a different
representation without resorting to the more complicated MIME types.
I need a way to search products by name in the invoice form, when the
user adds or changes a product. Since this is something that i have to
add too to the product list, i added it now so the function will already
be ready.
I was using the exact same form from edit and new pages of invoice,
which is not too bad considering it won’t change very often, but i now
want to be able to add new empty product lines with the add product
button, and i will need to have a template for that form, which would
mean a third copy.
We are going to allow invoices with products that are not (yet) inserted
into the products table.
We always allowed to have products in invoices with a totally different
name, description, price, and whatnot, but until now we had the product
id in these invoice lines for statistics purposes.
However, Oriol raised the concern that this requires for the products
to be inserted before we can create an invoice with them, and we do not
plan to have a “create product while invoicing” feature, thus it would
mean that people would need to cancel the new invoice, create the new
product, and then start the invoice again from scratch.
The compromise is to allow products in the invoice that do not have a
product_id, meaning that at the time the invoice was created they were
not (yet) in the products table. Oriol sees this stop-invoice-create-
product issue more important than the accurate statistics of product
sales, as it will probably be only one or two units off, anyway.
I did not want to allow NULL values to the invoice product’s product_id
field, because NULL means “dunno” instead of “no product”, so i had to
split that field to a separate table that relates an invoice product
with a registered product.
We have reconsidered the toggle thing and instead moved the selection
into a little menu on top of the input, like the input’s label does à
la Material Design.
I just moved the checkboxes into a new details, that works as a menu,
but i had to add the type="search" to the existing input in the tags
field, or the CSS would style the checkboxes as well.
I do not do anything when the checkbox selection changes because that
already triggers a POST to the server that returns the new HTML with
the checkbox changed, and the JavaScript only has to retrieve that new
structure, exactly as it does in the initial rendering.
Since we want to add a little description to the options, i no longer
can use the same SelectOption in ToggleField, even though i could have
reused the Group element, but that felt wrong.
I realized that using a select for just two, short, options is overkill:
the select and its options use a lot more real state than the two
radios, which can have tooltips (not yet, though).
Since i am going to replace this field with a custom element that has
a toggle-like aspect, i already added the is="numerus-toggle" attribute
and use it for stying the non-JavaScript field.
This is because Oriol thinks that there may be cases where you want to
search invoices and such that have any of the selected labels, not all
of them, so we agreed on adding an option to choose.
The idea is that it will be a toggle, but this requires JavaScript and
this commit adds it as a dropdown as a first non-JavaScript step.
Apparently i was only testing that control with tab, because clicking
on any other non-focusable element (e.g., a table row) it did not add
the new tag and would not dispatch the “numerus-tag-out” custom element,
which is why i have seen it now.
This is equivalent to AlpineJS’s @click.outside, and i was already using
it for the multiselect dropdown. The isConnected check is because i
probably found some cases in the dropdown’s handler, but i can not
remeber now, but since AlpineJS does it too, i guess it is important.
I use the same pattern as HTMx’s “Click to Edit” example[0], except that
my edit form is triggered by submit and by focus out of the tags input.
I could not, however, use the standard focus out event because it would
also trigger when removing a tag with the mouse, as for a moment the
remove button has the focus and the search input dispatches a bubbling
focusout. I had to resort to a custom event for that, but i am not
happy with it.
The autofocus attribute seems to do nothing in this case, so i need to
manually change the focus to the new input with JavaScript. However,
this means that i can not use the same input ID for all the forms
because getElementById would always return the first in document order,
changing the focus to that same element and automatically submit the
form due to focus out. That’s why in this form i append the invoice’s
slug to the input’s ID.
Finally, this is the first time i am using an HTMx-only solution and i
needed a way to return back just the HTML for the <td>, without <title>,
breadcrumbs, or <dialog>. In principle, the template would be the
“layout”, but then i would need to modify everything to check whether
the template file is empty, or something to that effect, so instead i
created a “standalone” template for these cases.
[0]: https://htmx.org/examples/click-to-edit/
For some reason, i was looking at the value of the focus’ **target**,
which is not my search field at all, but whatever control the focus
changes **to**. It that new control is an input with value, then it
created a new tag with whatever my search field had, which could be the
empty string.
I realized that the event handlers that i was setting when creating the
tags input and the multi-select controls were not removed just because
these elements are no longer in the document, and kept firing again and
again.
I no longer can use an anonymous function, because removeEventListener
would not match it with the one passed to addEventListener. I also have
to bind the handler to `this` in order to keep having access to the
object, and, again, can not do it in the call to addEventListener, or
i would get a different function each time.
I added the check to see if the element is connected inside the
connectedCallback because the documentation warns that this callback
“may be called once your element is no longer connected”[0], and i
understood it to mean that the connected and disconnected callbacks
could be called our of order, thus it would be possible to add event
listeners that would not be removed—again.
I am not actually sure where i have to do the same for the rest of the
“internal” events.
[0]: https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements#using_the_lifecycle_callbacks
This is mainly because i sometimes think that the tag is accepted just
because it is there in the input, but actually it is not being used at
all. I fear more people would do the same mistake.
It all started when i wanted to try to filter invoices by multiple tags
using an “AND”, instead of “OR” as it was doing until now. But
something felt off and seemed to me that i was doing thing much more
complex than needed, all to be able to list the tags as a suggestion
in the input field—which i am not doing yet.
I found this article series[0] exploring different approaches for
tagging, which includes the one i was using, and comparing their
performance. I have not actually tested it, but it seems that i have
chosen the worst option, in both query time and storage.
I attempted to try using an array attribute to each table, which is more
or less the same they did in the articles but without using a separate
relation for tags, and i found out that all the queries were way easier
to write, and needed two joins less, so it was a no-brainer.
[0]: http://www.databasesoup.com/2015/01/tag-all-things.html
This makes reload only the <main> portion of the page, instead of the
whole thing, which to me looks faster; haven’t really measured it.
Like with duplicate, i had to add the location query argument when
inside the view page in order to return back to the same page, not the
index.
Had to add a new hidden field to the form to know whether, when the
request is HTMx-triggered, to refresh the page, as i do when duplicating
from the index, or redirect the client to the new invoice’s view page,
but only if i was duplicating from that same page, not the index.
Since i now have to target main when redirecting to the view page, so
i had to add a location structure with the required json fields and all
that, when “refreshing” i actually tell HTMx to open the index page
again, which seems faster, now that i am used to boosted links.
Changed the invoice number field’s type to search to add the delete icon
on Chromium. Firefox does not add that icon, but i do not care; it is
still better that type="text".
Had to emit the change event to the numerus-tag field, otherwise the
form would not detect the change.
I also can not use keyup as a trigger because the changed modifier can
not be used in the <form>, as nothing ever changes, i do not know how to
trigger the form from children (i.e., data-hx-trigger on the <input>
does nothing), and i can not trigger for just any keyup, or i would
make the request even if they only moved the cursor with the arrow keys,
which is very confusing as Firefox resets the position (this may be due
the fact that i reload the whole <main>, but still).
This is for the unusual case of products without taxes, that PostgreSQL
by default would generate an array with a single null value in it, but
then pgx would not be able to set that null to the string variable.
Initially, this field was meant to be left almost always blank, except
for when we deleted invoiced and had to “replace” its number with a new
invoice; using the automatic numbering in this cas would not “fill in”
the missing number in the sequence.
However, we decide to not allow removing invoicer not edit their
numbers, therefore, if everything goes as planned, there should not be
any gap in the sequence, and that field is rendered useless.
Oriol suggested making it a read-only field, both for new and edit
forms, but i do not think it makes sense to have a field if you can not
edit it at all, specially in the new invoice dialog, where it would
always be blank. In the edit form we already show the number in the
title and breadcrumbs, thus no need for the read-only field as
reference.
I still keep a Number member to the form struct, but is now a string
(kind of “a read-only field”, in a way) and just to be written in the
title or breadcrumbs. I did not like the idea of adding a new SQL
query just for that value.
In this case i have to use the same id for the dialog content in all
pages because, for now, there are a couple of forms that need to replace
it on submit—the new/edit form and the product selection form.
Unfortunately, HTMx does not have support for `formaction` attribute at
this point, so i had to use the workaround described in [0].
[0] https://github.com/bigskysoftware/htmx/issues/623
Instead of using links in the invoice tags, that we will replace with a
“click-to-edit field”, with Oriol agreed to add a form with filters that
includes not only the tags but also dates, customer, status, and the
invoice number.
This means i now need dynamic SQL, and i do not think this belongs to
the database (i.e., no PL/pgSQL function for that). I have looked at
query builder libraries for Golang, and did not find anything that
suited me: either they wanted to manage not only the SQL query but also
all structs, or they managed to confuse Goland’s SQL analyzer.
For now, at least, i am using a very simple approach with arrays, that
still confuses Goland’s analyzer, but just in a very specific part,
which i find tolerable—not that their analyzer is that great to begin
with, but that’s a story for another day.
We agreed with Oriol that this link would only serve to confuse people.
I initially added the link because i thought it was a shame to have to
navigate to the contact section to look or change the info of a customer
that you have an invoice for in front of you. However, it makes little
sense to be able to edit the contact from both sections, and we do not
have a “view page” for contacts to link to, thus the removal.
Had to add the editProductPage because now i need to know the slug in
order to build the form’s action link. I also added the `ProductName`
field because it was less awkward than using `.Form.Name` everywhere.
Mostly, the same problem as before: if the document title does not
reflect the application’s state, it becomes useless when there are
multiple open tabs.
In this case, however, i do not know how to tell HTMx to restore the
title to how it was before opening the dialog without a new request to
the server, that makes no sense when the dialog was closed without any
change whatsoever. Thus, i do it with JavaScript on the client side.
With Oriol we agreed that products should have tags, too, and that the
“tag pool”, as it were, should be shared with the one for invoices and
contacts.
Had to add the `company_id` attribute in the `using` clause for `tag` in
`MustFillFromDatabase`, even though it’s not strictly necessary, because
then PostgreSQL does not know which `company_id` attribute use for the
join with `company`—the one from `product` or the one from `tag`.
With Oriol we agreed that contacts should have tags, too, and that the
“tag pool”, as it were, should be shared with the one for invoices (and
all future tags we might add).
I added the contact_tag relation and tag_contact function, just like
with invoices, and then realized that the SQL queries that Go had to
execute were becoming “complex” enough: i had to get not only the slug,
but the contact id to call tag_contact, and all inside a transaction.
Therefore, i opted to create the add_contact and edit_contact functions,
that mirror those for invoice and products, so now each “major” section
has these functions. They also simplified a bit the handling of the
VATIN and phone numbers, because it is now encapsuled inside the
PL/pgSQL function and Go does not know how to assemble the parts.
jordi fita mas