This is for new users that do not start using the application from the
beginning of the current fiscal year and, therefore, need to create
invoices starting from a specific number.
I had to change the constraint on the currval to allow zero, otherwise
it would not be possible to set 1 as the next number, because users
can also not delete the row.
With this button, it is no longer necessary to set the quantity to zero
to remove, at least not with JavaScript. This is why i am using Alpine:
to use x-cloak and hide it from non-JavaScript users.
Although, i wonder if it would not be better to use HTMx for that?
I tried this already when i started adding filters, but i tried to use
AlpineJS for that, and could not because it would reset the context each
time i submitted the filters, due to HTMx replacing the whole content.
I realized that the only thing i need is some “flag” to show and hide
the form with CSS. I do not even need AlpineJS for that, but i used it
anyway because then i can use the x-cloak thing to hidde the toggle
button for users with JavaScript disabled.
Similarly, the body by default has that “flag” set in the markup, and is
removed when AlpineJS is initialized, thus if JavaScript is disabled the
filters form is shown nevertheless.
I want the `white-space: pre` to preserve the newline characters that
users may have used, but this prevents line wrapping and long lines are
not confined within the page margins.
`pre-line` preserves the newlines, but collapses spaces and tabs, and
wraps long text, which is more what i want.
I was hit with a couple of bugs: hx-on not properly de-initializing,
with a workaround in 43fffb68 and properly fixed with version 1.9.2;
and elements with naked hx-trigger did not work with hx-boost, as i do
for the tag inline form, fixed in 1.9.1.
The other bug fixed in 1.9.1, play well with other libraries that also
use the window.onpopstate, did not affect me, i believe.
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/
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.
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.
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.
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).
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
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.
We do not have any design yet for errors and other notifications, so i
followed material design, for now, since we already kind of use their
input fields design.
This time i decided to use AlpineJS because there is not that much HTML
code, and the transitioning is way easier to do in AlpineJS than it
would be with plain JavaScript—not to mention the bugs i would
introduce.
This is more or less the same as a multiselect, except that now it
adds a list of string element that you write into the search element.
It is supposed to fetch a list of tag suggestions from the server, but i
have not implemented it yet.
What i really set off on was to refactor the multiselect’s x-data
context to a separate JavaScript file.
I did not see the need at first, thinking that it would not matter
because it was used only in a template and i was not duplicating the
code in my files. However, i then realized that having the context
in the template means the visitor has to download it each and every time
it accesses a form with a multiselect, even if nothing changed, and,
worse, it would download it multiple times if there were many
multiselect controls.
It makes more sense to put all that into a file that the browser would
only download and parse once, if the proper caching is set.
Once i realized that, it was a shame that AlpineJS has no way to do
the same for the HTML structure[0], for the exact same reasons: not
wanting to download many times the same extra <template> and other
markup required to build the control for JavaScript users. And then i
remembered that this is supposed to be custom element’s main selling
point.
At first i tried to create a shadow DOW to replace the <select> with
the same <div> and <ul> that i used with Alpine, but it turns out that
<select> is not one of the allowed elements that can have a shadow root
attached[0].
Therefore, i changed the custom element to extend the <div> for the
<select> and <label> instead—the same element that had the x-init
context—, but i would have to define or include all the styles inside
the shadow DOM, and bring the lang attribute, for it to look like it
did before. Out with the shadow DOM, and modify the <div>’s contents
instead.
At this point the code was so far removed from the declarative way that
AlpineJS promotes that i did not see much value on using it, except for
its reactivity. But, given that this is such a small component, at the
end decided to write it all in plain JavaScript.
It is more code, at least looking only at the code i had to write, but
i love how i only have to add an is="numerus-multiselect" attribute to
HTML for it to work.
[0]: https://github.com/alpinejs/alpine/discussions/1205
[1]: https://developer.mozilla.org/en-US/docs/Web/API/Element/attachShadow
Had to replace the tags <ul> with a div with an input, so that the
browser can focus the keywoard there. For now i do not have a
focus-within CSS rule because we do no yet have a style for focus
highlight.
I have replaced the template for-loop to fill the options with the
JavaScript equivalent for two reasons. The first is that GoLand is very
stupid and can not handle that templating code inside the JavaScript
function and complains of non-existing problemes all the time.
The second is that, taking advantage of the input, i now have filtering
of options and have to remove accents from the label and convert it to
lowercase into a separate property just for that. I could do that with
a Go function, but it is something that i also have to do for the
input’s value when it changes, therefore i am forced to use JavaScript
and, if i am already using it for one string, it makes no sense to have
duplicate functionality in Go code.
The control still has missing aria attributes, and the list of options
is not yet navigable with the keyboard.
I had in the product edit page only because it was easier to test there
while i was developing it, but it is something that should be done for
all select[multiple], of course.
I removed the whole x-cloak thing because i am not sure what would
happen if i do something wrong and Alpine can not initialize the
multiselect; probably show nothing to the user. Now it shows the
native select a fraction of a second, but if i fuck it up at least the
user can still use the app.
This was actually the (first) reason we added the tax classes: to show
them in columns on the invoice—without the class we would need a column
for each tax rate, even though they are the same tax.
The invoice design has the product total with taxes at the last column,
above the tax base, that i am not so sure about, but it seems that it
has not brought any problem whatsoever so far, so it remains as is.
Had to reduce the invoice’s font size to give more space to the table
or the columns would be right next to each other. Oriol also told me
to add more vertical spacing to the table’s footer.
Although it is possible to just print the invoice from the browser, many
people will not even try an assume that they can not create a PDF for
the invoice.
I thought of using Groff or TeX to create the PDF, but it would mean
maintaining two templates in two different systems (HTML and whatever i
would use), and would probably look very different, because i do not
know Groff or TeX that well.
I wish there was a way to tell the browser to print to PDF, and it can
be done, but only with the Chrome Protocol to a server-side running
Chrome instance. This works, but i would need a Chrome running as a
daemon.
I also wrote a Qt application that uses QWebEngine to print the PDF,
much like wkhtmltopdf, but with support for more recent HTML and CSS
standards. Unfortunately, Qt 6.4’s embedded Chromium does not follow
break-page-inside as well as WeasyPrint does.
To use WeasyPrint, at first i wanted to reach the same URL as the user,
passing the cookie to WeasyPrint so that i can access the same invoice
as the user, something that can be done with wkhtmltopdf, but WeasyPrint
does not have such option. I did it with a custom Python script, but
then i need to package and install that script, that is not that much
work, but using the Debian-provided script is even less work, and less
likely to drift when WeasyPrint changes API.
Also, it is unnecessary to do a network round-trip from Go to Python
back to Go, because i can already write the invoice HTML as is to
WeasyPrint’s stdin.
jordi fita mas
oriol carbonell pujolàs