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
jordi fita mas