End a select's long value before its arrow, with an ellipsis

Where the browser has the customizable select, select.css made the
select `display: flex` with `text-overflow: ellipsis`, but the closed
select draws its value in a block of its user-agent shadow tree: a flex
item at its automatic minimum width that takes no `text-overflow` from
the select, and no author style reaches it (`display: block` on the
select does not help either). So a long option in a narrow field, or
at `size="sm"` and `xs`, ran on past the end padding under the arrow,
which `overflow: hidden` only clips at the select's edge. The native
select in Firefox cut the value at the padding with no ellipsis.

The view now gives the select a first child `<button type="button"
wire:ignore>` holding `<selectedcontent>`, the customizable select's own
copy of the chosen option, and select.css makes that the flex item that
shrinks and ends in an ellipsis; the native select takes `nowrap`,
`overflow: hidden` and the ellipsis on itself. `wire:ignore`, because a
Livewire render parses the server's empty element into the first
option's label and morphed it back over the chosen one. A browser
without the customizable select never renders the button; `type` keeps
it from being a form's default button.

A browser test measures the value against the arrow in md, sm, xs,
filled and icon selects 240px wide, and again after choosing another
option re-renders the component; it fails without the change in Chrome
and Firefox.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

resources/boost/skills/livewire-material-development/SKILL.md

@@ -671,7 +671,7 @@ M3 text fields. `variant`: `outlined` or `filled`; without it, `config('livewire
 - `<x-textarea>`: grows from `rows` (3) to `max-rows`, then scrolls; `:autogrow="false"` for a fixed, hand-resizable one; `counter`.
 - Width: M3 asks that a text field never span the full width of a large screen, so from `medium` (600px) every field stops at **40rem**; below that it fills its pane. A width rule of your own on its `class` (`max-inline-size: 24rem`) narrows or widens it, because your unlayered CSS outranks the package's, and `full` (on `<x-field>`, `<x-input>`, `<x-textarea>`) takes the bound off for a field that really is the width of its pane — a search row, an editor. `<x-search>`'s bar carries M3's own bound, 720px.
 - `counter` (on `<x-input>` and `<x-textarea>`) puts M3's character counter at the end of the supporting-text row, beside the hint or the error: `n/max`, counted on every keystroke against the field's own `maxlength`, and in the error colour once the value is past it. It needs `maxlength` — without one there is nothing to count against and nothing is drawn. It is said as "Character count, 5/20" from a polite region a second after typing stops.
-- `<x-select>`: native `<select>` (M3 menu where the browser supports customizable selects). `options` as `['id' => …, 'name' => …, 'disabled' => bool]`, `option-value`, `option-label`, `placeholder` + `placeholder-value`, or `<option>`s in the slot; `icon`, `size`.
+- `<x-select>`: native `<select>` (M3 menu where the browser supports customizable selects). `options` as `['id' => …, 'name' => …, 'disabled' => bool]`, `option-value`, `option-label`, `placeholder` + `placeholder-value`, or `<option>`s in the slot; `icon`, `size`. A value too long for the field ends before the arrow with an ellipsis; the customizable select draws it in a `<button>` holding `<selectedcontent>`, which the view renders as the select's first child.
 - `<x-file>`: native file input; errors from `photos` and `photos.*`. Show previews of what was chosen yourself.
 - `<x-field id="…" label="…" :messages="$messages">` wraps a custom control given `data-md-field-control`; only for controls the package does not have.
 

resources/css/components/select.css

@@ -9,6 +9,11 @@
  * while the list is open, and the arrow turns over. The open list itself is M3's menu, drawn by
  * components/menu.css.
  *
+ * A value too long for the field ends before the arrow with an ellipsis. The native select cuts its
+ * own text at its end padding; the customizable one draws the value in a box of its shadow tree
+ * that no author style reaches, so the view gives it a `<button>` holding `<selectedcontent>`, the
+ * browser's copy of the chosen option, and the ellipsis is drawn there.
+ *
  * The field's root carries `data-md-select`.
  */
 
@@ -22,7 +27,9 @@
     /* A select covers its whole field — out over the padding and the leading icon at
        the start, under the arrow to the end — and its own padding puts the value back
        where it was. So a press anywhere on the field opens it, and the list, which
-       the browser anchors to the select, is the field's width (components/menu.css). */
+       the browser anchors to the select, is the field's width (components/menu.css).
+       A value longer than the field is cut at that padding, with an ellipsis, rather
+       than running on under the arrow. */
     select[data-md-field-control] {
         --field-end: calc(var(--field-icon) + var(--field-gap) + var(--field-pad));
 
@@ -30,6 +37,9 @@
         cursor: pointer;
         margin-inline: calc(-1 * var(--field-start)) calc(-1 * var(--field-end));
         padding-inline: var(--field-start) var(--field-end);
+        white-space: nowrap;
+        overflow: hidden;
+        text-overflow: ellipsis;
     }
 
     select[data-md-field-control]:disabled {
@@ -52,6 +62,15 @@
             padding-block: 0;
             border-radius: 0;
             background: transparent;
+        }
+
+        /* The customizable select's value is `<selectedcontent>`, the only part of the
+           closed select an author style reaches: the box the browser draws otherwise
+           takes neither `text-overflow` nor a width from the select, and ran on under
+           the arrow. As the select's flex item it may shrink to the room left. */
+        select[data-md-field-control] selectedcontent {
+            flex: 1 1 0%;
+            min-width: 0;
             white-space: nowrap;
             overflow: hidden;
             text-overflow: ellipsis;

resources/views/components/select.blade.php

@@ -11,8 +11,9 @@
      `option-value` and `option-label` to read other keys, and a `placeholder` that becomes the
      first option, valued `placeholder-value` (empty by default). Or pass `<option>`s in the slot.
      `label`, `hint`, `icon`, `variant`, `size`; `full` takes the 40rem bound off a field its container already bounds. `class` and `style` land on the field's root, every
-     other attribute on the `<select>`. The field's root carries `data-md-select`; what a
-     select changes in the field's chrome is resources/css/components/select.css. --}}
+     other attribute on the `<select>`. A value too long for the field ends before the arrow with
+     an ellipsis. The field's root carries `data-md-select`; what a select changes in the field's
+     chrome is resources/css/components/select.css. --}}
 
 @props([
     'label' => null,
@@ -46,6 +47,12 @@
         @if ($messages !== [] || filled($hint)) aria-describedby="{{ $id }}-support" @endif
         data-md-field-control
     >
+        {{-- The customizable select draws the chosen option in `<selectedcontent>`, which select.css
+             cuts with an ellipsis before the arrow; a browser without it never renders the button.
+             `wire:ignore`, because the browser fills it: a render would put back the first option's
+             label, parsed from the server's HTML, or nothing. --}}
+        <button type="button" wire:ignore><selectedcontent></selectedcontent></button>
+
         @if (filled($placeholder))
             <option value="{{ $placeholderValue }}">{{ $placeholder }}</option>
         @endif