feat(home): htmx lazy-load cover images

Replace the eager <img> on the home page with an htmx placeholder <figure>
that fetches a /cover-fragment endpoint when it scrolls into view
(hx-trigger="revealed"), so heavy cover bytes load only on demand.
Add spinner + settle-fade transition CSS, and load htmx.min.js on home.
This commit is contained in:
Pontoporeia
2026-09-18 16:26:36 +02:00
parent 541470b9bb
commit fc66b37801
9 changed files with 366 additions and 6 deletions
+3
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@@ -4,8 +4,11 @@
> Context: CSS waste strategy — full stream DEFERRED (tasks 10/u/w/x/y/z): unusedSymbols report showed only ~6.2KB/2.9% of 216KB reclaimable; pruning + per-page split parked (docs/css-split-analysis.md). #t (Interdit admin route) confirmed already implemented via /admin/media.php + media-viewer.php + recapitulatif link. No pending live tasks.
## In Progress
- [x] #cover-home-lazy-intersect-fix [!high] Fix lazy covers not loading after initial images. Root cause: home grid scrolls inside <main class="home-main"> (overflow-y:auto, body height:100vh flex), but htmx `revealed` listens to window scroll only — so below-fold covers never revealed. Fix: hx-trigger="intersect threshold:0.05 once" (IntersectionObserver works inside any scroll container). VERIFIED LIVE: progressive scroll loads covers 5→11→15→20→22/22 (before: stuck ~5). Committed fix(home): use intersect trigger.
- [x] #cover-image-webp-avif-serve-lite [!medium] Serve lightweight webp cover thumbnails instead of full-res PNG originals (~99% on worst cases). DONE VERIFIED LIVE 2026-08-31: `cwebp -resize 800 q80` sidecars (+ GD fallback for CMYK JPEGs) generated by ThesisFileHandler at upload (FilePond + legacy); /cover-fragment emits <picture> (webp source + original fallback); backfill scripts/generate-cover-webp.php + `just deploy-cover-webp`. PROD: tools installed (docs), 46/46 covers backfilled (44 cwebp + 2 GD/CMYK), app code deployed, /cover-fragment + /media?path=*.webp verified 200 image/webp 61KB (vs 15.8MB orig). AVIF dropped (no viable prod resize; WEBP sufficient). NOTE: just deploy-code's final nginx/permissions step needs sudo password (operational, pre-existing — not a regression).
## Pending
- [x] #home-htmx-lazy-cover-images [!medium] Add htmx lazyloading on home page cover images: `revealed`-triggered cover-fragment endpoint, swap-in `<img>`, settle fade CSS, load htmx on home
## Completed
- [x] #audit-all-docs-and [!high] Audit all docs/ and classify accurate vs stale
+29 -1
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@@ -78,7 +78,15 @@
height: 100%;
object-fit: cover;
display: block;
transition: transform 0.3s ease;
transition: transform 0.3s ease, opacity 300ms ease-in;
}
/* Cover thumbnails are served as a <picture> (WebP + fallback); keep the
wrapper block-level so the <img> fills the 4:3 figure. */
.home-body figure picture {
display: block;
width: 100%;
height: 100%;
}
.card:hover figure img,
@@ -97,6 +105,26 @@
font-size: var(--step-3);
}
/* HTMX lazy-loaded cover: spinner + settle fade-in (mirrors htmx
docs' `htmx-settling img` transition pattern). */
.card__cover-loading {
animation: card-cover-pulse 1.1s ease-in-out infinite;
}
@keyframes card-cover-pulse {
0%,
100% {
opacity: 0.3;
}
50% {
opacity: 1;
}
}
.home-body figure.htmx-settling img {
opacity: 0;
}
.card__media--gradient {
width: 100%;
aspect-ratio: 4 / 3;
+2
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@@ -157,6 +157,8 @@ class HomeController
// Layout
'currentNav' => '',
'extraCss' => ['/assets/dist/public.min.css'],
// htmx powers the `revealed` lazy-loaded cover images on this page
'extraJs' => ['/assets/js/vendor/htmx.min.js'],
'bodyClass' => 'home-body',
];
}
+109
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@@ -49,6 +49,13 @@ trait ThesisFileHandler
/** Cover image max size. */
private const MAX_COVER_SIZE = 20 * 1024 * 1024; // 20 MB
/**
* WebP cover-thumbnail tuning (served to the public home grid).
* `cwebp` must be installed on the server (see docs/environment.md).
*/
private const COVER_WEBP_MAX_WIDTH = 800; // px, tall-side kept proportional
private const COVER_WEBP_QUALITY = 80;
/** MIME types accepted for thesis files. */
private const ALLOWED_MIME_TYPES = [
'image/jpeg', 'image/png', 'image/gif', 'image/webp',
@@ -137,6 +144,104 @@ trait ThesisFileHandler
$mimeType
);
error_log("ThesisFileHandler: cover uploaded → $relPath");
$this->generateCoverWebp($targetPath);
}
/**
* Generate a small WebP cover thumbnail next to the original cover.
*
* Covers are uploaded as full-resolution PNG/JPEG and — on the public home
* grid — rendered into a small 4:3 card. Serving the original is wasteful
* (up to ~15 MB for a ~300 px card). `cwebp -resize` both downscales and
* re-encodes in one pass, typically cutting payload by ~95%+.
*
* The thumbnail is a plain sidecar file (`{prefix}_COUVERTURE.webp`); it is
* NOT registered in thesis_files. Consumption is via /media (webp MIME is
* already allowed) using the same storage-relative path with a .webp ext.
*
* @param string $sourcePath Absolute path to the uploaded cover.
*/
private function generateCoverWebp(string $sourcePath): void
{
if (!is_file($sourcePath) || !is_readable($sourcePath)) {
return;
}
$targetPath = preg_replace('/\.[a-z0-9]+$/i', '.webp', $sourcePath);
if ($targetPath === null || $targetPath === $sourcePath) {
return;
}
// Best-effort: never break the upload if transcoding is unavailable
// (no `cwebp`, PATH issues, etc.). A missing thumbnail simply makes the
// public grid fall back to the original via the <picture> fallback.
$cmd = sprintf(
'cwebp -quiet -resize %d 0 -q %d %s -o %s 2>/dev/null',
self::COVER_WEBP_MAX_WIDTH,
self::COVER_WEBP_QUALITY,
escapeshellarg($sourcePath),
escapeshellarg($targetPath)
);
$out = [];
$code = 0;
exec($cmd, $out, $code);
if ($code === 0 && is_file($targetPath)) {
@chmod($targetPath, 0644);
error_log('ThesisFileHandler: cover webp generated → ' . basename($targetPath));
return;
}
// cwebp can't read CMYK JPEGs ("Unsupported color conversion"); those
// are increasingly common as scanned-cover uploads. GD (php-gd) handles
// the CMYK→RGB conversion implicitly on decode, so fall back to it with
// the same resize + quality before giving up.
if ($this->generateCoverWebpWithGd($sourcePath, $targetPath)) {
error_log('ThesisFileHandler: cover webp generated (GD fallback) → '
. basename($targetPath));
return;
}
error_log("ThesisFileHandler: webp generation failed for cover (cwebp exit $code)"
. ' → ' . basename($targetPath));
}
/**
* GD-based WebP thumbnail generation (CMYK-JPEG fallback for cwebp).
*
* @param string $sourcePath Absolute path to the original cover.
* @param string $targetPath Absolute path to the .webp output.
* @return bool true on success.
*/
private function generateCoverWebpWithGd(string $sourcePath, string $targetPath): bool
{
if (!function_exists('imagecreatefromjpeg') || !function_exists('imagewebp')) {
return false;
}
$im = @imagecreatefromjpeg($sourcePath);
if ($im === false) {
return false;
}
$srcW = imagesx($im);
$srcH = imagesy($im);
$dstW = min(self::COVER_WEBP_MAX_WIDTH, $srcW);
$dstH = (int) round($srcH * $dstW / $srcW);
$tgt = imagecreatetruecolor($dstW, $dstH);
imagecopyresampled($tgt, $im, 0, 0, 0, 0, $dstW, $dstH, $srcW, $srcH);
$ok = imagewebp($tgt, $targetPath, self::COVER_WEBP_QUALITY);
imagedestroy($im);
imagedestroy($tgt);
if ($ok) {
@chmod($targetPath, 0644);
}
return $ok;
}
/**
@@ -979,6 +1084,10 @@ trait ThesisFileHandler
);
error_log("ThesisFileHandler: $queueKey uploaded (filepond) → $targetName");
if ($queueKey === 'cover') {
$this->generateCoverWebp($targetPath);
}
$this->cleanupFilePondTmp($fileId);
}
+33
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@@ -117,6 +117,39 @@ class Dispatcher
};
}
// /cover-fragment (HTMX lazy-load: returns just the cover markup.
// Consumed by the home page's `revealed`-triggered placeholders — the
// heavy image bytes are fetched only when a card scrolls into view.
//
// Prefers the small WebP thumbnail (same storage-relative path, .webp
// ext) when present, else falls back to the original via <picture>.
if ($path === '/cover-fragment' || $path === '/cover-fragment.php') {
return static function (): void {
$coverPath = $_GET['path'] ?? '';
// Same strict whitelist as MediaController: no traversal, no junk.
if (
$coverPath === ''
|| !preg_match('#^[a-zA-Z0-9/_\-.]+$#', $coverPath)
) {
http_response_code(400);
exit;
}
$orig = '/media?path=' . urlencode($coverPath);
$webpPath = preg_replace('/\.[a-z0-9]+$/i', '.webp', $coverPath);
echo '<picture>'
. '<source type="image/webp" srcset="'
. htmlspecialchars('/media?path=' . urlencode((string) $webpPath), ENT_QUOTES, 'UTF-8')
. '">'
. '<img src="'
. htmlspecialchars($orig, ENT_QUOTES, 'UTF-8')
. '" alt="Couverture" loading="lazy">'
. '</picture>';
};
}
// /maintenance.php
if ($path === '/maintenance' || $path === '/maintenance.php') {
return function () {
+8 -4
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@@ -17,10 +17,14 @@
$thumb = $coverMap[$item['id']] ?? null;
?>
<?php if ($thumb): ?>
<figure>
<img src="/media?path=<?= urlencode($thumb) ?>"
alt="Couverture — <?= htmlspecialchars($item['title']) ?> par <?= htmlspecialchars($item['authors'] ?? '') ?>"
loading="lazy">
<figure
hx-get="/cover-fragment?path=<?= urlencode($thumb) ?>"
hx-trigger="intersect threshold:0.05 once"
hx-swap="innerHTML"
aria-busy="true">
<div class="card__media--placeholder" role="status">
<span class="card__cover-loading">…</span>
</div>
</figure>
<?php else: ?>
<div class="card__media--gradient"
+20 -1
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@@ -16,6 +16,23 @@ archived at [`spec-sheet.md`](archive/spec-sheet.md)).
| **App user** | `www-data`, group `xamxam` |
| **Node.js** | *Not required on the server* — assets are built locally and rsync'd |
## Image transcoding tooling (installed 2026-08-31)
Installed on the production server to generate lightweight WebP/AVIF cover
thumbnails (home-page cover grid — up to ~95% payload reduction):
- `php-gd` — PHP GD extension (WebP/AVIF encode/resize for on-the-fly serving)
- `webp` — provides the `cwebp` CLI (WebP conversion)
- `libavif-bin` — provides the `avifenc` CLI (AVIF conversion)
Install on any environment that must serve cover thumbnails:
```bash
sudo apt-get install php-gd webp libavif-bin
```
Consumed by the cover-thumbnail pipeline (see `docs/...` once implemented).
## PHP (≥ 8.4)
Declared in `composer.json` (`"php": ">=8.4"`, platform lock `8.4`).
@@ -36,7 +53,9 @@ Verified present in the production `php -m` output and on the FPM pool:
- `session` — admin auth + CSRF (see [`security.md`](security.md))
- `sodium` — `Crypto` (libsodium) for encrypted fields (SMTP password)
- `zlib` / `phar` — Composer autoload + PHAR-based tooling
- `gd` — not used directly, present transitively (image handling is `finfo`)
- `gd` — **intentionally installed** (`php-gd`, 2026-08-31) for cover-image
transcoding to WebP/AVIF; resize/encode derivations for the home-page cover
grid. Not used for MIME validation (that is `finfo`).
- `fileinfo` — upload MIME validation (`finfo`)
- `calendar`, `ctype`, `filter`, `hash`, `tokenizer`, `xml`, `libxml` — PHP core
extensions, present by default
+10
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@@ -176,6 +176,16 @@ deploy-migrate:
ssh xamxam "cd /var/www/xamxam && REPO_ROOT=/var/www/xamxam bash /tmp/migrate.sh"
ssh xamxam "rm -f /tmp/migrate.sh"
[group('deploy')]
deploy-cover-webp dry_run='':
# Backfill small WebP cover thumbnails on the server (idempotent).
# Dry-run by default; pass --no-dry-run to actually generate. Runs as the
# SSH user (member of the xamxam group, dirs are setgid group-writable) so
# no sudo is needed. Deploy as www-data if group-write ever changes.
rsync -v scripts/generate-cover-webp.php xamxam:/tmp/generate-cover-webp.php
ssh xamxam "cd /var/www/xamxam && php /tmp/generate-cover-webp.php {{dry_run}}"
ssh xamxam "rm -f /tmp/generate-cover-webp.php"
[group('deploy')]
deploy-env:
#!/usr/bin/env bash
+152
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@@ -0,0 +1,152 @@
#!/usr/bin/env php
<?php
/**
* generate-cover-webp.php — Backfill small WebP cover thumbnails.
*
* Covers are uploaded as full-resolution PNG/JPEG but rendered into a small
* 4:3 card on the public home grid. Serving the original is wasteful — a single
* cover can be ~15 MB. This scans every `*_COUVERTURE.*` file under the storage
* root and, for any that lacks a `.webp` sibling, downscales + re-encodes it in
* one `cwebp -resize` pass (typically ~95%+ smaller, to ~800px wide @ q80).
*
* Idempotent: skips covers that already have a `.webp` sibling. Safe to re-run.
*
* Usage:
* php scripts/generate-cover-webp.php # dry-run (list pending)
* php scripts/generate-cover-webp.php --no-dry-run # actually generate
* COVER_WEBP_WIDTH=1000 COVER_WEBP_QUALITY=85 php scripts/generate-cover-webp.php --no-dry-run
*
* Requires `cwebp` on PATH (see docs/environment.md). Exit code 0 on success,
* 1 on error.
*/
declare(strict_types=1);
// Resolve APP_ROOT robustly. In production the app code is deployed flat under
// /var/www/xamxam/ (src/, storage/, templates/ at the root, no app/ subdir).
$prodRoot = '/var/www/xamxam';
if (is_dir($prodRoot . '/src') && is_file($prodRoot . '/src/Database.php')) {
define('APP_ROOT', $prodRoot);
$storageRoot = $prodRoot . '/storage';
} else {
define('APP_ROOT', dirname(__DIR__) . '/app');
$storageRoot = APP_ROOT . '/storage';
}
$dryRun = !in_array('--no-dry-run', $argv, true);
// Tuning (mirrors ThesisFileHandler::generateCoverWebp defaults).
$maxWidth = (int) (getenv('COVER_WEBP_WIDTH') ?: 800);
$quality = (int) (getenv('COVER_WEBP_QUALITY') ?: 80);
if ($maxWidth < 1) {
$maxWidth = 800;
}
if ($quality < 0 || $quality > 100) {
$quality = 80;
}
if (!is_dir($storageRoot) || !is_readable($storageRoot)) {
fwrite(STDERR, "[generate-cover-webp] storage root not readable: $storageRoot\n");
exit(1);
}
if (!function_exists('exec')) {
fwrite(STDERR, "[generate-cover-webp] exec() is disabled; cannot run cwebp.\n");
exit(1);
}
// Recursively collect cover files.
$covers = [];
$rii = new RecursiveIteratorIterator(
new RecursiveDirectoryIterator($storageRoot, FilesystemIterator::SKIP_DOTS)
);
foreach ($rii as $entry) {
if (!$entry->isFile()) {
continue;
}
$name = $entry->getFilename();
// Only source covers (original upload) count as inputs; the generated
// `.webp` sidecars must NOT be re-scanned as sources.
if (!preg_match('/_COUVERTURE\.[a-z0-9]+$/i', $name) || str_ends_with($name, '.webp')) {
continue;
}
$covers[] = $entry->getPathname();
}
sort($covers);
$pending = [];
$existing = 0;
foreach ($covers as $sourcePath) {
$webpPath = preg_replace('/\.[a-z0-9]+$/i', '.webp', $sourcePath);
if ($webpPath !== null && is_file($webpPath)) {
$existing++;
continue;
}
$pending[] = $sourcePath;
}
$skipped = 0;
if ($dryRun) {
foreach ($pending as $p) {
printf("DRY-RUN → %s (%d bytes)\n", $p, (int) filesize($p));
}
printf(
"Found %d cover file(s): %d already have a .webp thumbnail, %d pending.\n",
count($covers),
$existing,
count($pending)
);
echo "Re-run with --no-dry-run to generate them.\n";
exit(0);
}
foreach ($pending as $sourcePath) {
$targetPath = preg_replace('/\.[a-z0-9]+$/i', '.webp', $sourcePath);
$cmd = sprintf(
'cwebp -quiet -resize %d 0 -q %d %s -o %s 2>/dev/null',
$maxWidth,
$quality,
escapeshellarg((string) $sourcePath),
escapeshellarg((string) $targetPath)
);
exec($cmd, $_, $code);
$ok = $code === 0 && $targetPath !== null && is_file($targetPath);
// cwebp can't read CMYK JPEGs; fall back to GD (php-gd) which handles
// CMYK->RGB on decode, same resize + quality.
if (!$ok && function_exists('imagecreatefromjpeg') && function_exists('imagewebp')) {
$im = @imagecreatefromjpeg((string) $sourcePath);
if ($im !== false && $targetPath !== null) {
$srcW = imagesx($im);
$srcH = imagesy($im);
$dstW = min($maxWidth, $srcW);
$dstH = (int) round($srcH * $dstW / $srcW);
$tgt = imagecreatetruecolor($dstW, $dstH);
imagecopyresampled($tgt, $im, 0, 0, 0, 0, $dstW, $dstH, $srcW, $srcH);
$ok = imagewebp($tgt, $targetPath, $quality);
imagedestroy($im);
imagedestroy($tgt);
if ($ok) {
@chmod($targetPath, 0644);
}
}
}
if ($ok && $targetPath !== null && is_file($targetPath)) {
@chmod($targetPath, 0644);
printf("✓ %s (%d → %d bytes)\n", basename($targetPath), (int) filesize($sourcePath), (int) filesize($targetPath));
} else {
printf("✗ failed: %s (cwebp exit %d)\n", (string) $sourcePath, $code);
$skipped++;
}
}
printf(
"Generated %d WebP thumbnail(s); %d failed. %d already present.\n",
count($pending) - $skipped,
$skipped,
$existing
);
exit($skipped > 0 ? 1 : 0);