Guard no-JS file uploads: disabled filepond_mode by default, server-side fallback

The partage/admin form had a hardcoded filepond_mode=1 hidden input,
so without JavaScript the server always entered the FilePond async
path — which found no hex IDs and silently dropped all files.

Three-layer fix:
1. HTML: filepond_mode input starts disabled with value=0; JS enables
   it and sets value=1 on DOMContentLoaded (and after HTMX swaps).
   Disabled inputs aren't submitted → server gets no filepond_mode
   → naturally falls to legacy  path.
2. JS: enableFilepondMode() called on page load and hx:afterSwap so
   FilePond-enhanced forms always send filepond_mode=1.
3. Server (defense-in-depth): ThesisFileHandler::hasFilePondQueueData()
   scans POST['queue_file'] for 32-char hex IDs; ThesisCreateController
   and ThesisEditController use it alongside filepond_mode, so even if
   the flag somehow arrives without async upload IDs, the  path
   takes over.

TODO.md

@@ -52,8 +52,8 @@ Reference: Assessment against progressive-enhancement / WCAG-AA / "never lose da
 **Current state:** `form.php` hardcodes `<input type="hidden" name="filepond_mode" value="1">`. Without JS, no `queue_file[]` hidden inputs are populated → server gets `filepond_mode=1` with empty queue → all files silently dropped. The form is supposed to work without JS.
 
 **To do:**
-- [ ] Change the hidden input to `<input type="hidden" name="filepond_mode" value="0" disabled>` by default; JS enables it and sets `value="1"` on DOMContentLoaded
+- [x] Change the hidden input to `<input type="hidden" name="filepond_mode" value="0" disabled>` by default; JS enables it and sets `value="1"` on DOMContentLoaded
-- [ ] Add server-side fallback in `ThesisCreateController::submit()` and `ThesisEditController::save()`: when `filepond_mode=1` but no `queue_file` data is present, fall through to the legacy `$_FILES` path
+- [x] Add server-side fallback in `ThesisCreateController::submit()` and `ThesisEditController::save()`: when `filepond_mode=1` but no `queue_file` data is present, fall through to the legacy `$_FILES` path
 - [ ] Test end-to-end: submit the partage form with JS disabled, verify files arrive via `$_FILES`
 
 ### 3. Autosave text fields on partage form

app/public/assets/js/app/file-upload-filepond.js

@@ -615,11 +615,24 @@
 		console.log('[filepond] htmx detected, registering swap listeners');
 		window.htmx.on("htmx:beforeSwap", onHtmxBeforeSwap);
 		window.htmx.on("htmx:afterSwap", () => {
+			enableFilepondMode();
 			_xamxamFilepondReady = false;
 			window.XamxamInitFilePonds();
 			setTimeout(() => { _xamxamFilepondReady = true; }, 0);
 		});
 	}
+	// ── Enable filepond_mode hidden input (no-JS safety) ────────────────
+	// The hidden input starts as disabled / value=0 so the server falls
+	// back to $_FILES when JS is unavailable.  Enable it now that FilePond
+	// will handle uploads asynchronously.
+	function enableFilepondMode() {
+		var inputs = document.querySelectorAll("input[name='filepond_mode']");
+		for (var i = 0; i < inputs.length; i++) {
+			inputs[i].disabled = false;
+			inputs[i].value = "1";
+		}
+	}
+
 	// Flag set after FilePond instances are fully initialised.
 	// Before this flag is set, FilePond:addfile events are from initial load
 	// (e.g. existing files loaded in edit mode) and should not mark the form dirty.
@@ -629,10 +642,12 @@
 
 	if (document.readyState === "loading") {
 		document.addEventListener("DOMContentLoaded", () => {
+			enableFilepondMode();
 			window.XamxamInitFilePonds();
 			_xamxamFilepondReady = true;
 		});
 	} else {
+		enableFilepondMode();
 		window.XamxamInitFilePonds();
 		_xamxamFilepondReady = true;
 	}

app/src/Controllers/ThesisCreateController.php

@@ -198,7 +198,13 @@ class ThesisCreateController
         $folderPath = $objet . '/' . $data['annee'] . '/' . $folderName . '/';
         $filePrefix = $folderName;
 
-        if (!empty($post['filepond_mode'])) {
+        // Determine upload path: FilePond async (JS enabled, hex IDs present)
+        // vs. legacy multipart (no JS, or JS failed).  The hidden filepond_mode
+        // input starts disabled (value=0, not submitted); JS enables it on load.
+        // Defense-in-depth: if filepond_mode=1 but no hex IDs, fall back to $_FILES.
+        $useFilePond = !empty($post['filepond_mode']) && $this->hasFilePondQueueData($post);
+
+        if ($useFilePond) {
             // New path: files already on server via async FilePond uploads
             // Cover and note_intention also go through FilePond async flow
             $this->handleFilePondSingleFile($thesisId, $post, 'cover', $folderPath, $filePrefix);

app/src/Controllers/ThesisEditController.php

@@ -359,8 +359,12 @@ class ThesisEditController
             mkdir($dirAbs, 0755, true);
         }
 
+        // Determine upload path: FilePond async (JS enabled, hex IDs present)
+        // vs. legacy multipart. Defense-in-depth fallback for no-JS scenarios.
+        $useFilePond = !empty($post['filepond_mode']) && $this->hasFilePondQueueData($post);
+
         // ── Cover image (outside transaction — filesystem op) ─────────────────
-        if (!empty($post['filepond_mode'])) {
+        if ($useFilePond) {
             // Delete old cover only if a genuinely new cover was uploaded (hex file_id).
             // Existing cover preserved in FilePond sends its DB integer ID — skip.
             $coverIdRaw = ($post['queue_file']['cover'] ?? null);
@@ -387,7 +391,7 @@ class ThesisEditController
         }
 
         // ── Note d'intention (replace if uploaded) ────────────────────────────
-        if (!empty($post['filepond_mode'])) {
+        if ($useFilePond) {
             // Only delete + replace if a genuinely new file was uploaded (hex file_id).
             // Existing files preserved in the FilePond pool send their DB integer ID;
             // we must NOT delete them — they're already stored.
@@ -454,7 +458,7 @@ class ThesisEditController
             }
         }
 
-        if (!empty($post['filepond_mode'])) {
+        if ($useFilePond) {
             // New path: files already on server via async FilePond uploads
             $nextNum = $tfeCount + 1;
             $nextNum = $this->handleFilePondQueueFiles($thesisId, $post, 'tfe', $folderPath, $filePrefix, $nextNum);

app/src/Controllers/ThesisFileHandler.php

@@ -853,6 +853,33 @@ trait ThesisFileHandler
 
     // ── FilePond async file processing ──────────────────────────────────────
 
+    /**
+     * Check whether the POST data contains actual FilePond hex IDs (32-char hex)
+     * rather than standard file upload data.
+     *
+     * Without JS the hidden filepond_mode input is disabled and not submitted;
+     * this is a defense-in-depth fallback: if filepond_mode=1 somehow arrives but
+     * no async upload IDs are present, we treat it as a legacy $_FILES submission.
+     */
+    private function hasFilePondQueueData(array $post): bool
+    {
+        $queueKeys = ['cover', 'note_intention', 'tfe', 'annexe'];
+        foreach ($queueKeys as $key) {
+            $raw = $post['queue_file'][$key] ?? null;
+            if ($raw === null || $raw === '') {
+                continue;
+            }
+            $ids = is_array($raw) ? $raw : [$raw];
+            foreach ($ids as $id) {
+                $id = is_string($id) ? trim($id) : '';
+                if ($id !== '' && preg_match('/^[a-f0-9]{32}$/', $id)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     /**
      * Process a single file from the FilePond async flow (cover, note_intention).
      *

app/templates/partials/form/form.php

@@ -147,7 +147,9 @@ $errorFieldName = $errorFieldName ?? null;
 <?php endif; ?>
 
     <form action="<?= $formAction ?>" method="post" enctype="multipart/form-data" class="admin-form" data-beforeunload-guard>
-        <input type="hidden" name="filepond_mode" value="1">
+        <!-- Default: JS-disabled mode (disabled → not submitted → server uses $_FILES path).
+             On DOMContentLoaded, JS enables this input and sets value="1" → server uses FilePond path. -->
+        <input type="hidden" name="filepond_mode" value="0" disabled>
         <?= $hiddenFields ?>
 
         <?php if (!$adminMode): ?>