Add SHACL form patch to preserve multi-value blank nodes

Author: ErykKul

previewers/betatest/CdiPreview.html

@@ -6,6 +6,7 @@
     <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
     <script type="text/javascript" src="js/xss.js"></script>
     <script type="module" src="js/shacl-form.js"></script>
+    <script type="text/javascript" src="js/shacl-form-patch.js"></script>
     <script src="lib/jquery.i18n.js"></script>
     <script src="lib/jquery.i18n.messagestore.js"></script>
     <script src="lib/jquery.i18n.language.js"></script>

previewers/betatest/js/shacl-form-patch.js

@@ -0,0 +1,54 @@
+/**
+ * Guard the shacl-form implementation so that multi-value blank nodes remain visible even when
+ * nested nodes currently violate their shape (e.g., missing required fields). Without this guard
+ * the component drops every value after validation and users cannot fix the data.
+ * 
+ * This patch must be loaded AFTER the shacl-form web component is imported.
+ */
+
+(function() {
+    'use strict';
+    
+    // Wait for custom elements to be defined
+    async function applyPatch() {
+        // Wait for shacl-property element to be defined
+        await customElements.whenDefined('shacl-property');
+        
+        const shaclPropertyCtor = customElements.get('shacl-property');
+        
+        if (shaclPropertyCtor && !shaclPropertyCtor.__rdmFilterGuardApplied) {
+            const prototype = shaclPropertyCtor.prototype;
+            const originalFilter = prototype.filterValidValues;
+            
+            if (typeof originalFilter === 'function') {
+                console.log('[SHACL Patch] Applying filterValidValues guard for multi-value blank nodes');
+                
+                prototype.filterValidValues = async function(values, subject) {
+                    // If there's no qualifiedValueShape, don't filter - keep all values
+                    if (!this?.template?.qualifiedValueShape) {
+                        return values;
+                    }
+                    
+                    // Otherwise, use the original validation logic
+                    return originalFilter.call(this, values, subject);
+                };
+                
+                shaclPropertyCtor.__rdmFilterGuardApplied = true;
+                console.log('[SHACL Patch] Guard applied successfully');
+            } else {
+                console.warn('[SHACL Patch] filterValidValues method not found');
+            }
+        } else if (shaclPropertyCtor?.__rdmFilterGuardApplied) {
+            console.log('[SHACL Patch] Guard already applied');
+        } else {
+            console.error('[SHACL Patch] shacl-property element not found');
+        }
+    }
+    
+    // Apply patch when DOM is ready
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', applyPatch);
+    } else {
+        applyPatch();
+    }
+})();