Add delete functionality for draft declarations

Delete Feature:
- Added deleteDeclaration() method to DeclarationTVA class
- Only allows deletion of draft declarations (safety check)
- Deletes CA-3 lines first, then declaration record
- Added delete button to main interface for draft declarations
- Added confirmation dialog before deletion
- Added success/error messages for delete operations
- Added translations in both English and French

Security:
- Only draft declarations can be deleted
- Confirmation dialog prevents accidental deletion
- Proper error handling and user feedback

The interface now shows a delete button for each draft declaration!

core/class/declarationtva.class.php

@@ -456,4 +456,43 @@ class DeclarationTVA
         $result = $this->db->query($sql);
         return $result !== false;
     }
+
+    /**
+     * Delete a declaration
+     *
+     * @param int $declaration_id Declaration ID
+     * @return bool Success
+     */
+    public function deleteDeclaration($declaration_id)
+    {
+        $this->db->begin();
+
+        // Check if declaration exists and is in draft status
+        $sql = "SELECT status FROM " . MAIN_DB_PREFIX . "declarationtva_declarations 
+                WHERE rowid = " . (int)$declaration_id . " AND entity = " . $this->entity;
+        
+        $result = $this->db->query($sql);
+        if ($result) {
+            $obj = $this->db->fetch_object($result);
+            if ($obj && $obj->status == 'draft') {
+                // Delete CA-3 lines first
+                $sql_lines = "DELETE FROM " . MAIN_DB_PREFIX . "declarationtva_ca3_lines 
+                              WHERE declaration_id = " . (int)$declaration_id;
+                $this->db->query($sql_lines);
+
+                // Delete declaration
+                $sql_declaration = "DELETE FROM " . MAIN_DB_PREFIX . "declarationtva_declarations 
+                                   WHERE rowid = " . (int)$declaration_id . " AND entity = " . $this->entity;
+                
+                $result = $this->db->query($sql_declaration);
+                if ($result) {
+                    $this->db->commit();
+                    return true;
+                }
+            }
+        }
+
+        $this->db->rollback();
+        return false;
+    }
 }

declarationtvaindex.php

@@ -61,6 +61,12 @@ if ($action == 'create_declaration' && $period_id > 0) {
     } else {
         setEventMessages($langs->trans("ErrorSubmittingDeclaration"), null, 'errors');
     }
+} elseif ($action == 'delete_declaration' && $declaration_id > 0) {
+    if ($declarationtva->deleteDeclaration($declaration_id)) {
+        setEventMessages($langs->trans("DeclarationDeleted"), null, 'mesgs');
+    } else {
+        setEventMessages($langs->trans("ErrorDeletingDeclaration"), null, 'errors');
+    }
 }
 
 // Get data for display
@@ -129,6 +135,7 @@ if (empty($declarations)) {
         
         if ($d['status'] == 'draft') {
             print '<a href="' . $_SERVER['PHP_SELF'] . '?action=validate_declaration&declaration_id=' . $d['rowid'] . '" class="butAction">' . $langs->trans("Validate") . '</a>';
+            print '<a href="' . $_SERVER['PHP_SELF'] . '?action=delete_declaration&declaration_id=' . $d['rowid'] . '" class="butActionDelete" onclick="return confirm(\'' . $langs->trans("ConfirmDeleteDeclaration") . '\')">' . $langs->trans("Delete") . '</a>';
         } elseif ($d['status'] == 'validated') {
             print '<a href="' . $_SERVER['PHP_SELF'] . '?action=submit_declaration&declaration_id=' . $d['rowid'] . '" class="butAction">' . $langs->trans("Submit") . '</a>';
         }

langs/en_US/declarationtva.lang

@@ -402,7 +402,11 @@ DeclarationSubmitted = Declaration submitted successfully
 ErrorCreatingDeclaration = Error creating declaration
 ErrorValidatingDeclaration = Error validating declaration
 ErrorSubmittingDeclaration = Error submitting declaration
+ErrorDeletingDeclaration = Error deleting declaration
 ErrorMissingDates = Please provide both start and end dates
+DeclarationDeleted = Declaration deleted successfully
+Delete = Delete
+ConfirmDeleteDeclaration = Are you sure you want to delete this declaration? This action cannot be undone.
 
 # Create Declaration Page
 DeclarationDetails = Declaration Details

langs/fr_FR/declarationtva.lang

@@ -391,7 +391,11 @@ DeclarationSubmitted = Déclaration soumise avec succès
 ErrorCreatingDeclaration = Erreur lors de la création de la déclaration
 ErrorValidatingDeclaration = Erreur lors de la validation de la déclaration
 ErrorSubmittingDeclaration = Erreur lors de la soumission de la déclaration
+ErrorDeletingDeclaration = Erreur lors de la suppression de la déclaration
 ErrorMissingDates = Veuillez fournir les dates de début et de fin
+DeclarationDeleted = Déclaration supprimée avec succès
+Delete = Supprimer
+ConfirmDeleteDeclaration = Êtes-vous sûr de vouloir supprimer cette déclaration ? Cette action ne peut pas être annulée.
 
 # Create Declaration Page
 DeclarationDetails = Détails de la déclaration