Method widgetAdd

app/src/API/Handlers/WorkspacesHandler.cpp:1069–1161

* @brief Attaches a widget ref to a workspace. */

 * @brief Attaches a widget ref to a workspace.
 */
API::CommandResponse API::Handlers::WorkspacesHandler::widgetAdd(const QString& id,
                                                                 const QJsonObject& params)
{
  if (!inProjectFileMode())
    return CommandResponse::makeError(
      id, ErrorCode::InvalidParam, QStringLiteral("Workspace mutations require ProjectFile mode"));

  const QStringList required{
    QStringLiteral("workspaceId"),
    QStringLiteral("widgetType"),
    QStringLiteral("groupId"),
  };

  for (const auto& key : required)
    if (!params.contains(key))
      return CommandResponse::makeError(
        id, ErrorCode::MissingParam, QStringLiteral("Missing required parameter: %1").arg(key));

  auto& pm = DataModel::ProjectModel::instance();
  if (!pm.customizeWorkspaces())
    return CommandResponse::makeError(
      id,
      ErrorCode::InvalidParam,
      QStringLiteral("customizeWorkspaces is off; call project.workspaces.customize.set first"));

  const int wid = params.value(QStringLiteral("workspaceId")).toInt();
  const int gid = params.value(QStringLiteral("groupId")).toInt();

  const QJsonValue wtypeJson = params.value(QStringLiteral("widgetType"));
  const int wtype            = resolveWidgetType(wtypeJson);
  if (const auto err = validateResolvedWidgetType(wtype, wtypeJson))
    return CommandResponse::makeError(id, ErrorCode::InvalidParam, *err);

  const auto& wsList = pm.editorWorkspaces();
  const auto exists  = std::any_of(
    wsList.begin(), wsList.end(), [wid](const auto& ws) { return ws.workspaceId == wid; });
  if (!exists)
    return CommandResponse::makeError(
      id, ErrorCode::InvalidParam, QStringLiteral("Workspace not found: %1").arg(wid));

  const auto& groups  = DataModel::ProjectModel::instance().groups();
  const auto group_it = std::find_if(
    groups.begin(), groups.end(), [gid](const DataModel::Group& g) { return g.uniqueId == gid; });
  if (group_it == groups.end())
    return CommandResponse::makeError(id,
                                      ErrorCode::InvalidParam,
                                      QStringLiteral("Group not found: %1. Use uniqueId from "
                                                     "project.group.list, not the array index.")
                                        .arg(gid));

  if (const auto err = validateGroupCompatibility(*group_it, wtype, gid))
    return CommandResponse::makeError(id, ErrorCode::InvalidParam, *err);

  const bool hasRelIndex    = params.contains(QStringLiteral("relativeIndex"));
  const bool hasDatasetId   = params.contains(Keys::DatasetId);
  const int targetDatasetId = hasDatasetId ? params.value(Keys::DatasetId).toInt() : -1;

  if (hasDatasetId)