pathSegmentPop static method

bool pathSegmentPop(BuildContext context, BeamerDelegate delegate, RouteInformationSerializable state, BeamPage poppedPage,)

The default pop behavior for BeamPage.

Pops the last path segment from URI and calls BeamerDelegate.update.

Implementation

static bool pathSegmentPop(
  BuildContext context,
  BeamerDelegate delegate,
  RouteInformationSerializable state,
  BeamPage poppedPage,
) {
  if (!delegate.navigator.canPop()) {
    return false;
  }

  // take the data in case we remove the BeamLocation from history
  // and generate a new one (but the same).
  final data = delegate.currentBeamLocation.data;

  // Take the history element that is being popped and the one before
  // as they will be compared later on to fine-tune the pop experience.
  final poppedHistoryElement = delegate.removeLastHistoryElement()!;
  final previousHistoryElement = delegate.beamingHistory.isNotEmpty
      ? delegate.beamingHistory.last.history.last
      : null;

  // Convert both to Uri as their path and query will be compared.
  final poppedUri = poppedHistoryElement.routeInformation.uri;
  final previousUri = previousHistoryElement != null
      ? previousHistoryElement.routeInformation.uri
      : Uri.parse(delegate.initialPath);

  final poppedPathSegments = poppedUri.pathSegments;
  final poppedQueryParameters = poppedUri.queryParameters;

  // Pop path is obtained via removing the last path segment from path
  // that is being popped.
  final popPathSegments = List.from(poppedPathSegments)..removeLast();
  final popPath = '/' + popPathSegments.join('/');
  final popUri = Uri(
    path: popPath,
    queryParameters: poppedPage.keepQueryOnPop
        ? poppedQueryParameters.isEmpty
            ? null
            : poppedQueryParameters
        : (popPath == previousUri.path)
            ? previousUri.queryParameters.isEmpty
                ? null
                : previousUri.queryParameters
            : null,
  );

  // We need the route information from the route we are trying to pop to.
  //
  // Remove the last history element if it's the same as the path
  // we're trying to pop to, because `update` will add it to history.
  // This is `false` in case we deep-linked.
  //
  // Otherwise, find the route information with popPath in history.
  RouteInformation? lastRouteInformation;
  if (popPath == previousUri.path) {
    lastRouteInformation =
        delegate.removeLastHistoryElement()?.routeInformation;
  } else {
    // find the last
    var found = false;
    for (var beamLocation in delegate.beamingHistory.reversed) {
      if (found) {
        break;
      }
      for (var historyElement in beamLocation.history.reversed) {
        final uri = historyElement.routeInformation.uri;
        if (uri.path == popPath) {
          lastRouteInformation = historyElement.routeInformation;
          found = true;
          break;
        }
      }
    }
  }

  delegate.update(
    configuration: delegate.configuration.copyWith(
      uri: popUri,
      state: lastRouteInformation?.state,
    ),
    data: data,
  );

  return true;
}