getFlowStepTrigger method

int? getFlowStepTrigger(
  1. String? previousDocumentKey
)

Parse a previousDocumentKey of the form "step:N" and return N or null.

Implementation

int? getFlowStepTrigger(String? previousDocumentKey) {
  if (previousDocumentKey == null) {
    return null;
  }
  final prefix = '__step__:';
  if (previousDocumentKey.startsWith(prefix)) {
    final rest = previousDocumentKey.substring(prefix.length);
    final n = int.tryParse(rest);
    return n;
  }
  return null;
}