The handleFlowRequest(ExternalContext) method is the central helper operation and implements the following algorithm:

1. Extract the flow execution id by calling extractFlowExecutionKey(ExternalContext) .
2. If a valid flow execution id was extracted, signal an event in that existing execution to resume it. The event to signal is determined by calling the extractEventId(ExternalContext) method.
3. If no flow execution id was extracted, launch a new flow execution. The top-level flow definition for which an execution is created is determined by extracting the flow id using the extractFlowId(ExternalContext) . If this parameter is not present, an exception is thrown.