onStop of flow

What is carried out when a run is stopped, as its last work, so that it can take back what was half done.

Value

A function that is handed what run is handed, and stopped: { step, progress }, the step that was at work when the run was stopped - the one that began last and had not ended - and what that step kept with progress. Left out, a stop ends the run at once.

It is carried out once, whether the run was stopped by runs.stop, tent runs stop, runs.stopAll or stopOn, and its steps are saved like any, under their names with onStop. in front, so a restart in its middle goes on from its last saved step. It has the flow's limits.time of its own, counted anew. The run stays running while it works, and is stopped in the write that ends it, whatever it ends with; a caller that waits for the run is answered code.T5106 then. A second stop ends it at once.

Example

export const trip = flow('trip', {
  input: { name: text() },
  run: async ({ input, step }) => {
    await step('seat', () => bookSeat({ name: input.name }))
    await step('room', async ({ progress }) => {
      await progress({ booked: 'half' })
      return bookRoom({ name: input.name })
    })
  },
  onStop: async ({ input, stopped, step }) => {
    if (stopped.step === 'room') await step('undo', () => cancelRoom({ name: input.name }))
  },
})

See also

option.flow.onFail, option.flow.stopOn, word.flow, topic.flows