diff --git a/doc.go b/doc.go index 0bce85869b5..3095f42b1e5 100644 --- a/doc.go +++ b/doc.go @@ -84,4 +84,51 @@ // fmt.Println("Domain: %s", aErr.Domain()) // } // } +// +// # Polling Operations +// +// If an API call returns an Operation, that means it could take some time to +// complete the work initiated by the API call. Applications that are interested +// in the end result of the operation they initiated should wait until the +// Operation.Done field indicates it is finished. To do this, use the service's +// Operation client, and a loop, like so: +// +// import ( +// gax "github.com/googleapis/gax-go/v2" +// ) +// +// // existing application code... +// +// // API call that returns an Operation. +// op, err := myApiClient.CalculateFoo().Do() +// if err != nil { +// // handle err +// } +// +// operationsService = myapi.NewOperationsService(myApiClient) +// pollingBackoff := gax.Backoff{ +// Initial: time.Second, +// Max: time.Minute, // Max time between polling attempts. +// Multiplier: 2, +// } +// for { +// if op.Done { +// break +// } +// // not done, sleep with backoff, then poll again +// if err := gax.Sleep(ctx, pollingBackoff.Pause()); err != nil { +// // handle error +// } +// op, err := operationsService.Get(op.Name).Do() +// if err != nil { +// // handle error +// } +// } +// +// if op.Error != nil { +// // handle operation err +// } +// +// // Do something with the response +// fmt.Println(op.Response) package api