Working with APIs that make take a long time to complete
Some scenarios, like copy or upload from URL cannot always be completed in a finite amount of time. To handle these scenarios and keep API response latency low, these actions are implemented using a long running actions pattern.
- App requests a long running action via the API. The API accepts the action and returns a
202 Acceptedresponse along with a Location header for the API URL to retrieve action status reports. - App requests the action status report URL and receives an AsyncJobStatus response with the progress of the long running action
- The long running action completes. Next time the app requests the action status report URL and receives an AsyncJobStatus response with the completion of the action.
Initial action request
Let's walk through the steps for an example copy scenario. In this scenario, an app requests to copy a folder with a large amount of data contained within. This request will likely take several seconds to complete since the amount of data is large.
POST /drive/items/{folder-item-id}/copy
Content-Type: application/json
Prefer: respond-async
{
"parentReference": {
"path": "/drive/root:/Documents"
},
"name": "Copy of LargeFolder1"
}
The API responds that the action was accepted and the URL for retrieving the status of the long running action.
HTTP/1.1 202 Accepted
Location: https://api.onedrive.com/monitor/4A3407B5-88FC-4504-8B21-0AABD3412717
In many cases this many be the end of the request, since the copy action will complete without the app doing any additional work. However, if the app wants to show the status of the copy action or ensure that it completes without error, it can do so using the monitor URL.
Retrieve a status report from the monitor URL
To check on the status of the copy action, the app makes a request to the URL provided in the previous response. Note: This request does not require authentication, since the URL is short-lived and unique to the original caller.
GET https://api.onedrive.com/monitor/4A3407B5-88FC-4504-8B21-0AABD3412717
The service responses with information that the long running action is still in progress:
HTTP/1.1 202 Accepted
Content-type: application/json
{
"operation": "ItemCopy",
"percentageComplete": 27.8,
"status": "inProgress"
}
This information can be used to provide an update to the user about the progress of the copy action. The app can continue to poll the monitor URL to request status updates and keep track of the progress of the action.
Retrieve a completed status report from the monitor URL
After a few seconds the copy operation has completed. This time when the app makes a request to the monitor URL the response is a redirection to the finished result of the action.
GET https://api.onedrive.com/monitor/4A3407B5-88FC-4504-8B21-0AABD3412717
When the action has completed, the response from the monitor service will return the resourceId for the results.
HTTP/1.1 303 See Other
Content-type: application/json
{
"percentageComplete": 100.0,
"resourceId": "01MOWKYVJML57KN2ANMBA3JZJS2MBGC7KM",
"status": "completed"
}