Sync updates¶

Use this procedure to keep a local copy of a document type up to date.

Procedure¶

1. Do a full read. Save each document and the latest last_modified value. With the default sort, this is the value of the first document.
2. At a later time, read with modified_after set to the saved value.
3. Save the new and changed documents. Replace documents that have the same guid.
4. Save the new latest last_modified value.
5. Do steps 2 to 4 again.

from faa_drs import DRSClient, DocType


def sync(drs: DRSClient, store, checkpoint=None):
    latest = checkpoint
    for doc in drs.iter_documents(DocType.SAIB, modified_after=checkpoint):
        store.upsert(doc.guid, doc.model_dump_json())
        if doc.last_modified and (latest is None or doc.last_modified > latest):
            latest = doc.last_modified
    return latest

Rules¶

• modified_after returns documents that changed after the time. It does not include the time.
• modified_after does not return documents that have no last_modified value. A full read gets these documents.
• If a read stops, continue from the last completed page offset. See Resume a read. Do not continue from the last last_modified value: modified_after does not include that time, so you can skip documents that have the same value.
• Keep the default sort, "DESC". If DRS updates during a long read, a later read with modified_after gets the documents that the first read missed. With "ASC", a read can skip documents that did not change, and modified_after does not find them. See Sort order.
• DRS updates every 24 hours. Do not sync more frequently than this.