def on_snapshot(self, callback):
"""Watch this document.
This starts a watch on this document using a background thread. The
provided callback is run on the snapshot.
Args:
callback(~.firestore.document.DocumentSnapshot):a callback to run
when a change occurs
Example:
from google.cloud import firestore_v1beta1
db = firestore_v1beta1.Client()
collection_ref = db.collection(u'users')
def on_snapshot(document_snapshot):
doc = document_snapshot
print(u'{} => {}'.format(doc.id, doc.to_dict()))
doc_ref = db.collection(u'users').document(
u'alovelace' + unique_resource_id())
# Watch this document
doc_watch = doc_ref.on_snapshot(on_snapshot)
# Terminate this watch
doc_watch.unsubscribe()
"""
return Watch.for_document(self, callback, DocumentSnapshot, DocumentReference)
def test_for_document(self):
from google.cloud.firestore_v1beta1.watch import Watch
docref = DummyDocumentReference()
snapshot_callback = self._snapshot_callback
snapshot_class_instance = DummyDocumentSnapshot
document_reference_class_instance = DummyDocumentReference
modulename = "google.cloud.firestore_v1beta1.watch"
with mock.patch("%s.Watch.ResumableBidiRpc" % modulename, DummyRpc):
with mock.patch("%s.Watch.BackgroundConsumer" % modulename,
DummyBackgroundConsumer):
inst = Watch.for_document(
docref,
snapshot_callback,
snapshot_class_instance,
document_reference_class_instance,
)
self.assertTrue(inst._consumer.started)
self.assertTrue(inst._rpc.callbacks, [inst._on_rpc_done])
def test_for_document(self):
from google.cloud.firestore_v1beta1.watch import Watch
docref = DummyDocumentReference()
snapshot_callback = self._snapshot_callback
snapshot_class_instance = DummyDocumentSnapshot
document_reference_class_instance = DummyDocumentReference
modulename = "google.cloud.firestore_v1beta1.watch"
with mock.patch("%s.Watch.ResumableBidiRpc" % modulename, DummyRpc):
with mock.patch(
"%s.Watch.BackgroundConsumer" % modulename, DummyBackgroundConsumer
):
inst = Watch.for_document(
docref,
snapshot_callback,
snapshot_class_instance,
document_reference_class_instance,
)
self.assertTrue(inst._consumer.started)
self.assertTrue(inst._rpc.callbacks, [inst._on_rpc_done])