Documents

Classes for representing documents for the Google Cloud Firestore API.

class google.cloud.firestore_v1.document.DocumentReference(*path, **kwargs)

Bases: google.cloud.firestore_v1.base_document.BaseDocumentReference

A reference to a document in a Firestore database.

The document may already exist or can be created by this class.

Parameters
- path (Tuple[str, **...]) – The components in the document path. This is a series of strings representing each collection and sub-collection ID, as well as the document IDs for any documents that contain a sub-collection (as well as the base document).
- kwargs (dict) – The keyword arguments for the constructor. The only supported keyword is client and it must be a Client. It represents the client that created this document reference.
Raises
- ValueError – if
  
  * the path is empty * there are an even number of elements * a collection ID in path is not a string * a document ID in path is not a string
- TypeError – If a keyword other than client is used.

collections(page_size: Optional[int] = None, retry: google.api_core.retry.Retry = <_MethodDefault._DEFAULT_VALUE:

List subcollections of the current document.

Parameters
- page_size (Optional[int]]) – The maximum number of collections in each page of results from this request. Non-positive values are ignored. Defaults to a sensible value set by the API.
- retry (google.api_core.retry.Retry) – Designation of what errors, if any, should be retried. Defaults to a system-specified policy.
- timeout (float) – The timeout for this request. Defaults to a system-specified value.
Returns

iterator of subcollections of the current document. If the document does not exist at the time of snapshot, the iterator will be empty
Return type

Sequence[CollectionReference]

create(document_data: dict, retry: google.api_core.retry.Retry = <_MethodDefault._DEFAULT_VALUE:

Create the current document in the Firestore database.

Parameters
- document_data (dict) – Property names and values to use for creating a document.
- retry (google.api_core.retry.Retry) – Designation of what errors, if any, should be retried. Defaults to a system-specified policy.
- timeout (float) – The timeout for this request. Defaults to a system-specified value.
Returns

The write result corresponding to the committed document. A write result contains an update_time field.
Return type

WriteResult
Raises

Conflict – If the document already exists.

delete(option: Optional[google.cloud.firestore_v1._helpers.WriteOption] = None, retry: google.api_core.retry.Retry = <_MethodDefault._DEFAULT_VALUE:

Delete the current document in the Firestore database.

Parameters
- option (Optional[WriteOption]) – A write option to make assertions / preconditions on the server state of the document before applying changes.
- retry (google.api_core.retry.Retry) – Designation of what errors, if any, should be retried. Defaults to a system-specified policy.
- timeout (float) – The timeout for this request. Defaults to a system-specified value.
Returns

The time that the delete request was received by the server. If the document did not exist when the delete was sent (i.e. nothing was deleted), this method will still succeed and will still return the time that the request was received by the server.
Return type

google.protobuf.timestamp_pb2.Timestamp

get(field_paths: Optional[Iterable[str]] = None, transaction=None, retry: google.api_core.retry.Retry = <_MethodDefault._DEFAULT_VALUE:

Retrieve a snapshot of the current document.

See field_path() for more information on field paths.

If a transaction is used and it already has write operations added, this method cannot be used (i.e. read-after-write is not allowed).

Parameters
- field_paths (Optional[Iterable[str, **...]]) – An iterable of field paths (.-delimited list of field names) to use as a projection of document fields in the returned results. If no value is provided, all fields will be returned.
- transaction (Optional[Transaction]) – An existing transaction that this reference will be retrieved in.
- retry (google.api_core.retry.Retry) – Designation of what errors, if an y, should be retried. Defaults to a system-specified policy.
- timeout (float) – The timeout for this request. Defaults to a system-specified value.
Returns

A snapshot of the current document. If the document does not exist at the time of the snapshot is taken, the snapshot’s reference, data, update_time, and create_time attributes will all be None and its exists attribute will be False.
Return type

DocumentSnapshot

on_snapshot(callback: Callable)

Watch this document.

This starts a watch on this document using a background thread. The provided callback is run on the snapshot.

Parameters

callback (Callable[[DocumentSnapshot], NoneType]) – a callback to run when a change occurs

Example:

from google.cloud import firestore_v1

db = firestore_v1.Client()
collection_ref = db.collection(u'users')

def on_snapshot(document_snapshot, changes, read_time):
    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()

set(document_data: dict, merge: bool = False, retry: google.api_core.retry.Retry = <_MethodDefault._DEFAULT_VALUE:

Replace the current document in the Firestore database.

A write option can be specified to indicate preconditions of the “set” operation. If no option is specified and this document doesn’t exist yet, this method will create it.

Overwrites all content for the document with the fields in document_data. This method performs almost the same functionality as create(). The only difference is that this method doesn’t make any requirements on the existence of the document (unless option is used), whereas as create() will fail if the document already exists.

Parameters
- document_data (dict) – Property names and values to use for replacing a document.
- merge (Optional[bool] or **Optional[List]) – If True, apply merging instead of overwriting the state of the document.
- retry (google.api_core.retry.Retry) – Designation of what errors, if any, should be retried. Defaults to a system-specified policy.
- timeout (float) – The timeout for this request. Defaults to a system-specified value.
Returns

The write result corresponding to the committed document. A write result contains an update_time field.
Return type

WriteResult

update(field_updates: dict, option: Optional[google.cloud.firestore_v1._helpers.WriteOption] = None, retry: google.api_core.retry.Retry = <_MethodDefault._DEFAULT_VALUE:

Update an existing document in the Firestore database.

By default, this method verifies that the document exists on the server before making updates. A write option can be specified to override these preconditions.

Each key in field_updates can either be a field name or a field path (For more information on field paths, see field_path().) To illustrate this, consider a document with

>>> snapshot = document.get()
>>> snapshot.to_dict()
{
    'foo': {
        'bar': 'baz',
    },
    'other': True,
}

stored on the server. If the field name is used in the update:

>>> field_updates = {
...     'foo': {
...         'quux': 800,
...     },
... }
>>> document.update(field_updates)

then all of foo will be overwritten on the server and the new value will be

>>> snapshot = document.get()
>>> snapshot.to_dict()
{
    'foo': {
        'quux': 800,
    },
    'other': True,
}

On the other hand, if a .-delimited field path is used in the update:

>>> field_updates = {
...     'foo.quux': 800,
... }
>>> document.update(field_updates)

then only foo.quux will be updated on the server and the field foo.bar will remain intact:

>>> snapshot = document.get()
>>> snapshot.to_dict()
{
    'foo': {
        'bar': 'baz',
        'quux': 800,
    },
    'other': True,
}

WARNING: A field path can only be used as a top-level key in field_updates.

To delete / remove a field from an existing document, use the DELETE_FIELD sentinel. So with the example above, sending

>>> field_updates = {
...     'other': firestore.DELETE_FIELD,
... }
>>> document.update(field_updates)

would update the value on the server to:

>>> snapshot = document.get()
>>> snapshot.to_dict()
{
    'foo': {
        'bar': 'baz',
    },
}

To set a field to the current time on the server when the update is received, use the SERVER_TIMESTAMP sentinel. Sending

>>> field_updates = {
...     'foo.now': firestore.SERVER_TIMESTAMP,
... }
>>> document.update(field_updates)

would update the value on the server to:

>>> snapshot = document.get()
>>> snapshot.to_dict()
{
    'foo': {
        'bar': 'baz',
        'now': datetime.datetime(2012, ...),
    },
    'other': True,
}

Parameters
- field_updates (dict) – Field names or paths to update and values to update with.
- option (Optional[WriteOption]) – A write option to make assertions / preconditions on the server state of the document before applying changes.
- retry (google.api_core.retry.Retry) – Designation of what errors, if any, should be retried. Defaults to a system-specified policy.
- timeout (float) – The timeout for this request. Defaults to a system-specified value.
Returns

The write result corresponding to the updated document. A write result contains an update_time field.
Return type

WriteResult
Raises

NotFound – If the document does not exist.