# Copyright 2017 Google LLC All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """Classes for representing documents for the Google Cloud Firestore API.""" import copy import six from google.api_core import exceptions from google.cloud.firestore_v1beta1 import _helpers from google.cloud.firestore_v1beta1 import field_path as field_path_module from google.cloud.firestore_v1beta1.proto import common_pb2 from google.cloud.firestore_v1beta1.watch import Watch class DocumentReference(object): """A reference to a document in a Firestore database. The document may already exist or can be created by this class. Args: 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 :class:`~google.cloud.firestore_v1beta1.client.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. """ _document_path_internal = None def __init__(self, *path, **kwargs): _helpers.verify_path(path, is_collection=False) self._path = path self._client = kwargs.pop("client", None) if kwargs: raise TypeError( "Received unexpected arguments", kwargs, "Only `client` is supported" ) def __copy__(self): """Shallow copy the instance. We leave the client "as-is" but tuple-unpack the path. Returns: .DocumentReference: A copy of the current document. """ result = self.__class__(*self._path, client=self._client) result._document_path_internal = self._document_path_internal return result def __deepcopy__(self, unused_memo): """Deep copy the instance. This isn't a true deep copy, wee leave the client "as-is" but tuple-unpack the path. Returns: .DocumentReference: A copy of the current document. """ return self.__copy__() def __eq__(self, other): """Equality check against another instance. Args: other (Any): A value to compare against. Returns: Union[bool, NotImplementedType]: Indicating if the values are equal. """ if isinstance(other, DocumentReference): return self._client == other._client and self._path == other._path else: return NotImplemented def __hash__(self): return hash(self._path) + hash(self._client) def __ne__(self, other): """Inequality check against another instance. Args: other (Any): A value to compare against. Returns: Union[bool, NotImplementedType]: Indicating if the values are not equal. """ if isinstance(other, DocumentReference): return self._client != other._client or self._path != other._path else: return NotImplemented @property def path(self): """Database-relative for this document. Returns: str: The document's relative path. """ return "/".join(self._path) @property def _document_path(self): """Create and cache the full path for this document. Of the form: ``projects/{project_id}/databases/{database_id}/... documents/{document_path}`` Returns: str: The full document path. Raises: ValueError: If the current document reference has no ``client``. """ if self._document_path_internal is None: if self._client is None: raise ValueError("A document reference requires a `client`.") self._document_path_internal = _get_document_path(self._client, self._path) return self._document_path_internal @property def id(self): """The document identifier (within its collection). Returns: str: The last component of the path. """ return self._path[-1] @property def parent(self): """Collection that owns the current document. Returns: ~.firestore_v1beta1.collection.CollectionReference: The parent collection. """ parent_path = self._path[:-1] return self._client.collection(*parent_path) def collection(self, collection_id): """Create a sub-collection underneath the current document. Args: collection_id (str): The sub-collection identifier (sometimes referred to as the "kind"). Returns: ~.firestore_v1beta1.collection.CollectionReference: The child collection. """ child_path = self._path + (collection_id,) return self._client.collection(*child_path) def create(self, document_data): """Create the current document in the Firestore database. Args: document_data (dict): Property names and values to use for creating a document. Returns: google.cloud.firestore_v1beta1.types.WriteResult: The write result corresponding to the committed document. A write result contains an ``update_time`` field. Raises: ~google.cloud.exceptions.Conflict: If the document already exists. """ batch = self._client.batch() batch.create(self, document_data) write_results = batch.commit() return _first_write_result(write_results) def set(self, document_data, merge=False): """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 :meth:`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 :meth:`create` will fail if the document already exists. Args: 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. Returns: google.cloud.firestore_v1beta1.types.WriteResult: The write result corresponding to the committed document. A write result contains an ``update_time`` field. """ batch = self._client.batch() batch.set(self, document_data, merge=merge) write_results = batch.commit() return _first_write_result(write_results) def update(self, field_updates, option=None): """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 :meth:`~google.cloud.firestore_v1beta1.client.Client.field_path`.) To illustrate this, consider a document with .. code-block:: python >>> snapshot = document.get() >>> snapshot.to_dict() { 'foo': { 'bar': 'baz', }, 'other': True, } stored on the server. If the field name is used in the update: .. code-block:: python >>> 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 .. code-block:: python >>> 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: .. code-block:: python >>> 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: .. code-block:: python >>> 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 :attr:`~google.cloud.firestore_v1beta1.transforms.DELETE_FIELD` sentinel. So with the example above, sending .. code-block:: python >>> field_updates = { ... 'other': firestore.DELETE_FIELD, ... } >>> document.update(field_updates) would update the value on the server to: .. code-block:: python >>> 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 :attr:`~google.cloud.firestore_v1beta1.transforms.SERVER_TIMESTAMP` sentinel. Sending .. code-block:: python >>> field_updates = { ... 'foo.now': firestore.SERVER_TIMESTAMP, ... } >>> document.update(field_updates) would update the value on the server to: .. code-block:: python >>> snapshot = document.get() >>> snapshot.to_dict() { 'foo': { 'bar': 'baz', 'now': datetime.datetime(2012, ...), }, 'other': True, } Args: field_updates (dict): Field names or paths to update and values to update with. option (Optional[~.firestore_v1beta1.client.WriteOption]): A write option to make assertions / preconditions on the server state of the document before applying changes. Returns: google.cloud.firestore_v1beta1.types.WriteResult: The write result corresponding to the updated document. A write result contains an ``update_time`` field. Raises: ~google.cloud.exceptions.NotFound: If the document does not exist. """ batch = self._client.batch() batch.update(self, field_updates, option=option) write_results = batch.commit() return _first_write_result(write_results) def delete(self, option=None): """Delete the current document in the Firestore database. Args: option (Optional[~.firestore_v1beta1.client.WriteOption]): A write option to make assertions / preconditions on the server state of the document before applying changes. Returns: google.protobuf.timestamp_pb2.Timestamp: 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. """ write_pb = _helpers.pb_for_delete(self._document_path, option) commit_response = self._client._firestore_api.commit( self._client._database_string, [write_pb], transaction=None, metadata=self._client._rpc_metadata, ) return commit_response.commit_time def get(self, field_paths=None, transaction=None): """Retrieve a snapshot of the current document. See :meth:`~google.cloud.firestore_v1beta1.client.Client.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). Args: 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[~.firestore_v1beta1.transaction.\ Transaction]): An existing transaction that this reference will be retrieved in. Returns: ~.firestore_v1beta1.document.DocumentSnapshot: A snapshot of the current document. If the document does not exist at the time of `snapshot`, the snapshot `reference`, `data`, `update_time`, and `create_time` attributes will all be `None` and `exists` will be `False`. """ if isinstance(field_paths, six.string_types): raise ValueError("'field_paths' must be a sequence of paths, not a string.") if field_paths is not None: mask = common_pb2.DocumentMask(field_paths=sorted(field_paths)) else: mask = None firestore_api = self._client._firestore_api try: document_pb = firestore_api.get_document( self._document_path, mask=mask, transaction=_helpers.get_transaction_id(transaction), metadata=self._client._rpc_metadata, ) except exceptions.NotFound: data = None exists = False create_time = None update_time = None else: data = _helpers.decode_dict(document_pb.fields, self._client) exists = True create_time = document_pb.create_time update_time = document_pb.update_time return DocumentSnapshot( reference=self, data=data, exists=exists, read_time=None, # No server read_time available create_time=create_time, update_time=update_time, ) def collections(self, page_size=None): """List subcollections of the current document. Args: 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. Returns: Sequence[~.firestore_v1beta1.collection.CollectionReference]: iterator of subcollections of the current document. If the document does not exist at the time of `snapshot`, the iterator will be empty """ iterator = self._client._firestore_api.list_collection_ids( self._document_path, page_size=page_size, metadata=self._client._rpc_metadata, ) iterator.document = self iterator.item_to_value = _item_to_collection_ref return iterator 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) class DocumentSnapshot(object): """A snapshot of document data in a Firestore database. This represents data retrieved at a specific time and may not contain all fields stored for the document (i.e. a hand-picked selection of fields may have been retrieved). Instances of this class are not intended to be constructed by hand, rather they'll be returned as responses to various methods, such as :meth:`~google.cloud.DocumentReference.get`. Args: reference (~.firestore_v1beta1.document.DocumentReference): A document reference corresponding to the document that contains the data in this snapshot. data (Dict[str, Any]): The data retrieved in the snapshot. exists (bool): Indicates if the document existed at the time the snapshot was retrieved. read_time (google.protobuf.timestamp_pb2.Timestamp): The time that this snapshot was read from the server. create_time (google.protobuf.timestamp_pb2.Timestamp): The time that this document was created. update_time (google.protobuf.timestamp_pb2.Timestamp): The time that this document was last updated. """ def __init__(self, reference, data, exists, read_time, create_time, update_time): self._reference = reference # We want immutable data, so callers can't modify this value # out from under us. self._data = copy.deepcopy(data) self._exists = exists self.read_time = read_time """google.protobuf.timestamp_pb2.Timestamp: Time snapshot was read.""" self.create_time = create_time """google.protobuf.timestamp_pb2.Timestamp: Document's creation.""" self.update_time = update_time """google.protobuf.timestamp_pb2.Timestamp: Document's last update.""" def __eq__(self, other): if not isinstance(other, self.__class__): return NotImplemented return self._reference == other._reference and self._data == other._data def __hash__(self): seconds = self.update_time.seconds nanos = self.update_time.nanos return hash(self._reference) + hash(seconds) + hash(nanos) @property def _client(self): """The client that owns the document reference for this snapshot. Returns: ~.firestore_v1beta1.client.Client: The client that owns this document. """ return self._reference._client @property def exists(self): """Existence flag. Indicates if the document existed at the time this snapshot was retrieved. Returns: bool: The existence flag. """ return self._exists @property def id(self): """The document identifier (within its collection). Returns: str: The last component of the path of the document. """ return self._reference.id @property def reference(self): """Document reference corresponding to document that owns this data. Returns: ~.firestore_v1beta1.document.DocumentReference: A document reference corresponding to this document. """ return self._reference def get(self, field_path): """Get a value from the snapshot data. If the data is nested, for example: .. code-block:: python >>> snapshot.to_dict() { 'top1': { 'middle2': { 'bottom3': 20, 'bottom4': 22, }, 'middle5': True, }, 'top6': b'\x00\x01 foo', } a **field path** can be used to access the nested data. For example: .. code-block:: python >>> snapshot.get('top1') { 'middle2': { 'bottom3': 20, 'bottom4': 22, }, 'middle5': True, } >>> snapshot.get('top1.middle2') { 'bottom3': 20, 'bottom4': 22, } >>> snapshot.get('top1.middle2.bottom3') 20 See :meth:`~google.cloud.firestore_v1beta1.client.Client.field_path` for more information on **field paths**. A copy is returned since the data may contain mutable values, but the data stored in the snapshot must remain immutable. Args: field_path (str): A field path (``.``-delimited list of field names). Returns: Any or None: (A copy of) the value stored for the ``field_path`` or None if snapshot document does not exist. Raises: KeyError: If the ``field_path`` does not match nested data in the snapshot. """ if not self._exists: return None nested_data = field_path_module.get_nested_value(field_path, self._data) return copy.deepcopy(nested_data) def to_dict(self): """Retrieve the data contained in this snapshot. A copy is returned since the data may contain mutable values, but the data stored in the snapshot must remain immutable. Returns: Dict[str, Any] or None: The data in the snapshot. Returns None if reference does not exist. """ if not self._exists: return None return copy.deepcopy(self._data) def _get_document_path(client, path): """Convert a path tuple into a full path string. Of the form: ``projects/{project_id}/databases/{database_id}/... documents/{document_path}`` Args: client (~.firestore_v1beta1.client.Client): The client that holds configuration details and a GAPIC client object. path (Tuple[str, ...]): The components in a document path. Returns: str: The fully-qualified document path. """ parts = (client._database_string, "documents") + path return _helpers.DOCUMENT_PATH_DELIMITER.join(parts) def _consume_single_get(response_iterator): """Consume a gRPC stream that should contain a single response. The stream will correspond to a ``BatchGetDocuments`` request made for a single document. Args: response_iterator (~google.cloud.exceptions.GrpcRendezvous): A streaming iterator returned from a ``BatchGetDocuments`` request. Returns: ~google.cloud.proto.firestore.v1beta1.\ firestore_pb2.BatchGetDocumentsResponse: The single "get" response in the batch. Raises: ValueError: If anything other than exactly one response is returned. """ # Calling ``list()`` consumes the entire iterator. all_responses = list(response_iterator) if len(all_responses) != 1: raise ValueError( "Unexpected response from `BatchGetDocumentsResponse`", all_responses, "Expected only one result", ) return all_responses[0] def _first_write_result(write_results): """Get first write result from list. For cases where ``len(write_results) > 1``, this assumes the writes occurred at the same time (e.g. if an update and transform are sent at the same time). Args: write_results (List[google.cloud.proto.firestore.v1beta1.\ write_pb2.WriteResult, ...]: The write results from a ``CommitResponse``. Returns: google.cloud.firestore_v1beta1.types.WriteResult: The lone write result from ``write_results``. Raises: ValueError: If there are zero write results. This is likely to **never** occur, since the backend should be stable. """ if not write_results: raise ValueError("Expected at least one write result") return write_results[0] def _item_to_collection_ref(iterator, item): """Convert collection ID to collection ref. Args: iterator (google.api_core.page_iterator.GRPCIterator): iterator response item (str): ID of the collection """ return iterator.document.collection(item)