def _normalize_cursor(cursor, orders):
"""Helper: convert cursor to a list of values based on orders."""
if cursor is None:
return
if not orders:
raise ValueError(_NO_ORDERS_FOR_CURSOR)
document_fields, before = cursor
order_keys = [order.field.field_path for order in orders]
if isinstance(document_fields, dict):
# Transform to list using orders
values = []
data = document_fields
for order_key in order_keys:
try:
values.append(_helpers.get_nested_value(order_key, data))
except KeyError:
msg = _MISSING_ORDER_BY.format(order_key, data)
raise ValueError(msg)
document_fields = values
if len(document_fields) != len(orders):
msg = _MISMATCH_CURSOR_W_ORDER_BY.format(document_fields, order_keys)
raise ValueError(msg)
_transform_bases = (transforms.Sentinel, transforms._ValueList)
for field in document_fields:
if isinstance(field, _transform_bases):
msg = _INVALID_CURSOR_TRANSFORM
raise ValueError(msg)
return document_fields, before
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:`~.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: (A copy of) the value stored for the ``field_path``.
Raises:
KeyError: If the ``field_path`` does not match nested data
in the snapshot.
"""
nested_data = _helpers.get_nested_value(field_path, self._data)
return copy.deepcopy(nested_data)
def _cursor_pb(cursor_pair, orders):
"""Convert a cursor pair to a protobuf.
If ``cursor_pair`` is :data:`None`, just returns :data:`None`.
Args:
cursor_pair (Optional[Tuple[dict, bool]]): Two-tuple of
* a mapping of fields. Any field that is present in this mapping
must also be present in ``orders``
* a ``before`` flag
orders (Tuple[google.cloud.proto.firestore.v1beta1.\
query_pb2.StructuredQuery.Order, ...]]): The "order by" entries
to use for a query. (We use this rather than a list of field path
strings just because it is how a query stores calls
to ``order_by``.)
Returns:
Optional[google.cloud.firestore_v1beta1.types.Cursor]: A
protobuf cursor corresponding to the values.
Raises:
ValueError: If ``cursor_pair`` is not :data:`None`, but there are
no ``orders``.
ValueError: If one of the field paths in ``orders`` is not contained
in the ``data`` (i.e. the first component of ``cursor_pair``).
"""
if cursor_pair is None:
return None
if len(orders) == 0:
raise ValueError(_NO_ORDERS_FOR_CURSOR)
data, before = cursor_pair
value_pbs = []
for order in orders:
field_path = order.field.field_path
try:
value = _helpers.get_nested_value(field_path, data)
except KeyError:
msg = _MISSING_ORDER_BY.format(field_path, data)
raise ValueError(msg)
value_pb = _helpers.encode_value(value)
value_pbs.append(value_pb)
return query_pb2.Cursor(values=value_pbs, before=before)
def _normalize_cursor(self, cursor, orders):
"""Helper: convert cursor to a list of values based on orders."""
if cursor is None:
return
if not orders:
raise ValueError(_NO_ORDERS_FOR_CURSOR)
document_fields, before = cursor
order_keys = [order.field.field_path for order in orders]
if isinstance(document_fields, dict):
# Transform to list using orders
values = []
data = document_fields
for order_key in order_keys:
try:
values.append(_helpers.get_nested_value(order_key, data))
except KeyError:
msg = _MISSING_ORDER_BY.format(order_key, data)
raise ValueError(msg)
document_fields = values
if len(document_fields) != len(orders):
msg = _MISMATCH_CURSOR_W_ORDER_BY.format(document_fields,
order_keys)
raise ValueError(msg)
_transform_bases = (transforms.Sentinel, transforms._ValueList)
for index, key_field in enumerate(zip(order_keys, document_fields)):
key, field = key_field
if isinstance(field, _transform_bases):
msg = _INVALID_CURSOR_TRANSFORM
raise ValueError(msg)
if key == "__name__" and "/" not in field:
document_fields[index] = "{}/{}/{}".format(
self._client._database_string,
"/".join(self._parent._path), field)
return document_fields, before
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:`~.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 = _helpers.get_nested_value(field_path, self._data)
return copy.deepcopy(nested_data)
def _call_fut(field_path, data):
from google.cloud.firestore_v1beta1._helpers import get_nested_value
return get_nested_value(field_path, data)
