372 lines
11 KiB
Python
372 lines
11 KiB
Python
import datetime
|
|
import json
|
|
|
|
from psycopg2.extras import DateRange, DateTimeTZRange, NumericRange, Range
|
|
|
|
from django.contrib.postgres import forms, lookups
|
|
from django.db import models
|
|
from django.db.models.lookups import PostgresOperatorLookup
|
|
|
|
from .utils import AttributeSetter
|
|
|
|
__all__ = [
|
|
"RangeField",
|
|
"IntegerRangeField",
|
|
"BigIntegerRangeField",
|
|
"DecimalRangeField",
|
|
"DateTimeRangeField",
|
|
"DateRangeField",
|
|
"RangeBoundary",
|
|
"RangeOperators",
|
|
]
|
|
|
|
|
|
class RangeBoundary(models.Expression):
|
|
"""A class that represents range boundaries."""
|
|
|
|
def __init__(self, inclusive_lower=True, inclusive_upper=False):
|
|
self.lower = "[" if inclusive_lower else "("
|
|
self.upper = "]" if inclusive_upper else ")"
|
|
|
|
def as_sql(self, compiler, connection):
|
|
return "'%s%s'" % (self.lower, self.upper), []
|
|
|
|
|
|
class RangeOperators:
|
|
# https://www.postgresql.org/docs/current/functions-range.html#RANGE-OPERATORS-TABLE
|
|
EQUAL = "="
|
|
NOT_EQUAL = "<>"
|
|
CONTAINS = "@>"
|
|
CONTAINED_BY = "<@"
|
|
OVERLAPS = "&&"
|
|
FULLY_LT = "<<"
|
|
FULLY_GT = ">>"
|
|
NOT_LT = "&>"
|
|
NOT_GT = "&<"
|
|
ADJACENT_TO = "-|-"
|
|
|
|
|
|
class RangeField(models.Field):
|
|
empty_strings_allowed = False
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
if "default_bounds" in kwargs:
|
|
raise TypeError(
|
|
f"Cannot use 'default_bounds' with {self.__class__.__name__}."
|
|
)
|
|
# Initializing base_field here ensures that its model matches the model
|
|
# for self.
|
|
if hasattr(self, "base_field"):
|
|
self.base_field = self.base_field()
|
|
super().__init__(*args, **kwargs)
|
|
|
|
@property
|
|
def model(self):
|
|
try:
|
|
return self.__dict__["model"]
|
|
except KeyError:
|
|
raise AttributeError(
|
|
"'%s' object has no attribute 'model'" % self.__class__.__name__
|
|
)
|
|
|
|
@model.setter
|
|
def model(self, model):
|
|
self.__dict__["model"] = model
|
|
self.base_field.model = model
|
|
|
|
@classmethod
|
|
def _choices_is_value(cls, value):
|
|
return isinstance(value, (list, tuple)) or super()._choices_is_value(value)
|
|
|
|
def get_placeholder(self, value, compiler, connection):
|
|
return "%s::{}".format(self.db_type(connection))
|
|
|
|
def get_prep_value(self, value):
|
|
if value is None:
|
|
return None
|
|
elif isinstance(value, Range):
|
|
return value
|
|
elif isinstance(value, (list, tuple)):
|
|
return self.range_type(value[0], value[1])
|
|
return value
|
|
|
|
def to_python(self, value):
|
|
if isinstance(value, str):
|
|
# Assume we're deserializing
|
|
vals = json.loads(value)
|
|
for end in ("lower", "upper"):
|
|
if end in vals:
|
|
vals[end] = self.base_field.to_python(vals[end])
|
|
value = self.range_type(**vals)
|
|
elif isinstance(value, (list, tuple)):
|
|
value = self.range_type(value[0], value[1])
|
|
return value
|
|
|
|
def set_attributes_from_name(self, name):
|
|
super().set_attributes_from_name(name)
|
|
self.base_field.set_attributes_from_name(name)
|
|
|
|
def value_to_string(self, obj):
|
|
value = self.value_from_object(obj)
|
|
if value is None:
|
|
return None
|
|
if value.isempty:
|
|
return json.dumps({"empty": True})
|
|
base_field = self.base_field
|
|
result = {"bounds": value._bounds}
|
|
for end in ("lower", "upper"):
|
|
val = getattr(value, end)
|
|
if val is None:
|
|
result[end] = None
|
|
else:
|
|
obj = AttributeSetter(base_field.attname, val)
|
|
result[end] = base_field.value_to_string(obj)
|
|
return json.dumps(result)
|
|
|
|
def formfield(self, **kwargs):
|
|
kwargs.setdefault("form_class", self.form_field)
|
|
return super().formfield(**kwargs)
|
|
|
|
|
|
CANONICAL_RANGE_BOUNDS = "[)"
|
|
|
|
|
|
class ContinuousRangeField(RangeField):
|
|
"""
|
|
Continuous range field. It allows specifying default bounds for list and
|
|
tuple inputs.
|
|
"""
|
|
|
|
def __init__(self, *args, default_bounds=CANONICAL_RANGE_BOUNDS, **kwargs):
|
|
if default_bounds not in ("[)", "(]", "()", "[]"):
|
|
raise ValueError("default_bounds must be one of '[)', '(]', '()', or '[]'.")
|
|
self.default_bounds = default_bounds
|
|
super().__init__(*args, **kwargs)
|
|
|
|
def get_prep_value(self, value):
|
|
if isinstance(value, (list, tuple)):
|
|
return self.range_type(value[0], value[1], self.default_bounds)
|
|
return super().get_prep_value(value)
|
|
|
|
def formfield(self, **kwargs):
|
|
kwargs.setdefault("default_bounds", self.default_bounds)
|
|
return super().formfield(**kwargs)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super().deconstruct()
|
|
if self.default_bounds and self.default_bounds != CANONICAL_RANGE_BOUNDS:
|
|
kwargs["default_bounds"] = self.default_bounds
|
|
return name, path, args, kwargs
|
|
|
|
|
|
class IntegerRangeField(RangeField):
|
|
base_field = models.IntegerField
|
|
range_type = NumericRange
|
|
form_field = forms.IntegerRangeField
|
|
|
|
def db_type(self, connection):
|
|
return "int4range"
|
|
|
|
|
|
class BigIntegerRangeField(RangeField):
|
|
base_field = models.BigIntegerField
|
|
range_type = NumericRange
|
|
form_field = forms.IntegerRangeField
|
|
|
|
def db_type(self, connection):
|
|
return "int8range"
|
|
|
|
|
|
class DecimalRangeField(ContinuousRangeField):
|
|
base_field = models.DecimalField
|
|
range_type = NumericRange
|
|
form_field = forms.DecimalRangeField
|
|
|
|
def db_type(self, connection):
|
|
return "numrange"
|
|
|
|
|
|
class DateTimeRangeField(ContinuousRangeField):
|
|
base_field = models.DateTimeField
|
|
range_type = DateTimeTZRange
|
|
form_field = forms.DateTimeRangeField
|
|
|
|
def db_type(self, connection):
|
|
return "tstzrange"
|
|
|
|
|
|
class DateRangeField(RangeField):
|
|
base_field = models.DateField
|
|
range_type = DateRange
|
|
form_field = forms.DateRangeField
|
|
|
|
def db_type(self, connection):
|
|
return "daterange"
|
|
|
|
|
|
RangeField.register_lookup(lookups.DataContains)
|
|
RangeField.register_lookup(lookups.ContainedBy)
|
|
RangeField.register_lookup(lookups.Overlap)
|
|
|
|
|
|
class DateTimeRangeContains(PostgresOperatorLookup):
|
|
"""
|
|
Lookup for Date/DateTimeRange containment to cast the rhs to the correct
|
|
type.
|
|
"""
|
|
|
|
lookup_name = "contains"
|
|
postgres_operator = RangeOperators.CONTAINS
|
|
|
|
def process_rhs(self, compiler, connection):
|
|
# Transform rhs value for db lookup.
|
|
if isinstance(self.rhs, datetime.date):
|
|
value = models.Value(self.rhs)
|
|
self.rhs = value.resolve_expression(compiler.query)
|
|
return super().process_rhs(compiler, connection)
|
|
|
|
def as_postgresql(self, compiler, connection):
|
|
sql, params = super().as_postgresql(compiler, connection)
|
|
# Cast the rhs if needed.
|
|
cast_sql = ""
|
|
if (
|
|
isinstance(self.rhs, models.Expression)
|
|
and self.rhs._output_field_or_none
|
|
and
|
|
# Skip cast if rhs has a matching range type.
|
|
not isinstance(
|
|
self.rhs._output_field_or_none, self.lhs.output_field.__class__
|
|
)
|
|
):
|
|
cast_internal_type = self.lhs.output_field.base_field.get_internal_type()
|
|
cast_sql = "::{}".format(connection.data_types.get(cast_internal_type))
|
|
return "%s%s" % (sql, cast_sql), params
|
|
|
|
|
|
DateRangeField.register_lookup(DateTimeRangeContains)
|
|
DateTimeRangeField.register_lookup(DateTimeRangeContains)
|
|
|
|
|
|
class RangeContainedBy(PostgresOperatorLookup):
|
|
lookup_name = "contained_by"
|
|
type_mapping = {
|
|
"smallint": "int4range",
|
|
"integer": "int4range",
|
|
"bigint": "int8range",
|
|
"double precision": "numrange",
|
|
"numeric": "numrange",
|
|
"date": "daterange",
|
|
"timestamp with time zone": "tstzrange",
|
|
}
|
|
postgres_operator = RangeOperators.CONTAINED_BY
|
|
|
|
def process_rhs(self, compiler, connection):
|
|
rhs, rhs_params = super().process_rhs(compiler, connection)
|
|
# Ignore precision for DecimalFields.
|
|
db_type = self.lhs.output_field.cast_db_type(connection).split("(")[0]
|
|
cast_type = self.type_mapping[db_type]
|
|
return "%s::%s" % (rhs, cast_type), rhs_params
|
|
|
|
def process_lhs(self, compiler, connection):
|
|
lhs, lhs_params = super().process_lhs(compiler, connection)
|
|
if isinstance(self.lhs.output_field, models.FloatField):
|
|
lhs = "%s::numeric" % lhs
|
|
elif isinstance(self.lhs.output_field, models.SmallIntegerField):
|
|
lhs = "%s::integer" % lhs
|
|
return lhs, lhs_params
|
|
|
|
def get_prep_lookup(self):
|
|
return RangeField().get_prep_value(self.rhs)
|
|
|
|
|
|
models.DateField.register_lookup(RangeContainedBy)
|
|
models.DateTimeField.register_lookup(RangeContainedBy)
|
|
models.IntegerField.register_lookup(RangeContainedBy)
|
|
models.FloatField.register_lookup(RangeContainedBy)
|
|
models.DecimalField.register_lookup(RangeContainedBy)
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class FullyLessThan(PostgresOperatorLookup):
|
|
lookup_name = "fully_lt"
|
|
postgres_operator = RangeOperators.FULLY_LT
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class FullGreaterThan(PostgresOperatorLookup):
|
|
lookup_name = "fully_gt"
|
|
postgres_operator = RangeOperators.FULLY_GT
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class NotLessThan(PostgresOperatorLookup):
|
|
lookup_name = "not_lt"
|
|
postgres_operator = RangeOperators.NOT_LT
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class NotGreaterThan(PostgresOperatorLookup):
|
|
lookup_name = "not_gt"
|
|
postgres_operator = RangeOperators.NOT_GT
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class AdjacentToLookup(PostgresOperatorLookup):
|
|
lookup_name = "adjacent_to"
|
|
postgres_operator = RangeOperators.ADJACENT_TO
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class RangeStartsWith(models.Transform):
|
|
lookup_name = "startswith"
|
|
function = "lower"
|
|
|
|
@property
|
|
def output_field(self):
|
|
return self.lhs.output_field.base_field
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class RangeEndsWith(models.Transform):
|
|
lookup_name = "endswith"
|
|
function = "upper"
|
|
|
|
@property
|
|
def output_field(self):
|
|
return self.lhs.output_field.base_field
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class IsEmpty(models.Transform):
|
|
lookup_name = "isempty"
|
|
function = "isempty"
|
|
output_field = models.BooleanField()
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class LowerInclusive(models.Transform):
|
|
lookup_name = "lower_inc"
|
|
function = "LOWER_INC"
|
|
output_field = models.BooleanField()
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class LowerInfinite(models.Transform):
|
|
lookup_name = "lower_inf"
|
|
function = "LOWER_INF"
|
|
output_field = models.BooleanField()
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class UpperInclusive(models.Transform):
|
|
lookup_name = "upper_inc"
|
|
function = "UPPER_INC"
|
|
output_field = models.BooleanField()
|
|
|
|
|
|
@RangeField.register_lookup
|
|
class UpperInfinite(models.Transform):
|
|
lookup_name = "upper_inf"
|
|
function = "UPPER_INF"
|
|
output_field = models.BooleanField()
|