Fixed #24001 -- Added range fields for PostgreSQL.

Added support for PostgreSQL range types to contrib.postgres.

- 5 new model fields
- 4 new form fields
- New validators
- Uses psycopg2's range type implementation in python

5 files changed, 241 insertions, 1 deletions

diff --git a/django/contrib/postgres/fields/__init__.py b/django/contrib/postgres/fields/__init__.py
index 63a0c2c952..bb2685eca1 100644
--- a/django/contrib/postgres/fields/__init__.py
+++ b/django/contrib/postgres/fields/__init__.py
@@ -1,2 +1,3 @@
 from .array import *  # NOQA
 from .hstore import *  # NOQA
+from .ranges import *  # NOQA
diff --git a/django/contrib/postgres/fields/ranges.py b/django/contrib/postgres/fields/ranges.py
new file mode 100644
index 0000000000..8cb5229593
--- /dev/null
+++ b/django/contrib/postgres/fields/ranges.py
@@ -0,0 +1,156 @@
+import json
+
+from django.contrib.postgres import lookups, forms
+from django.db import models
+from django.utils import six
+
+from psycopg2.extras import Range, NumericRange, DateRange, DateTimeTZRange
+
+
+__all__ = [
+    'RangeField', 'IntegerRangeField', 'BigIntegerRangeField',
+    'FloatRangeField', 'DateTimeRangeField', 'DateRangeField',
+]
+
+
+class RangeField(models.Field):
+    empty_strings_allowed = False
+
+    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, six.string_types):
+            value = self.range_type(**json.loads(value))
+        elif isinstance(value, (list, tuple)):
+            value = self.range_type(value[0], value[1])
+        return value
+
+    def value_to_string(self, obj):
+        value = self._get_val_from_obj(obj)
+        if value is None:
+            return None
+        if value.isempty:
+            return json.dumps({"empty": True})
+        return json.dumps({
+            "lower": value.lower,
+            "upper": value.upper,
+            "bounds": value._bounds,
+        })
+
+    def formfield(self, **kwargs):
+        kwargs.setdefault('form_class', self.form_field)
+        return super(RangeField, self).formfield(**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 FloatRangeField(RangeField):
+    base_field = models.FloatField()
+    range_type = NumericRange
+    form_field = forms.FloatRangeField
+
+    def db_type(self, connection):
+        return 'numrange'
+
+
+class DateTimeRangeField(RangeField):
+    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)
+
+
+@RangeField.register_lookup
+class FullyLessThan(lookups.PostgresSimpleLookup):
+    lookup_name = 'fully_lt'
+    operator = '<<'
+
+
+@RangeField.register_lookup
+class FullGreaterThan(lookups.PostgresSimpleLookup):
+    lookup_name = 'fully_gt'
+    operator = '>>'
+
+
+@RangeField.register_lookup
+class NotLessThan(lookups.PostgresSimpleLookup):
+    lookup_name = 'not_lt'
+    operator = '&>'
+
+
+@RangeField.register_lookup
+class NotGreaterThan(lookups.PostgresSimpleLookup):
+    lookup_name = 'not_gt'
+    operator = '&<'
+
+
+@RangeField.register_lookup
+class AdjacentToLookup(lookups.PostgresSimpleLookup):
+    lookup_name = 'adjacent_to'
+    operator = '-|-'
+
+
+@RangeField.register_lookup
+class RangeStartsWith(lookups.FunctionTransform):
+    lookup_name = 'startswith'
+    function = 'lower'
+
+    @property
+    def output_field(self):
+        return self.lhs.output_field.base_field
+
+
+@RangeField.register_lookup
+class RangeEndsWith(lookups.FunctionTransform):
+    lookup_name = 'endswith'
+    function = 'upper'
+
+    @property
+    def output_field(self):
+        return self.lhs.output_field.base_field
+
+
+@RangeField.register_lookup
+class IsEmpty(lookups.FunctionTransform):
+    lookup_name = 'isempty'
+    function = 'isempty'
+    output_field = models.BooleanField()
diff --git a/django/contrib/postgres/forms/__init__.py b/django/contrib/postgres/forms/__init__.py
index 63a0c2c952..bb2685eca1 100644
--- a/django/contrib/postgres/forms/__init__.py
+++ b/django/contrib/postgres/forms/__init__.py
@@ -1,2 +1,3 @@
 from .array import *  # NOQA
 from .hstore import *  # NOQA
+from .ranges import *  # NOQA
diff --git a/django/contrib/postgres/forms/ranges.py b/django/contrib/postgres/forms/ranges.py
new file mode 100644
index 0000000000..4f8989a96d
--- /dev/null
+++ b/django/contrib/postgres/forms/ranges.py
@@ -0,0 +1,69 @@
+from django.core import exceptions
+from django import forms
+from django.utils.translation import ugettext_lazy as _
+
+from psycopg2.extras import NumericRange, DateRange, DateTimeTZRange
+
+
+__all__ = ['IntegerRangeField', 'FloatRangeField', 'DateTimeRangeField', 'DateRangeField']
+
+
+class BaseRangeField(forms.MultiValueField):
+    default_error_messages = {
+        'invalid': _('Enter two valid values.'),
+        'bound_ordering': _('The start of the range must not exceed the end of the range.'),
+    }
+
+    def __init__(self, **kwargs):
+        widget = forms.MultiWidget([self.base_field.widget, self.base_field.widget])
+        kwargs.setdefault('widget', widget)
+        kwargs.setdefault('fields', [self.base_field(required=False), self.base_field(required=False)])
+        kwargs.setdefault('required', False)
+        kwargs.setdefault('require_all_fields', False)
+        super(BaseRangeField, self).__init__(**kwargs)
+
+    def prepare_value(self, value):
+        if isinstance(value, self.range_type):
+            return [value.lower, value.upper]
+        if value is None:
+            return [None, None]
+        return value
+
+    def compress(self, values):
+        if not values:
+            return None
+        lower, upper = values
+        if lower is not None and upper is not None and lower > upper:
+            raise exceptions.ValidationError(
+                self.error_messages['bound_ordering'],
+                code='bound_ordering',
+            )
+        try:
+            range_value = self.range_type(lower, upper)
+        except TypeError:
+            raise exceptions.ValidationError(
+                self.error_messages['invalid'],
+                code='invalid',
+            )
+        else:
+            return range_value
+
+
+class IntegerRangeField(BaseRangeField):
+    base_field = forms.IntegerField
+    range_type = NumericRange
+
+
+class FloatRangeField(BaseRangeField):
+    base_field = forms.FloatField
+    range_type = NumericRange
+
+
+class DateTimeRangeField(BaseRangeField):
+    base_field = forms.DateTimeField
+    range_type = DateTimeTZRange
+
+
+class DateRangeField(BaseRangeField):
+    base_field = forms.DateField
+    range_type = DateRange
diff --git a/django/contrib/postgres/validators.py b/django/contrib/postgres/validators.py
index 19d0a69765..49ec921db1 100644
--- a/django/contrib/postgres/validators.py
+++ b/django/contrib/postgres/validators.py
@@ -1,7 +1,10 @@
 import copy
 
 from django.core.exceptions import ValidationError
-from django.core.validators import MaxLengthValidator, MinLengthValidator
+from django.core.validators import (
+    MaxLengthValidator, MinLengthValidator, MaxValueValidator,
+    MinValueValidator,
+)
 from django.utils.deconstruct import deconstructible
 from django.utils.translation import ungettext_lazy, ugettext_lazy as _
 
@@ -63,3 +66,13 @@ class KeysValidator(object):
 
     def __ne__(self, other):
         return not (self == other)
+
+
+class RangeMaxValueValidator(MaxValueValidator):
+    compare = lambda self, a, b: a.upper > b
+    message = _('Ensure that this range is completely less than or equal to %(limit_value)s.')
+
+
+class RangeMinValueValidator(MinValueValidator):
+    compare = lambda self, a, b: a.lower < b
+    message = _('Ensure that this range is completely greater than or equal to %(limit_value)s.')