Source code for sqlalchemy_utils.types.color

from sqlalchemy import types

from ..exceptions import ImproperlyConfigured
from .scalar_coercible import ScalarCoercible

colour = None
    import colour
    python_colour_type = colour.Color
except (ImportError, AttributeError):
    python_colour_type = None

[docs]class ColorType(ScalarCoercible, types.TypeDecorator): """ ColorType provides a way for saving Color (from colour_ package) objects into database. ColorType saves Color objects as strings on the way in and converts them back to objects when querying the database. :: from colour import Color from sqlalchemy_utils import ColorType class Document(Base): __tablename__ = 'document' id = sa.Column(sa.Integer, autoincrement=True) name = sa.Column(sa.Unicode(50)) background_color = sa.Column(ColorType) document = Document() document.background_color = Color('#F5F5F5') session.commit() Querying the database returns Color objects: :: document = session.query(Document).first() document.background_color.hex # '#f5f5f5' .. _colour: """ STORE_FORMAT = 'hex' impl = types.Unicode(20) python_type = python_colour_type cache_ok = True def __init__(self, max_length=20, *args, **kwargs): # Fail if colour is not found. if colour is None: raise ImproperlyConfigured( "'colour' package is required to use 'ColorType'" ) super().__init__(*args, **kwargs) self.impl = types.Unicode(max_length) def process_bind_param(self, value, dialect): if value and isinstance(value, colour.Color): return str(getattr(value, self.STORE_FORMAT)) return value def process_result_value(self, value, dialect): if value: return colour.Color(value) return value def _coerce(self, value): if value is not None and not isinstance(value, colour.Color): return colour.Color(value) return value