tryton/tryton/gui/window/view_form/model/field.py

# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
import os
from itertools import chain
import tempfile
import locale
from tryton.common import \
        domain_inversion, eval_domain, localize_domain, \
        merge, inverse_leaf, filter_leaf, concat, simplify, unique_value, \
        EvalEnvironment
import tryton.common as common
import datetime
import decimal
from decimal import Decimal
import math
from tryton.common import RPCExecute, RPCException
import tryton.rpc as rpc


class Field(object):
    '''
    get: return the values to write to the server
    get_client: return the value for the client widget (form_gtk)
    set: save the value from the server
    set_client: save the value from the widget
    '''
    _default = None

    @staticmethod
    def get_field(ctype):
        return TYPES.get(ctype, CharField)

    def __init__(self, attrs):
        self.attrs = attrs
        self.name = attrs['name']

    def sig_changed(self, record):
        if self.get_state_attrs(record).get('readonly', False):
            return
        record.on_change([self.name])
        record.on_change_with([self.name])
        record.autocomplete_with(self.name)
        record.set_field_context()

    def domains_get(self, record, pre_validate=None):
        screen_domain = domain_inversion(
            [record.group.domain4inversion, pre_validate or []],
            self.name, EvalEnvironment(record))
        if isinstance(screen_domain, bool) and not screen_domain:
            screen_domain = [('id', '=', None)]
        elif isinstance(screen_domain, bool) and screen_domain:
            screen_domain = []
        attr_domain = record.expr_eval(self.attrs.get('domain', []))
        return screen_domain, attr_domain

    def domain_get(self, record):
        screen_domain, attr_domain = self.domains_get(record)
        return concat(localize_domain(screen_domain), attr_domain)

    def validation_domains(self, record, pre_validate=None):
        return concat(*self.domains_get(record, pre_validate))

    def context_get(self, record):
        context = record.context_get().copy()
        if record.parent:
            context.update(record.parent.context_get())
        context.update(record.expr_eval(self.attrs.get('context', {})))
        return context

    def check_required(self, record):
        state_attrs = self.get_state_attrs(record)
        if bool(int(state_attrs.get('required') or 0)):
            if (not self.get_eval(record)
                    and not bool(int(state_attrs.get('readonly') or 0))):
                return False
        return True

    def validate(self, record, softvalidation=False, pre_validate=None):
        if self.attrs.get('readonly'):
            return True
        invalid = False
        self.get_state_attrs(record)['domain_readonly'] = False
        domain = simplify(self.validation_domains(record, pre_validate))
        if not softvalidation:
            if not self.check_required(record):
                invalid = 'required'
        if isinstance(domain, bool):
            if not domain:
                invalid = 'domain'
        elif domain == [('id', '=', None)]:
            invalid = 'domain'
        else:
            unique, leftpart, value = unique_value(domain)
            if unique:
                # If the inverted domain is so constraint that only one value
                # is possible we should use it. But we must also pay attention
                # to the fact that the original domain might be a 'OR' domain
                # and thus not preventing the modification of fields.
                if value is False:
                    # XXX to remove once server domains are fixed
                    value = None
                setdefault = True
                if record.group.domain:
                    original_domain = merge(record.group.domain)
                else:
                    original_domain = merge(domain)
                domain_readonly = original_domain[0] == 'AND'
                if '.' in leftpart:
                    recordpart, localpart = leftpart.split('.', 1)
                    constraintfields = set()
                    if domain_readonly:
                        for leaf in localize_domain(original_domain[1:]):
                            constraintfields.add(leaf[0])
                    if localpart != 'id' or recordpart not in constraintfields:
                        setdefault = False
                if setdefault and not pre_validate:
                    self.set_client(record, value)
                    self.get_state_attrs(record)['domain_readonly'] = (
                        domain_readonly)
            if not eval_domain(domain, EvalEnvironment(record)):
                invalid = domain
        self.get_state_attrs(record)['invalid'] = invalid
        return not invalid

    def set(self, record, value):
        record.value[self.name] = value

    def get(self, record):
        return record.value.get(self.name, self._default)

    def get_eval(self, record):
        return self.get(record)

    def get_on_change_value(self, record):
        return self.get_eval(record)

    def set_client(self, record, value, force_change=False):
        previous_value = self.get(record)
        self.set(record, value)
        if previous_value != self.get(record):
            record.modified_fields.setdefault(self.name)
            record.signal('record-modified')
            self.sig_changed(record)
            record.validate(softvalidation=True)
            record.signal('record-changed')
        elif force_change:
            self.sig_changed(record)
            record.validate(softvalidation=True)
            record.signal('record-changed')

    def get_client(self, record):
        return self.get(record)

    def set_default(self, record, value):
        self.set(record, value)
        record.modified_fields.setdefault(self.name)

    def set_on_change(self, record, value):
        record.modified_fields.setdefault(self.name)
        self.set(record, value)

    def state_set(self, record, states=('readonly', 'required', 'invisible')):
        state_changes = record.expr_eval(self.attrs.get('states', {}))
        for key in states:
            if key == 'readonly' and self.attrs.get(key, False):
                continue
            if key in state_changes:
                self.get_state_attrs(record)[key] = state_changes[key]
            elif key in self.attrs:
                self.get_state_attrs(record)[key] = self.attrs[key]
        if (record.group.readonly
                or self.get_state_attrs(record).get('domain_readonly')):
            self.get_state_attrs(record)['readonly'] = True

    def get_state_attrs(self, record):
        if self.name not in record.state_attrs:
            record.state_attrs[self.name] = self.attrs.copy()
        if record.group.readonly or record.readonly:
            record.state_attrs[self.name]['readonly'] = True
        return record.state_attrs[self.name]

    def get_timestamp(self, record):
        return {}


class CharField(Field):
    _default = ''

    def get(self, record):
        return super(CharField, self).get(record) or self._default


class SelectionField(Field):

    _default = None

    def get_client(self, record):
        return record.value.get(self.name)


class DateTimeField(Field):

    _default = None

    def set_client(self, record, value, force_change=False):
        if isinstance(value, datetime.time):
            current_value = self.get_client(record)
            if current_value:
                value = datetime.datetime.combine(
                    current_value.date(), value)
            else:
                value = None
        elif value and not isinstance(value, datetime.datetime):
            current_value = self.get_client(record)
            if current_value:
                time = current_value.time()
            else:
                time = datetime.time()
            value = datetime.datetime.combine(value, time)
        if value:
            value = common.untimezoned_date(value)
        super(DateTimeField, self).set_client(record, value,
            force_change=force_change)

    def get_client(self, record):
        value = super(DateTimeField, self).get_client(record)
        if value:
            return common.timezoned_date(value)

    def date_format(self, record):
        context = self.context_get(record)
        return context.get('date_format', '%x')

    def time_format(self, record):
        return record.expr_eval(self.attrs['format'])


class DateField(Field):

    _default = None

    def set_client(self, record, value, force_change=False):
        if isinstance(value, datetime.datetime):
            assert(value.time() == datetime.time())
            value = value.date()
        super(DateField, self).set_client(record, value,
            force_change=force_change)

    def date_format(self, record):
        context = self.context_get(record)
        return context.get('date_format', '%x')


class TimeField(Field):

    _default = None

    def set_client(self, record, value, force_change=False):
        if isinstance(value, datetime.datetime):
            value = value.time()
        super(TimeField, self).set_client(record, value,
            force_change=force_change)

    def time_format(self, record):
        return record.expr_eval(self.attrs['format'])


class TimeDeltaField(Field):

    _default = None

    def converter(self, record):
        # TODO allow local context converter
        return rpc.CONTEXT.get(self.attrs.get('converter'))

    def set_client(self, record, value, force_change=False):
        if isinstance(value, basestring):
            value = common.timedelta.parse(value, self.converter(record))
        super(TimeDeltaField, self).set_client(
            record, value, force_change=force_change)

    def get_client(self, record):
        value = super(TimeDeltaField, self).get_client(record)
        return common.timedelta.format(value, self.converter(record))


class FloatField(Field):
    _default = None

    def check_required(self, record):
        state_attrs = self.get_state_attrs(record)
        if bool(int(state_attrs.get('required') or 0)):
            if (self.get(record) is None
                    and not bool(int(state_attrs.get('readonly') or 0))):
                return False
        return True

    def get(self, record):
        return record.value.get(self.name, self._default)

    def digits(self, record, factor=1):
        digits = record.expr_eval(self.attrs.get('digits'))
        if not digits or any(d is None for d in digits):
            return
        shift = int(round(math.log(abs(factor), 10)))
        return (digits[0] + shift, digits[1] - shift)

    def convert(self, value):
        try:
            return locale.atof(value)
        except ValueError:
            return self._default

    def set_client(self, record, value, force_change=False, factor=1):
        if isinstance(value, basestring):
            value = self.convert(value)
        if value is not None:
            value /= factor
        super(FloatField, self).set_client(record, value,
            force_change=force_change)

    def get_client(self, record, factor=1):
        value = record.value.get(self.name)
        if value is not None:
            digits = self.digits(record, factor=factor)
            if digits:
                p = digits[1]
            else:
                p = -int(Decimal(str(value * factor)).as_tuple().exponent)
            return locale.format('%.*f', (p, value * factor), True)
        else:
            return ''


class NumericField(FloatField):

    def convert(self, value):
        try:
            return locale.atof(value, Decimal)
        except decimal.InvalidOperation:
            return self._default

    def set_client(self, record, value, force_change=False, factor=1):
        return super(NumericField, self).set_client(record, value,
            force_change=force_change, factor=Decimal(str(factor)))

    def get_client(self, record, factor=1):
        return super(NumericField, self).get_client(record,
            factor=Decimal(str(factor)))


class IntegerField(FloatField):

    def convert(self, value):
        try:
            return locale.atoi(value)
        except ValueError:
            return self._default

    def set_client(self, record, value, force_change=False, factor=1):
        return super(IntegerField, self).set_client(record, value,
            force_change=force_change, factor=int(factor))

    def get_client(self, record, factor=1):
        return super(IntegerField, self).get_client(record, factor=int(factor))


class BooleanField(Field):

    _default = False

    def set_client(self, record, value, force_change=False):
        value = bool(value)
        super(BooleanField, self).set_client(record, value,
            force_change=force_change)

    def get(self, record):
        return bool(record.value.get(self.name))

    def get_client(self, record):
        return bool(record.value.get(self.name))


class M2OField(Field):
    '''
    internal = (id, name)
    '''

    _default = None

    def get_client(self, record):
        rec_name = record.value.get(self.name + '.rec_name')
        if rec_name is None:
            self.set(record, self.get(record))
            rec_name = record.value.get(self.name + '.rec_name') or ''
        return rec_name

    def set_client(self, record, value, force_change=False):
        if isinstance(value, (tuple, list)):
            value, rec_name = value
        else:
            if value == self.get(record):
                rec_name = record.value.get(self.name + '.rec_name', '')
            else:
                rec_name = ''
        record.value[self.name + '.rec_name'] = rec_name
        super(M2OField, self).set_client(record, value,
            force_change=force_change)

    def set(self, record, value):
        rec_name = record.value.get(self.name + '.rec_name') or ''
        if not rec_name and value >= 0:
            try:
                result, = RPCExecute('model', self.attrs['relation'], 'read',
                    [value], ['rec_name'])
            except RPCException:
                return
            rec_name = result['rec_name'] or ''
        record.value[self.name + '.rec_name'] = rec_name
        record.value[self.name] = value

    def context_get(self, record):
        context = super(M2OField, self).context_get(record)
        if self.attrs.get('datetime_field'):
            context['_datetime'] = record.get_eval(
                )[self.attrs.get('datetime_field')]
        return context

    def validation_domains(self, record, pre_validate=None):
        screen_domain, attr_domain = self.domains_get(record, pre_validate)
        return screen_domain

    def domain_get(self, record):
        screen_domain, attr_domain = self.domains_get(record)
        return concat(localize_domain(inverse_leaf(screen_domain), self.name),
            attr_domain)

    def get_on_change_value(self, record):
        if record.parent_name == self.name and record.parent:
            return record.parent.get_on_change_value(
                skip={record.group.child_name})
        return super(M2OField, self).get_on_change_value(record)


class O2OField(M2OField):
    pass


class O2MField(Field):
    '''
    internal = Group of the related objects
    '''

    _default = None

    def __init__(self, attrs):
        super(O2MField, self).__init__(attrs)

    def _group_changed(self, group, record):
        if not record.parent:
            return
        # Store parent as it could be removed by validation
        parent = record.parent
        parent.modified_fields.setdefault(self.name)
        self.sig_changed(parent)
        parent.validate(softvalidation=True)
        parent.signal('record-changed')

    def _group_list_changed(self, group, signal):
        if group.model_name == group.parent.model_name:
            group.parent.group.signal('group-list-changed', signal)

    def _group_cleared(self, group, signal):
        if group.model_name == group.parent.model_name:
            group.parent.signal('group-cleared')

    def _record_modified(self, group, record):
        if not record.parent:
            return
        record.parent.signal('record-modified')

    def _set_default_value(self, record, fields=None):
        if record.value.get(self.name) is not None:
            return
        from group import Group
        parent_name = self.attrs.get('relation_field', '')
        fields = fields or {}
        context = record.expr_eval(self.attrs.get('context', {}))
        group = Group(self.attrs['relation'], fields,
                parent=record,
                parent_name=parent_name,
                child_name=self.name,
                context=context,
                parent_datetime_field=self.attrs.get('datetime_field'))
        if not fields and record.model_name == self.attrs['relation']:
            group.fields = record.group.fields
        record.value[self.name] = group
        self._connect_value(group)

    def _connect_value(self, group):
        group.signal_connect(group, 'group-changed', self._group_changed)
        group.signal_connect(group, 'group-list-changed',
            self._group_list_changed)
        group.signal_connect(group, 'group-cleared', self._group_cleared)
        group.signal_connect(group, 'record-modified', self._record_modified)

    def get_client(self, record):
        self._set_default_value(record)
        return record.value.get(self.name)

    def get(self, record):
        if record.value.get(self.name) is None:
            return []
        record_removed = record.value[self.name].record_removed
        record_deleted = record.value[self.name].record_deleted
        result = []
        parent_name = self.attrs.get('relation_field', '')
        to_add = []
        to_create = []
        to_write = []
        for record2 in record.value[self.name]:
            if record2 in record_removed or record2 in record_deleted:
                continue
            if record2.id >= 0:
                values = record2.get()
                values.pop(parent_name, None)
                if record2.modified and values:
                    to_write.extend(([record2.id], values))
                to_add.append(record2.id)
            else:
                values = record2.get()
                values.pop(parent_name, None)
                to_create.append(values)
        if to_add:
            result.append(('add', to_add))
        if to_create:
            result.append(('create', to_create))
        if to_write:
            result.append(('write',) + tuple(to_write))
        if record_removed:
            result.append(('remove', [x.id for x in record_removed]))
        if record_deleted:
            result.append(('delete', [x.id for x in record_deleted]))
        return result

    def get_timestamp(self, record):
        if record.value.get(self.name) is None:
            return {}
        result = {}
        for record2 in (record.value[self.name]
                + record.value[self.name].record_removed
                + record.value[self.name].record_deleted):
            result.update(record2.get_timestamp())
        return result

    def get_eval(self, record):
        if record.value.get(self.name) is None:
            return []
        record_removed = record.value[self.name].record_removed
        record_deleted = record.value[self.name].record_deleted
        return [x.id for x in record.value[self.name]
            if x not in record_removed and x not in record_deleted]

    def get_on_change_value(self, record):
        result = []
        if record.value.get(self.name) is None:
            return []
        for record2 in record.value[self.name]:
            if not (record2.deleted or record2.removed):
                result.append(
                    record2.get_on_change_value(
                        skip={self.attrs.get('relation_field', '')}))
        return result

    def _set_value(self, record, value, default=False):
        self._set_default_value(record)
        group = record.value[self.name]
        if not value or (len(value) and isinstance(value[0], (int, long))):
            mode = 'list ids'
        else:
            mode = 'list values'

        if mode == 'list values' and len(value):
            context = self.context_get(record)
            field_names = set(f for v in value for f in v
                if f not in group.fields)
            if field_names:
                try:
                    fields = RPCExecute('model', self.attrs['relation'],
                        'fields_get', list(field_names), context=context)
                except RPCException:
                    return
                group.load_fields(fields)

        if mode == 'list ids':
            for old_record in group:
                if old_record.id not in value:
                    group.remove(old_record, remove=True, signal=False)
            group.load(value)
        else:
            for vals in value:
                new_record = record.value[self.name].new(default=False)
                if default:
                    new_record.set_default(vals)
                    group.add(new_record)
                else:
                    new_record.id *= -1  # Don't consider record as unsaved
                    new_record.set(vals)
                    group.append(new_record)

    def set(self, record, value, _default=False):
        group = record.value.get(self.name)
        fields = {}
        if group is not None:
            fields = group.fields.copy()
            # Unconnect to prevent infinite loop
            group.signal_unconnect(group)
            group.destroy()
        elif record.model_name == self.attrs['relation']:
            fields = record.group.fields
        if fields:
            fields = dict((fname, field.attrs)
                for fname, field in fields.iteritems())

        record.value[self.name] = None
        self._set_default_value(record, fields=fields)
        group = record.value[self.name]

        group.signal_unconnect(group)
        self._set_value(record, value, default=_default)
        self._connect_value(group)

    def set_client(self, record, value, force_change=False):
        # domain inversion could try to set None as value
        if value is None:
            value = []
        # domain inversion could try to set id as value
        if isinstance(value, (int, long)):
            value = [value]

        previous_ids = self.get_eval(record)
        self._set_value(record, value)
        # The order of the ids is not significant
        if set(previous_ids) != set(value):
            record.modified_fields.setdefault(self.name)
            record.signal('record-modified')
            self.sig_changed(record)
            record.validate(softvalidation=True)
            record.signal('record-changed')
        elif force_change:
            self.sig_changed(record)
            record.validate(softvalidation=True)
            record.signal('record-changed')

    def set_default(self, record, value):
        self.set(record, value, _default=True)
        record.modified_fields.setdefault(self.name)

    def set_on_change(self, record, value):
        record.modified_fields.setdefault(self.name)
        self._set_default_value(record)
        if isinstance(value, (list, tuple)):
            self._set_value(record, value)
            return

        if value and (value.get('add') or value.get('update')):
            context = self.context_get(record)
            fields = record.value[self.name].fields
            values = chain(value.get('update', []),
                (d for _, d in value.get('add', [])))
            field_names = set(f for v in values
                for f in v if f not in fields and f != 'id')
            if field_names:
                try:
                    fields = RPCExecute('model', self.attrs['relation'],
                        'fields_get', list(field_names), context=context)
                except RPCException:
                    return
            else:
                fields = {}

        to_remove = []
        for record2 in record.value[self.name]:
            if not record2.id:
                to_remove.append(record2)
        if value and value.get('remove'):
            for record_id in value['remove']:
                record2 = record.value[self.name].get(record_id)
                if record2 is not None:
                    to_remove.append(record2)
        for record2 in to_remove:
            record.value[self.name].remove(record2, signal=False,
                force_remove=False)

        if value and (value.get('add') or value.get('update', [])):
            record.value[self.name].add_fields(fields, signal=False)
            for index, vals in value.get('add', []):
                new_record = record.value[self.name].new(default=False)
                record.value[self.name].add(new_record, index, signal=False)
                new_record.set_on_change(vals)

            for vals in value.get('update', []):
                if 'id' not in vals:
                    continue
                record2 = record.value[self.name].get(vals['id'])
                if record2 is not None:
                    record2.set_on_change(vals)

    def validation_domains(self, record, pre_validate=None):
        screen_domain, attr_domain = self.domains_get(record, pre_validate)
        return screen_domain

    def validate(self, record, softvalidation=False, pre_validate=None):
        if self.attrs.get('readonly'):
            return True
        invalid = False
        ldomain = localize_domain(domain_inversion(
                record.group.clean4inversion(pre_validate or []), self.name,
                EvalEnvironment(record)), self.name)
        if isinstance(ldomain, bool):
            if ldomain:
                ldomain = []
            else:
                ldomain = [('id', '=', None)]
        for record2 in record.value.get(self.name, []):
            if not record2.loaded and record2.id >= 0 and not pre_validate:
                continue
            if not record2.validate(softvalidation=softvalidation,
                    pre_validate=ldomain):
                invalid = 'children'
        test = super(O2MField, self).validate(record, softvalidation,
            pre_validate)
        if test and invalid:
            self.get_state_attrs(record)['invalid'] = invalid
            return False
        return test

    def state_set(self, record, states=('readonly', 'required', 'invisible')):
        self._set_default_value(record)
        super(O2MField, self).state_set(record, states=states)
        record.value[self.name].readonly = self.get_state_attrs(record).get(
            'readonly', False)

    def get_removed_ids(self, record):
        return [x.id for x in record.value[self.name].record_removed]

    def domain_get(self, record):
        screen_domain, attr_domain = self.domains_get(record)
        return concat(localize_domain(inverse_leaf(screen_domain), self.name),
            attr_domain)


class M2MField(O2MField):

    def get_on_change_value(self, record):
        return self.get_eval(record)


class ReferenceField(Field):

    _default = None

    def get_client(self, record):
        if record.value.get(self.name):
            model, _ = record.value[self.name]
            name = record.value.get(self.name + '.rec_name') or ''
            return model, name
        else:
            return None

    def get(self, record):
        if (record.value.get(self.name)
                and record.value[self.name][0]
                and record.value[self.name][1] >= -1):
            return ','.join(map(str, record.value[self.name]))
        return None

    def set_client(self, record, value, force_change=False):
        if value:
            if isinstance(value, basestring):
                value = value.split(',')
            ref_model, ref_id = value
            if isinstance(ref_id, (tuple, list)):
                ref_id, rec_name = ref_id
            else:
                if ref_id:
                    try:
                        ref_id = int(ref_id)
                    except ValueError:
                        pass
                if '%s,%s' % (ref_model, ref_id) == self.get(record):
                    rec_name = record.value.get(self.name + '.rec_name', '')
                else:
                    rec_name = ''
            record.value[self.name + '.rec_name'] = rec_name
            value = (ref_model, ref_id)
        super(ReferenceField, self).set_client(record, value,
            force_change=force_change)

    def set(self, record, value):
        if not value:
            record.value[self.name] = self._default
            return
        if isinstance(value, basestring):
            ref_model, ref_id = value.split(',')
            if not ref_id:
                ref_id = None
            else:
                try:
                    ref_id = int(ref_id)
                except ValueError:
                    pass
        else:
            ref_model, ref_id = value
        rec_name = record.value.get(self.name + '.rec_name') or ''
        if ref_model and ref_id >= 0:
            if not rec_name and ref_id >= 0:
                try:
                    result, = RPCExecute('model', ref_model, 'read', [ref_id],
                        ['rec_name'])
                except RPCException:
                    return
                rec_name = result['rec_name']
        elif ref_model:
            rec_name = ''
        else:
            rec_name = str(ref_id)
        record.value[self.name] = ref_model, ref_id
        record.value[self.name + '.rec_name'] = rec_name

    def get_on_change_value(self, record):
        if record.parent_name == self.name and record.parent:
            return record.parent.model_name, record.parent.get_on_change_value(
                skip={record.group.child_name})
        return super(ReferenceField, self).get_on_change_value(record)

    def validation_domains(self, record, pre_validate=None):
        screen_domain, attr_domain = self.domains_get(record, pre_validate)
        return screen_domain

    def domain_get(self, record):
        if record.value.get(self.name):
            model = record.value[self.name][0]
        else:
            model = None
        screen_domain, attr_domain = self.domains_get(record)
        return concat(localize_domain(
                filter_leaf(screen_domain, self.name, model),
                strip_target=True), attr_domain)


class _FileCache(object):
    def __init__(self, path):
        self.path = path


class BinaryField(Field):

    _default = None
    cast = bytearray if bytes == str else bytes

    def get(self, record):
        result = record.value.get(self.name, self._default)
        if isinstance(result, _FileCache):
            try:
                with open(result.path, 'rb') as fp:
                    result = self.cast(fp.read())
            except IOError:
                result = self.get_data(record)
        return result

    def get_client(self, record):
        return self.get(record)

    def set_client(self, record, value, force_change=False):
        _, filename = tempfile.mkstemp(prefix='tryton_')
        with open(filename, 'wb') as fp:
            fp.write(value or '')
        self.set(record, _FileCache(filename))
        record.modified_fields.setdefault(self.name)
        record.signal('record-modified')
        self.sig_changed(record)
        record.validate(softvalidation=True)
        record.signal('record-changed')

    def get_size(self, record):
        result = record.value.get(self.name) or 0
        if isinstance(result, _FileCache):
            result = os.stat(result.path).st_size
        elif isinstance(result, (basestring, bytes, bytearray)):
            result = len(result)
        return result

    def get_data(self, record):
        if not isinstance(record.value.get(self.name),
                (basestring, bytes, bytearray)):
            if record.id < 0:
                return ''
            context = record.context_get()
            try:
                values, = RPCExecute('model', record.model_name, 'read',
                    [record.id], [self.name], context=context)
            except RPCException:
                return ''
            _, filename = tempfile.mkstemp(prefix='tryton_')
            with open(filename, 'wb') as fp:
                fp.write(values[self.name] or '')
            self.set(record, _FileCache(filename))
        return self.get(record)


class DictField(Field):

    _default = {}

    def get(self, record):
        return super(DictField, self).get(record) or self._default

    def get_client(self, record):
        return super(DictField, self).get_client(record) or self._default

    def validation_domains(self, record, pre_validate=None):
        screen_domain, attr_domain = self.domains_get(record, pre_validate)
        return screen_domain

    def domain_get(self, record):
        screen_domain, attr_domain = self.domains_get(record)
        return concat(localize_domain(inverse_leaf(screen_domain)),
            attr_domain)

    def date_format(self, record):
        context = self.context_get(record)
        return context.get('date_format', '%x')

    def time_format(self, record):
        return '%X'

TYPES = {
    'char': CharField,
    'integer': IntegerField,
    'biginteger': IntegerField,
    'float': FloatField,
    'numeric': NumericField,
    'many2one': M2OField,
    'many2many': M2MField,
    'one2many': O2MField,
    'reference': ReferenceField,
    'selection': SelectionField,
    'boolean': BooleanField,
    'datetime': DateTimeField,
    'date': DateField,
    'time': TimeField,
    'timedelta': TimeDeltaField,
    'one2one': O2OField,
    'binary': BinaryField,
    'dict': DictField,
}