119 lines
4.2 KiB
Python
119 lines
4.2 KiB
Python
# w.c.s. - web application for online forms
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# Copyright (C) 2005-2018 Entr'ouvert
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, see <http://www.gnu.org/licenses/>.
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import django.template.smartif
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from django.template import Context, Template, TemplateSyntaxError
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from django.utils.encoding import force_text
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from quixote import get_publisher
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from .qommon import _, force_str, get_logger
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class ValidationError(ValueError):
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pass
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class Condition:
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record_errors = True
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log_errors = False
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def __init__(self, condition, context=None):
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if not condition:
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condition = {}
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self.type = condition.get('type')
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self.value = condition.get('value')
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self.context = context or {}
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def __repr__(self):
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return '<%s (%s) %r>' % (self.__class__.__name__, self.type, self.value)
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def get_data(self):
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return get_publisher().substitutions.get_context_variables(mode='%s-condition' % self.type)
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def unsafe_evaluate(self):
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if not self.type or not self.value:
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return True
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local_variables = self.get_data()
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return getattr(self, 'evaluate_' + self.type)(local_variables)
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def evaluate(self):
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try:
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return self.unsafe_evaluate()
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except Exception as e:
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if self.log_errors:
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get_logger().warning('failed to evaluate %r (%r)', self, e)
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if self.record_errors:
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summary = _('Failed to evaluate condition')
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get_publisher().record_error(
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summary,
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formdata=self.context.get('formdata'),
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status_item=self.context.get('status_item'),
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expression=self.value,
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expression_type=self.type,
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exception=e,
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)
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raise RuntimeError()
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def evaluate_python(self, local_variables):
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global_variables = get_publisher().get_global_eval_dict()
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return eval(self.value, global_variables, local_variables)
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def evaluate_django(self, local_variables):
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template = Template('{%% if %s %%}OK{%% endif %%}' % self.value)
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context = Context(local_variables)
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return template.render(context) == 'OK'
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def validate(self):
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if not self.type or not self.value:
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return
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if not hasattr(self, 'validate_' + self.type):
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raise ValidationError(_('unknown condition type'))
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return getattr(self, 'validate_' + self.type)()
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def validate_python(self):
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if '{{' in self.value:
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raise ValidationError(_('invalid usage, Python condition cannot contain {{'))
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try:
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compile(self.value, '<string>', 'eval')
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except (SyntaxError, TypeError) as e:
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raise ValidationError(_('syntax error: %s') % force_str(force_text(e)))
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def validate_django(self):
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try:
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Template('{%% if %s %%}OK{%% endif %%}' % self.value)
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except (TemplateSyntaxError, OverflowError) as e:
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raise ValidationError(_('syntax error: %s') % force_str(force_text(e)))
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# add support for "in" and "not in" operators with left operand being a lazy
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# value.
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def lazy_eval(context, x):
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x = x.eval(context)
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if hasattr(x, 'get_value'):
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x = x.get_value()
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return x
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django.template.smartif.OPERATORS['in'] = django.template.smartif.infix(
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django.template.smartif.OPERATORS['in'].lbp,
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lambda context, x, y: lazy_eval(context, x) in y.eval(context),
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)
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django.template.smartif.OPERATORS['not in'] = django.template.smartif.infix(
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django.template.smartif.OPERATORS['not in'].lbp,
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lambda context, x, y: lazy_eval(context, x) not in y.eval(context),
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)
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