deb-murano/murano/dsl/yaql_expression.py
Stan Lagun 9a9f3436e1 Version-aware YAML loading
* Refactoring of "packages" Python package
* Now MuranoPL YAML classes can be parsed by different engines
depending on Format string in package manifest

With this change MuranoPL classes will no longer
be read and parsed (including YAQL expressions parsing)
upon package load but only on first class access and
with ability to peak different parsers depending on
format version specified in manifest. As a consequence
it is now possible to use different YAQL engines for
different package format versions. Also startup
time was greatly improved as unneeded classes are no more
parsed and logos and UI forms are not loaded.

Partially implements: blueprint murano-versioning

Change-Id: I23fc5da1a43b405d526438329dc04aed589dee13
2015-09-03 12:07:13 +00:00

84 lines
2.8 KiB
Python

# Copyright (c) 2014 Mirantis, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import re
import types
from oslo_utils import encodeutils
from yaql.language import exceptions as yaql_exceptions
from yaql.language import expressions
from murano.dsl import constants
from murano.dsl import dsl_types
from murano.dsl import yaql_integration
class YaqlExpression(dsl_types.YaqlExpression):
def __init__(self, expression, version):
self._version = version
if isinstance(expression, types.StringTypes):
self._expression = encodeutils.safe_encode(expression)
self._parsed_expression = yaql_integration.parse(
self._expression, version)
self._file_position = None
elif isinstance(expression, YaqlExpression):
self._expression = expression._expression
self._parsed_expression = expression._parsed_expression
self._file_position = expression._file_position
elif isinstance(expression, expressions.Statement):
self._expression = unicode(expression)
self._parsed_expression = expression
self._file_position = None
else:
raise TypeError('expression is not of supported types')
@property
def expression(self):
return self._expression
@property
def version(self):
return self._version
@property
def source_file_position(self):
return self._file_position
@source_file_position.setter
def source_file_position(self, value):
self._file_position = value
def __repr__(self):
return 'YAQL(%s)' % self._expression
def __str__(self):
return self._expression
@staticmethod
def is_expression(expression, version):
if not isinstance(expression, types.StringTypes):
return False
if re.match('^[\s\w\d.:]*$', expression):
return False
try:
yaql_integration.parse(expression, version)
return True
except yaql_exceptions.YaqlParsingException:
return False
def __call__(self, context):
if context:
context[constants.CTX_CURRENT_INSTRUCTION] = self
return self._parsed_expression.evaluate(context=context)