# Copyright 2008-2015 Nokia Networks
# Copyright 2016- Robot Framework Foundation
#
# 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
from collections.abc import MutableSequence
from robot.errors import (DataError, ExecutionStatus, HandlerExecutionFailed,
VariableError)
from robot.utils import (DotDict, ErrorDetails, format_assign_message,
get_error_message, is_dict_like, is_list_like,
is_number, is_string, prepr, type_name)
from .search import search_variable, VariableMatch
[docs]class VariableAssignment:
def __init__(self, assignment):
validator = AssignmentValidator()
try:
self.assignment = [validator.validate(var) for var in assignment]
self.error = None
except DataError as err:
self.assignment = assignment
self.error = err
def __iter__(self):
return iter(self.assignment)
def __len__(self):
return len(self.assignment)
[docs] def validate_assignment(self):
if self.error:
raise self.error
[docs] def assigner(self, context):
self.validate_assignment()
return VariableAssigner(self.assignment, context)
[docs]class AssignmentValidator:
def __init__(self):
self._seen_list = False
self._seen_dict = False
self._seen_any_var = False
self._seen_assign_mark = False
[docs] def validate(self, variable):
variable = self._validate_assign_mark(variable)
self._validate_state(is_list=variable[0] == '@',
is_dict=variable[0] == '&')
return variable
def _validate_assign_mark(self, variable):
if self._seen_assign_mark:
raise DataError("Assign mark '=' can be used only with the last variable.",
syntax=True)
if variable.endswith('='):
self._seen_assign_mark = True
return variable[:-1].rstrip()
return variable
def _validate_state(self, is_list, is_dict):
if is_list and self._seen_list:
raise DataError('Assignment can contain only one list variable.',
syntax=True)
if self._seen_dict or is_dict and self._seen_any_var:
raise DataError('Dictionary variable cannot be assigned with other '
'variables.', syntax=True)
self._seen_list += is_list
self._seen_dict += is_dict
self._seen_any_var = True
[docs]class VariableAssigner:
_valid_extended_attr = re.compile(r'^[_a-zA-Z]\w*$')
def __init__(self, assignment, context):
self._assignment = assignment
self._context = context
def __enter__(self):
return self
def __exit__(self, etype, error, tb):
if error is None:
return
if not isinstance(error, ExecutionStatus):
error = HandlerExecutionFailed(ErrorDetails(error))
if error.can_continue(self._context):
self.assign(error.return_value)
[docs] def assign(self, return_value):
context = self._context
context.output.trace(lambda: 'Return: %s' % prepr(return_value),
write_if_flat=False)
resolver = ReturnValueResolver(self._assignment)
for name, items, value in resolver.resolve(return_value):
if items:
value = self._item_assign(name, items, value, context.variables)
elif not self._extended_assign(name, value, context.variables):
value = self._normal_assign(name, value, context.variables)
context.info(format_assign_message(name, value, items))
def _extended_assign(self, name, value, variables):
if name[0] != '$' or '.' not in name or name in variables:
return False
base, attr = [token.strip() for token in name[2:-1].rsplit('.', 1)]
try:
var = variables.replace_scalar('${%s}' % base)
except VariableError:
return False
if not (self._variable_supports_extended_assign(var) and
self._is_valid_extended_attribute(attr)):
return False
try:
setattr(var, attr, value)
except:
raise VariableError("Setting attribute '%s' to variable '${%s}' failed: %s"
% (attr, base, get_error_message()))
return True
def _variable_supports_extended_assign(self, var):
return not (is_string(var) or is_number(var))
def _is_valid_extended_attribute(self, attr):
return self._valid_extended_attr.match(attr) is not None
def _parse_sequence_index(self, index):
if isinstance(index, (int, slice)):
return index
if not is_string(index):
raise ValueError
if ':' not in index:
return int(index)
if index.count(':') > 2:
raise ValueError
return slice(*[int(i) if i else None for i in index.split(':')])
def _variable_type_supports_item_assign(self, var):
return (hasattr(var, '__setitem__') and callable(var.__setitem__))
def _raise_cannot_set_type(self, value, expected):
value_type = type_name(value)
raise VariableError(f"Expected {expected}-like value, got {value_type}.")
def _validate_item_assign(self, name, value):
if name[0] == '@':
if not is_list_like(value):
self._raise_cannot_set_type(value, 'list')
value = list(value)
if name[0] == '&':
if not is_dict_like(value):
self._raise_cannot_set_type(value, 'dictionary')
value = DotDict(value)
return value
def _item_assign(self, name, items, value, variables):
*nested, item = items
decorated_nested_items = ''.join(f'[{item}]' for item in nested)
var = variables.replace_scalar(f'${name[1:]}{decorated_nested_items}')
if not self._variable_type_supports_item_assign(var):
var_type = type_name(var)
raise VariableError(
f"Variable '{name}{decorated_nested_items}' is {var_type} "
f"and does not support item assignment."
)
selector = variables.replace_scalar(item)
if isinstance(var, MutableSequence):
try:
selector = self._parse_sequence_index(selector)
except ValueError:
pass
try:
value = self._validate_item_assign(name, value)
var[selector] = value
except (IndexError, TypeError, Exception):
var_type = type_name(var)
raise VariableError(
f"Setting value to {var_type} variable "
f"'{name}{decorated_nested_items}' "
f"at index [{item}] failed: {get_error_message()}"
)
return value
def _normal_assign(self, name, value, variables):
variables[name] = value
# Always return the actually assigned value.
return value if name[0] == '$' else variables[name]
[docs]def ReturnValueResolver(assignment):
if not assignment:
return NoReturnValueResolver()
if len(assignment) == 1:
return OneReturnValueResolver(assignment[0])
if any(a[0] == '@' for a in assignment):
return ScalarsAndListReturnValueResolver(assignment)
return ScalarsOnlyReturnValueResolver(assignment)
[docs]class NoReturnValueResolver:
[docs] def resolve(self, return_value):
return []
[docs]class OneReturnValueResolver:
def __init__(self, assignment):
match: VariableMatch = search_variable(assignment)
self._name = match.name
self._items = match.items
[docs] def resolve(self, return_value):
if return_value is None:
identifier = self._name[0]
return_value = {'$': None, '@': [], '&': {}}[identifier]
return [(self._name, self._items, return_value)]
class _MultiReturnValueResolver:
def __init__(self, assignments):
self._names = []
self._items = []
for assigment in assignments:
match: VariableMatch = search_variable(assigment)
self._names.append(match.name)
self._items.append(match.items)
self._min_count = len(assignments)
def resolve(self, return_value):
return_value = self._convert_to_list(return_value)
self._validate(len(return_value))
return self._resolve(return_value)
def _convert_to_list(self, return_value):
if return_value is None:
return [None] * self._min_count
if is_string(return_value):
self._raise_expected_list(return_value)
try:
return list(return_value)
except TypeError:
self._raise_expected_list(return_value)
def _raise_expected_list(self, ret):
self._raise('Expected list-like value, got %s.' % type_name(ret))
def _raise(self, error):
raise VariableError('Cannot set variables: %s' % error)
def _validate(self, return_count):
raise NotImplementedError
def _resolve(self, return_value):
raise NotImplementedError
[docs]class ScalarsOnlyReturnValueResolver(_MultiReturnValueResolver):
def _validate(self, return_count):
if return_count != self._min_count:
self._raise('Expected %d return values, got %d.'
% (self._min_count, return_count))
def _resolve(self, return_value):
return list(zip(self._names, self._items, return_value))
[docs]class ScalarsAndListReturnValueResolver(_MultiReturnValueResolver):
def __init__(self, assignments):
_MultiReturnValueResolver.__init__(self, assignments)
self._min_count -= 1
def _validate(self, return_count):
if return_count < self._min_count:
self._raise('Expected %d or more return values, got %d.'
% (self._min_count, return_count))
def _resolve(self, return_value):
list_index = [a[0][0] for a in self._names].index('@')
list_len = len(return_value) - len(self._names) + 1
elements_before_list = list(zip(
self._names[:list_index],
self._items[:list_index],
return_value[:list_index],
))
elements_after_list = list(zip(
self._names[list_index+1:],
self._items[list_index+1:],
return_value[list_index+list_len:],
))
list_elements = [(
self._names[list_index],
self._items[list_index],
return_value[list_index:list_index+list_len],
)]
return elements_before_list + list_elements + elements_after_list