Source code for bokeh.application.handlers.code_runner
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# Copyright (c) 2012 - 2022, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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''' Provide a utility class ``CodeRunner`` for use by handlers that execute
Python source code.
'''
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# Boilerplate
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from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
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# Imports
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# Standard library imports
import os
import sys
import traceback
from os.path import basename
from types import CodeType, ModuleType
from typing import Callable
# Bokeh imports
from ...core.types import PathLike
from ...util.serialization import make_globally_unique_id
from .handler import handle_exception
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# Globals and constants
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__all__ = (
'CodeRunner',
)
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# General API
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# Dev API
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[docs]class CodeRunner:
''' Compile and run Python source code.
.. autoclasstoc::
'''
_code: CodeType | None
_doc: str | None
_permanent_error: str | None
_permanent_error_detail: str | None
_path: PathLike
_source: str
_argv: list[str]
_package: ModuleType | None
ran: bool
_failed: bool
_error: str | None
_error_detail: str | None
[docs] def __init__(self, source: str, path: PathLike, argv: list[str], package: ModuleType | None = None) -> None:
'''
Args:
source (str) :
A string containing Python source code to execute
path (str) :
A filename to use in any debugging or error output
argv (list[str]) :
A list of string arguments to make available as ``sys.argv``
when the code executes
package (bool) :
An optional package module to configure
Raises:
ValueError, if package is specified for an __init__.py
'''
if package and basename(path) == "__init__.py":
raise ValueError("__init__.py cannot have package specified")
self._permanent_error = None
self._permanent_error_detail = None
self.reset_run_errors()
import ast
self._code = None
try:
nodes = ast.parse(source, os.fspath(path))
self._code = compile(nodes, filename=path, mode='exec', dont_inherit=True)
# use a zip to associate code names with values, to then find the contents of the docstring
d = dict(zip(self._code.co_names, self._code.co_consts))
self._doc = d.get('__doc__', None)
except SyntaxError as e:
self._code = None
filename = os.path.basename(e.filename) if e.filename is not None else "???"
self._permanent_error = f"Invalid syntax in {filename!r} on line {e.lineno or '???'}:\n{e.text or '???'}"
self._permanent_error_detail = traceback.format_exc()
self._path = path
self._source = source
self._argv = argv
self._package = package
self.ran = False
# Properties --------------------------------------------------------------
@property
def doc(self) -> str | None:
''' Contents of docstring, if code contains one.
'''
return self._doc
@property
def error(self) -> str | None:
''' If code execution fails, may contain a related error message.
'''
return self._error if self._permanent_error is None else self._permanent_error
@property
def error_detail(self) -> str | None:
''' If code execution fails, may contain a traceback or other details.
'''
return self._error_detail if self._permanent_error_detail is None else self._permanent_error_detail
@property
def failed(self) -> bool:
''' ``True`` if code execution failed
'''
return self._failed or self._code is None
@property
def path(self) -> PathLike:
''' The path that new modules will be configured with.
'''
return self._path
@property
def source(self) -> str:
''' The configured source code that will be executed when ``run`` is
called.
'''
return self._source
# Public methods ----------------------------------------------------------
[docs] def new_module(self) -> ModuleType | None:
''' Make a fresh module to run in.
Returns:
Module
'''
self.reset_run_errors()
if self._code is None:
return None
module_name = 'bokeh_app_' + make_globally_unique_id().replace('-', '')
module = ModuleType(module_name)
module.__dict__['__file__'] = os.path.abspath(self._path)
if self._package:
module.__package__ = self._package.__name__
module.__path__ = [os.path.dirname(self._path)]
if basename(self.path) == "__init__.py":
module.__package__ = module_name
module.__path__ = [os.path.dirname(self._path)]
return module
[docs] def reset_run_errors(self) -> None:
''' Clears any transient error conditions from a previous run.
Returns
None
'''
self._failed = False
self._error = None
self._error_detail = None
[docs] def run(self, module: ModuleType, post_check: Callable[[], None] | None = None) -> None:
''' Execute the configured source code in a module and run any post
checks.
Args:
module (Module) :
A module to execute the configured code in.
post_check (callable, optional) :
A function that raises an exception if expected post-conditions
are not met after code execution.
'''
# Simulate the sys.path behaviour described here:
#
# https://docs.python.org/2/library/sys.html#sys.path
_cwd = os.getcwd()
_sys_path = list(sys.path)
_sys_argv = list(sys.argv)
sys.path.insert(0, os.path.dirname(self._path))
sys.argv = [os.path.basename(self._path)] + self._argv
# XXX: self._code shouldn't be None at this point but types don't reflect this
assert self._code is not None
try:
exec(self._code, module.__dict__)
if post_check:
post_check()
except Exception as e:
handle_exception(self, e)
finally:
# undo sys.path, CWD fixups
os.chdir(_cwd)
sys.path = _sys_path
sys.argv = _sys_argv
self.ran = True
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# Private API
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# Code
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