runtime/__init__.py
author Edouard Tisserant
Tue, 25 Aug 2020 14:32:39 +0200
branchsvghmi
changeset 3036 4930455428df
parent 2586 b89484560a97
child 3750 f62625418bff
permissions -rw-r--r--
SVGHMI: JsonTable now use intermediate variables again to address JSON data without duplicating code or referencing. Using intermediate variables also alows to check for availability of data and stop evaluating early if data is missing. Finally added complete roundtrip example to illustrate use of JSonTable to display "alarms" collected in python from changes on PLC boolean variables.
#!/usr/bin/env python
# -*- coding: utf-8 -*-

from __future__ import absolute_import
from __future__ import print_function
import traceback
import sys

from runtime.Worker import worker
MainWorker = worker()

_PLCObjectSingleton = None


def GetPLCObjectSingleton():
    assert _PLCObjectSingleton is not None
    return _PLCObjectSingleton


def LogMessageAndException(msg, exp=None):
    if exp is None:
        exp = sys.exc_info()
    if _PLCObjectSingleton is not None:
        _PLCObjectSingleton.LogMessage(0, msg + '\n'.join(traceback.format_exception(*exp)))
    print(msg)
    traceback.print_exception(*exp)


def CreatePLCObjectSingleton(*args, **kwargs):
    global _PLCObjectSingleton
    from runtime.PLCObject import PLCObject  # noqa # pylint: disable=wrong-import-position
    _PLCObjectSingleton = PLCObject(*args, **kwargs)


def default_evaluator(tocall, *args, **kwargs):
    try:
        res = (tocall(*args, **kwargs), None)
    except Exception:
        res = (None, sys.exc_info())
    return res