casa6

import os

import functools

import inspect

from xml.dom import minidom

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import casatasks

​

# constants for generating converter method

__FUNCTION = 'override_args'

__ARGS = '_a'

__ARGS_DICT = '_d'

__ARGS_SUPPLIED = '_s'

__LOGLEVEL_IN_FUNCTION = 'INFO'

​

__DEBUG = False

if __DEBUG:

    from pprint import pprint

​

​

def xml_constraints_injector(func):

    """Decorator which loads constraints from a casatask XML file and apply them to the arguments of the decorated casatask.

​

    This method is designed as decorator for task methods. It executes as below:

    1. converts a constraints element of a CASA task XML to a Python code.

    2. evaluates the code, then a Python function is generated.

    3. executes the function and overrides task arguments to values defined by constraints tag.

​

    ex)

    a constraints tag of a CASA task XML:

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    <constraints>

            <when param="timebin">

                <notequals type="string" value="">

                        <default param="timespan"><value type="string"/></default>

                </notequals>

            </when>

            <when param="fitmode">

                <equals value="list">

                        <default param="nfit"><value type="vector"><value>0</value></value></default>

                </equals>

                <equals value="auto">

                        <default param="thresh"><value>5.0</value></default>

                        <default param="avg_limit"><value>4</value></default>

                        <default param="minwidth"><value>4</value></default>

                        <default param="edge"><value type="vector"><value>0</value></value></default>

                </equals>

                <equals value="interact">

                        <default param="nfit"><value type="vector"><value>0</value></value></default>

                </equals>

            </when>

    </constraints>

​

    generated Python function code from the above XML:

​

    def override_args(_a, _d, _s):  # _a: position args based on *args

                                    # _d: dict[key: position name, val: corresponding position index of a key]

                                    #     to use to get a position index of args by position name

                                    # _s: boolean array, it is the same length as the position args,

                                    #     and the positions of user-supplied arguments are set to True

        if _d.get('timebin') is not None and _a[_d['timebin']] != '':

            if _d.get('timespan') is not None and _s[_d['timespan']] is False and _a[_d['timespan']] == "":

                _a[_d['timespan']] = ''

                casatasks.casalog.post("overrode argument: timespan -> ''", "INFO")