Rewrite tr-like function calls found in Slicer scripted modules to include the context as first argument

slicer_lupdate_preprocess.py

# SPDX-FileCopyrightText: 2023 Jean-Christophe Fillion-Robin <jcfr@kitware.com>
# SPDX-License-Identifier: BSD-3-Clause

import ast
import argparse
import errno
import os
import sys

import astor


class TrFunctionRewriter(ast.NodeTransformer):

    def __init__(self, input_file):
        self.current_context = os.path.splitext(os.path.basename(input_file))[0]

    """Replace tr to QT_TRANSLATE_NOOP."""
    def visit_Call(self, node):
        self.generic_visit(node)
        # Transform tr-like functions  into 'QT_TRANSLATE_NOOP' """
        if (isinstance(node.func, ast.Name) and \
           (node.func.id in ["_", "tr", "translate"]) and \
           len(node.args) == 1):

            # Insert the context
            updated_args = [ast.Constant(self.current_context)] + node.args

            call = ast.Call(func=ast.Name(id=node.func.id, ctx=ast.Load()),
                            args=updated_args,
                            keywords=[])
            ast.copy_location(call, node)
            # Add lineno & col_offset to the nodes we created
            ast.fix_missing_locations(call)
            return call

        # Return the original node if we don't want to change it.
        return node


def mkdir_p(path):
    """Ensure directory ``path`` exists. If needed, parent directories
    are created.
    Adapted from http://stackoverflow.com/a/600612/1539918
    """
    try:
        os.makedirs(path)
    except OSError as exc:  # Python >2.5
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:  # pragma: no cover
            raise


def main(argv):
    parser = argparse.ArgumentParser(description="slicer_lupdate_preprocess.py")
    parser.add_argument("-i", "--ifile", type=str, help="input file")
    parser.add_argument("-o", "--ofile", type=str, help="output file")
    args = parser.parse_args()
    if not args.ifile or not args.ofile:
        parser.print_help()
        sys.exit(2)

    input_file = args.ifile
    output_file = args.ofile

    with open(input_file, "r") as source:
        tree = ast.parse(source.read())

    tree_new = TrFunctionRewriter(input_file=input_file).visit(tree)  
    all_lines = astor.to_source(tree_new)

    # if needed, create output directory
    output_dir = os.path.dirname(output_file)
    if output_dir:
        mkdir_p(output_dir)

    with open(output_file, "w") as destination:
        for line in all_lines:
            destination.write(line)

    print(f"output_file [{output_file}]")

if __name__ == "__main__":
    main(sys.argv[1:])

This script was created in the context of pull-request Slicer#6917 and is based of prior work done in the context of pull-request Slicer#6050 from 2021.

Input: MyModule.py

from slicer.translation import tr as _


class MyModuleWidget:

    def someFunction(self):
        myMessage = _("Press any key to continue")
        myMessage = _("Press {key} to continue").format(key=key)

Usage

!pip install astor

python slicer_lupdate_preprocess.py -i MyModule.py -o MyModule.lupdate.py

diff MyModule.py MyModule.lupdate.py
7,8c7,8
<         myMessage = _("Press any key to continue")
<         myMessage = _("Press {key} to continue").format(key=key)
---
>         myMessage = _('MyModule', 'Press any key to continue')
>         myMessage = _('MyModule', 'Press {key} to continue').format(key=key)

!pip install pyside6

$ pyside6-lupdate MyModule.lupdate.py -ts MyModule.ts -tr-function-alias translate+=tr,translate+=_
Updating 'MyModule.ts'...
    Found 2 source text(s) (2 new and 0 already existing)

$ cat MyModule.ts
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE TS>
<TS version="2.1">
<context>
    <name>MyModule</name>
    <message>
        <location filename="MyModule.tr.py" line="8"/>
        <source>Press any key to continue</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="MyModule.tr.py" line="8"/>
        <source>Press {key} to continue</source>
        <translation type="unfinished"></translation>
    </message>
</context>
</TS>