hojichar.utils.load_compose

  1import importlib.util
  2import logging
  3import sys
  4from os import PathLike
  5from pathlib import Path
  6from types import ModuleType
  7from typing import Any, Callable, Optional, Union
  8
  9import hojichar
 10
 11logger = logging.getLogger(__name__)
 12
 13
 14def _load_module(path: Union[str, PathLike]) -> ModuleType:
 15    # HACK type hint `os.PathLike[str]` is not allowed in Python 3.8 or older.
 16    # So I write Union[str, PathLike]
 17    path_obj = Path(path)
 18    module_name = path_obj.stem
 19    spec = importlib.util.spec_from_file_location(module_name, path_obj)
 20    if spec and spec.loader:
 21        module = importlib.util.module_from_spec(spec)
 22        sys.modules[module_name] = module
 23        spec.loader.exec_module(module)
 24    return module
 25
 26
 27def load_filter_from_file(profile_path: Union[str, PathLike]) -> hojichar.Compose:
 28    """
 29    Loading a profile which has `FILTER` variable.
 30    Given path is added to sys.path automaticaly.
 31
 32    Args:
 33        profile_path (str): Path to a Python file that implements custom filter
 34        hojichar.Compose must be defined as FILTER variable in the file.
 35
 36    Raises:
 37        NotImplementedError:
 38
 39    Returns:
 40        hojichar.Compose:
 41    """
 42    sys.path.append(str(Path(profile_path).parent))
 43    module = _load_module(profile_path)
 44    if hasattr(module, "FILTER"):
 45        filter = getattr(module, "FILTER")
 46        if not isinstance(filter, hojichar.Compose):
 47            raise TypeError("FILTER must be hojichar.Compose object.")
 48        return filter
 49    else:
 50        raise NotImplementedError("FILTER is not defined in the profile.")
 51
 52
 53def load_factory_from_file(
 54    profile_path: Union[str, PathLike]
 55) -> Callable[[Optional[Any]], hojichar.Compose]:
 56    """
 57    Loading a function by a profile which has `FACTORY` variable.
 58    Given path is added to sys.path automaticaly.
 59
 60    Args:
 61        profile_path (PathLike): Path to a Python file that implements custom filter
 62
 63    Raises:
 64        NotImplementedError:
 65
 66    Returns:
 67        Callable[[Optional[Any]], hojichar.Compose]:
 68            An alias of the function which returns Compose.
 69    """
 70    sys.path.append(str(Path(profile_path).parent))
 71    module = _load_module(profile_path)
 72    if hasattr(module, "FACTORY"):
 73        factory: Callable[[Optional[Any]], hojichar.Compose] = getattr(module, "FACTORY")
 74        return factory
 75    else:
 76        raise NotImplementedError("FACTORY is not defined in the profile")
 77
 78
 79def load_parametrized_filter_from_file(
 80    profile_path: Union[str, PathLike], *factory_args: str
 81) -> hojichar.Compose:
 82    factory = load_factory_from_file(profile_path)
 83    filter = factory(*factory_args)
 84    return filter
 85
 86
 87def load_compose(profile_path: Union[str, PathLike], *factroy_args: str) -> hojichar.Compose:
 88    """
 89    Loading a Compose file from profile. Loading a Compose file from the profile.
 90    Both `FILTER` and `FACTORY` pattern of the profile is loaded.
 91
 92    Args:
 93        profile_path (PathLike):
 94
 95    Returns:
 96        hojichar.Compose:
 97    """
 98    try:
 99        filter = load_filter_from_file(profile_path)
100        _check_args_num_mismatch(len(factroy_args))
101        return filter
102    except NotImplementedError:
103        return load_parametrized_filter_from_file(profile_path, *factroy_args)
104
105
106def _check_args_num_mismatch(num_args: int) -> None:
107    if num_args > 0:
108        logger.warning(f"Warning: {num_args} arguments are ignored.")