"""
Base finders
"""
import functools
import logging
from collections import namedtuple
from pathlib import Path
from moderngl_window.conf import settings
from moderngl_window.exceptions import ImproperlyConfigured
from moderngl_window.utils.module_loading import import_string
FinderEntry = namedtuple('FinderEntry', ['path', 'abspath', 'exists'])
logger = logging.getLogger(__name__)
[docs]class BaseFilesystemFinder:
"""Base class for searching filesystem directories"""
settings_attr = None
"""str: Name of the attribute in :py:class:`~moderngl_window.conf.Settings`
containing a list of paths the finder should seach in.
"""
[docs] def __init__(self):
"""Initialize finder class by looking up the paths referenced in ``settings_attr``.
"""
if not hasattr(settings, self.settings_attr):
raise ImproperlyConfigured(
"Settings doesn't define {}. "
"This is required when using a FileSystemFinder.".format(self.settings_attr)
)
self.paths = getattr(settings, self.settings_attr)
[docs] def find(self, path: Path) -> Path:
"""Finds a file in the configured paths returning its absolute path.
Args:
path (pathlib.Path): The path to find
Returns:
The absolute path to the file or None if not found
"""
# Update paths from settings to make them editable runtime
if getattr(self, 'settings_attr', None):
self.paths = getattr(settings, self.settings_attr)
if not isinstance(path, Path):
raise ValueError("FilesystemFinders only take Path instances, not {}".format(type(path)))
logger.debug("find %s", path)
# Ignore absolute paths so other finder types can pick them up.
if path.is_absolute():
logger.debug("Ignoring absolute path: %s", path)
return None
logger.debug("paths: %s", self.paths)
for search_path in self.paths:
search_path = Path(search_path)
# Keep ensuring all search paths are absolute
if not search_path.is_absolute():
raise ImproperlyConfigured("Search search path '{}' is not an absolute path")
abspath = search_path / path
logger.debug("abspath %s", abspath)
if abspath.exists():
logger.debug("found %s", abspath)
return abspath
return None
@functools.lru_cache(maxsize=None)
def get_finder(import_path: str):
"""
Get a finder class from an import path.
This function uses an lru cache.
Args:
import_path: string representing an import path
Return:
An instance of the finder
Raises:
ImproperlyConfigured is the finder is not found
"""
Finder = import_string(import_path)
if not issubclass(Finder, BaseFilesystemFinder):
raise ImproperlyConfigured('Finder {} is not a subclass of .finders.FileSystemFinder'.format(import_path))
return Finder()