Files
paperless-ngx/src/documents/plugins/date_parsing/base.py

125 lines
3.3 KiB
Python

import datetime
import logging
from abc import ABC
from abc import abstractmethod
from collections.abc import Iterator
from dataclasses import dataclass
from types import TracebackType
try:
from typing import Self
except ImportError:
from typing_extensions import Self
import dateparser
logger = logging.getLogger(__name__)
@dataclass(frozen=True, slots=True)
class DateParserConfig:
"""
Configuration for a DateParser instance.
This object is created by the factory and passed to the
parser's constructor, decoupling the parser from settings.
"""
languages: list[str]
timezone_str: str
ignore_dates: set[datetime.date]
# A "now" timestamp for filtering future dates.
# Passed in by the factory.
reference_time: datetime.datetime
# Settings for the default RegexDateParser
# Other plugins should use or consider these, but it is not required
filename_date_order: str | None
content_date_order: str
class DateParserPluginBase(ABC):
"""
Abstract base class for date parsing strategies.
Instances are configured via a DateParserConfig object.
"""
def __init__(self, config: DateParserConfig):
"""
Initializes the parser with its configuration.
"""
self.config = config
def __enter__(self) -> Self:
"""
Enter the runtime context related to this object.
Subclasses can override this to acquire resources (connections, handles).
"""
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_val: BaseException | None,
exc_tb: TracebackType | None,
) -> None:
"""
Exit the runtime context related to this object.
Subclasses can override this to release resources.
"""
# Default implementation does nothing.
# Returning None implies exceptions are propagated.
def _parse_string(
self,
date_string: str,
date_order: str,
) -> datetime.datetime | None:
"""
Helper method to parse a single date string using dateparser.
Uses configuration from `self.config`.
"""
try:
return dateparser.parse(
date_string,
settings={
"DATE_ORDER": date_order,
"PREFER_DAY_OF_MONTH": "first",
"RETURN_AS_TIMEZONE_AWARE": True,
"TIMEZONE": self.config.timezone_str,
},
locales=self.config.languages,
)
except Exception as e:
logger.error(f"Error while parsing date string '{date_string}': {e}")
return None
def _filter_date(
self,
date: datetime.datetime | None,
) -> datetime.datetime | None:
"""
Helper method to validate a parsed datetime object.
Uses configuration from `self.config`.
"""
if (
date is not None
and date.year > 1900
and date <= self.config.reference_time
and date.date() not in self.config.ignore_dates
):
return date
return None
@abstractmethod
def parse(self, filename: str, content: str) -> Iterator[datetime.datetime]:
"""
Parses a document's filename and content, yielding valid datetime objects.
"""