Source code for sphinx.events

"""
    sphinx.events
    ~~~~~~~~~~~~~

    Sphinx core events.

    Gracefully adapted from the TextPress system by Armin.

    :copyright: Copyright 2007-2021 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

from collections import defaultdict
from operator import attrgetter
from typing import TYPE_CHECKING, Any, Callable, Dict, List, NamedTuple, Tuple, Type

from sphinx.errors import ExtensionError, SphinxError
from sphinx.locale import __
from sphinx.util import logging
from sphinx.util.inspect import safe_getattr

if TYPE_CHECKING:
    from sphinx.application import Sphinx


logger = logging.getLogger(__name__)


class EventListener(NamedTuple):
    id: int
    handler: Callable
    priority: int


# List of all known core events. Maps name to arguments description.
core_events = {
    'builder-inited': '',
    'config-inited': 'config',
    'env-get-outdated': 'env, added, changed, removed',
    'env-get-updated': 'env',
    'env-purge-doc': 'env, docname',
    'env-before-read-docs': 'env, docnames',
    'env-check-consistency': 'env',
    'source-read': 'docname, source text',
    'doctree-read': 'the doctree before being pickled',
    'env-merge-info': 'env, read docnames, other env instance',
    'missing-reference': 'env, node, contnode',
    'warn-missing-reference': 'domain, node',
    'doctree-resolved': 'doctree, docname',
    'env-updated': 'env',
    'build-finished': 'exception',
}


[docs]class EventManager: """Event manager for Sphinx.""" def __init__(self, app: "Sphinx") -> None: self.app = app self.events = core_events.copy() self.listeners = defaultdict(list) # type: Dict[str, List[EventListener]] self.next_listener_id = 0
[docs] def add(self, name: str) -> None: """Register a custom Sphinx event.""" if name in self.events: raise ExtensionError(__('Event %r already present') % name) self.events[name] = ''
[docs] def connect(self, name: str, callback: Callable, priority: int) -> int: """Connect a handler to specific event.""" if name not in self.events: raise ExtensionError(__('Unknown event name: %s') % name) listener_id = self.next_listener_id self.next_listener_id += 1 self.listeners[name].append(EventListener(listener_id, callback, priority)) return listener_id
[docs] def disconnect(self, listener_id: int) -> None: """Disconnect a handler.""" for listeners in self.listeners.values(): for listener in listeners[:]: if listener.id == listener_id: listeners.remove(listener)
[docs] def emit(self, name: str, *args: Any, allowed_exceptions: Tuple[Type[Exception], ...] = ()) -> List: """Emit a Sphinx event.""" try: logger.debug('[app] emitting event: %r%s', name, repr(args)[:100]) except Exception: # not every object likes to be repr()'d (think # random stuff coming via autodoc) pass results = [] listeners = sorted(self.listeners[name], key=attrgetter("priority")) for listener in listeners: try: results.append(listener.handler(self.app, *args)) except allowed_exceptions: # pass through the errors specified as *allowed_exceptions* raise except SphinxError: raise except Exception as exc: modname = safe_getattr(listener.handler, '__module__', None) raise ExtensionError(__("Handler %r for event %r threw an exception") % (listener.handler, name), exc, modname=modname) from exc return results
[docs] def emit_firstresult(self, name: str, *args: Any, allowed_exceptions: Tuple[Type[Exception], ...] = ()) -> Any: """Emit a Sphinx event and returns first result. This returns the result of the first handler that doesn't return ``None``. """ for result in self.emit(name, *args, allowed_exceptions=allowed_exceptions): if result is not None: return result return None