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Direktori : /proc/self/root/opt/alt/python37/lib64/python3.7/site-packages/sqlalchemy/event/ |
Current File : //proc/self/root/opt/alt/python37/lib64/python3.7/site-packages/sqlalchemy/event/legacy.py |
# event/legacy.py # Copyright (C) 2005-2019 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php """Routines to handle adaption of legacy call signatures, generation of deprecation notes and docstrings. """ from .. import util def _legacy_signature(since, argnames, converter=None): def leg(fn): if not hasattr(fn, "_legacy_signatures"): fn._legacy_signatures = [] fn._legacy_signatures.append((since, argnames, converter)) return fn return leg def _wrap_fn_for_legacy(dispatch_collection, fn, argspec): for since, argnames, conv in dispatch_collection.legacy_signatures: if argnames[-1] == "**kw": has_kw = True argnames = argnames[0:-1] else: has_kw = False if len(argnames) == len(argspec.args) and has_kw is bool( argspec.varkw ): if conv: assert not has_kw def wrap_leg(*args): return fn(*conv(*args)) else: def wrap_leg(*args, **kw): argdict = dict(zip(dispatch_collection.arg_names, args)) args = [argdict[name] for name in argnames] if has_kw: return fn(*args, **kw) else: return fn(*args) return wrap_leg else: return fn def _indent(text, indent): return "\n".join(indent + line for line in text.split("\n")) def _standard_listen_example(dispatch_collection, sample_target, fn): example_kw_arg = _indent( "\n".join( "%(arg)s = kw['%(arg)s']" % {"arg": arg} for arg in dispatch_collection.arg_names[0:2] ), " ", ) if dispatch_collection.legacy_signatures: current_since = max( since for since, args, conv in dispatch_collection.legacy_signatures ) else: current_since = None text = ( "from sqlalchemy import event\n\n" "# standard decorator style%(current_since)s\n" "@event.listens_for(%(sample_target)s, '%(event_name)s')\n" "def receive_%(event_name)s(" "%(named_event_arguments)s%(has_kw_arguments)s):\n" " \"listen for the '%(event_name)s' event\"\n" "\n # ... (event handling logic) ...\n" ) if len(dispatch_collection.arg_names) > 3: text += ( "\n# named argument style (new in 0.9)\n" "@event.listens_for(" "%(sample_target)s, '%(event_name)s', named=True)\n" "def receive_%(event_name)s(**kw):\n" " \"listen for the '%(event_name)s' event\"\n" "%(example_kw_arg)s\n" "\n # ... (event handling logic) ...\n" ) text %= { "current_since": " (arguments as of %s)" % current_since if current_since else "", "event_name": fn.__name__, "has_kw_arguments": ", **kw" if dispatch_collection.has_kw else "", "named_event_arguments": ", ".join(dispatch_collection.arg_names), "example_kw_arg": example_kw_arg, "sample_target": sample_target, } return text def _legacy_listen_examples(dispatch_collection, sample_target, fn): text = "" for since, args, conv in dispatch_collection.legacy_signatures: text += ( "\n# DEPRECATED calling style (pre-%(since)s, " "will be removed in a future release)\n" "@event.listens_for(%(sample_target)s, '%(event_name)s')\n" "def receive_%(event_name)s(" "%(named_event_arguments)s%(has_kw_arguments)s):\n" " \"listen for the '%(event_name)s' event\"\n" "\n # ... (event handling logic) ...\n" % { "since": since, "event_name": fn.__name__, "has_kw_arguments": " **kw" if dispatch_collection.has_kw else "", "named_event_arguments": ", ".join(args), "sample_target": sample_target, } ) return text def _version_signature_changes(parent_dispatch_cls, dispatch_collection): since, args, conv = dispatch_collection.legacy_signatures[0] return ( "\n.. deprecated:: %(since)s\n" " The :class:`.%(clsname)s.%(event_name)s` event now accepts the \n" " arguments ``%(named_event_arguments)s%(has_kw_arguments)s``.\n" " Support for listener functions which accept the previous \n" ' argument signature(s) listed above as "deprecated" will be \n' " removed in a future release." % { "since": since, "clsname": parent_dispatch_cls.__name__, "event_name": dispatch_collection.name, "named_event_arguments": ", ".join(dispatch_collection.arg_names), "has_kw_arguments": ", **kw" if dispatch_collection.has_kw else "", } ) def _augment_fn_docs(dispatch_collection, parent_dispatch_cls, fn): header = ( ".. container:: event_signatures\n\n" " Example argument forms::\n" "\n" ) sample_target = getattr(parent_dispatch_cls, "_target_class_doc", "obj") text = header + _indent( _standard_listen_example(dispatch_collection, sample_target, fn), " " * 8, ) if dispatch_collection.legacy_signatures: text += _indent( _legacy_listen_examples(dispatch_collection, sample_target, fn), " " * 8, ) text += _version_signature_changes( parent_dispatch_cls, dispatch_collection ) return util.inject_docstring_text(fn.__doc__, text, 1)