42 from cubicweb.cwconfig import CubicWebConfiguration

    43 

    44 def class_regid(cls):

    45     """returns a unique identifier for an appobject class"""

    46     if 'id' in cls.__dict__:

    47         warn('[3.6] %s.%s: id is deprecated, use __regid__'

    48              % (cls.__module__, cls.__name__), DeprecationWarning)

    49         cls.__regid__ = cls.id

    50     if hasattr(cls, 'id') and not isinstance(cls.id, property):

    51         return cls.id

    52     return cls.__regid__

    53 

    54 # helpers for debugging selectors

    55 TRACED_OIDS = None

    56 

    57 def _trace_selector(cls, selector, args, ret):

    58     # /!\ lltrace decorates pure function or __call__ method, this

    59     #     means argument order may be different

    60     if isinstance(cls, Selector):

    61         selname = str(cls)

    62         vobj = args[0]

    63     else:

    64         selname = selector.__name__

    65         vobj = cls

    66     if TRACED_OIDS == 'all' or class_regid(vobj) in TRACED_OIDS:

    67         #SELECTOR_LOGGER.warning('selector %s returned %s for %s', selname, ret, cls)

    68         print '%s -> %s for %s(%s)' % (selname, ret, vobj, vobj.__regid__)

    69 

    70 def lltrace(selector):

    71     """use this decorator on your selectors so the becomes traceable with

    72     :class:`traced_selection`

    73     """

    74     # don't wrap selectors if not in development mode

    75     if CubicWebConfiguration.mode == 'system': # XXX config.debug

    76         return selector

    77     def traced(cls, *args, **kwargs):

    78         ret = selector(cls, *args, **kwargs)

    79         if TRACED_OIDS is not None:

    80             _trace_selector(cls, selector, args, ret)

    81         return ret

    82     traced.__name__ = selector.__name__

    83     traced.__doc__ = selector.__doc__

    84     return traced

    85 

    86 class traced_selection(object):

    87     """

    88     Typical usage is :

    89 

    90     .. sourcecode:: python

    91 

    92         >>> from cubicweb.selectors import traced_selection

    93         >>> with traced_selection():

    94         ...     # some code in which you want to debug selectors

    95         ...     # for all objects

    96 

    97     Don't forget the 'from __future__ import with_statement' at the module top-level

    98     if you're using python prior to 2.6.

    99 

   100     This will yield lines like this in the logs::

   101 

   102         selector one_line_rset returned 0 for <class 'cubicweb.web.views.basecomponents.WFHistoryVComponent'>

   103 

   104     You can also give to :class:`traced_selection` the identifiers of objects on

   105     which you want to debug selection ('oid1' and 'oid2' in the example above).

   106 

   107     .. sourcecode:: python

   108 

   109         >>> with traced_selection( ('regid1', 'regid2') ):

   110         ...     # some code in which you want to debug selectors

   111         ...     # for objects with __regid__ 'regid1' and 'regid2'

   112 

   113     A potentially usefull point to set up such a tracing function is

   114     the `cubicweb.vregistry.Registry.select` method body.

   115     """

   116 

   117     def __init__(self, traced='all'):

   118         self.traced = traced

   119 

   120     def __enter__(self):

   121         global TRACED_OIDS

   122         TRACED_OIDS = self.traced

   123 

   124     def __exit__(self, exctype, exc, traceback):

   125         global TRACED_OIDS

   126         TRACED_OIDS = None

   127         return traceback is None

   264     @lltrace

   277     @lltrace

   290     @lltrace