def setBehaviour(self, list_of_pmd):
"""
Set the functionalities handled by the plugin manager by
giving a list of ``PluginManager`` decorators.
This function shouldn't be called several time in a same
process, but if it is only the first call will have an effect.
It also has an effect only if called before the initialisation
of the singleton.
In cases where the function is indeed going to change anything
the ``True`` value is return, in all other cases, the ``False``
value is returned.
"""
if self.__decoration_chain is None and self.__instance is None:
log.debug(
"Setting up a specific behaviour for the PluginManagerSingleton"
)
self.__decoration_chain = list_of_pmd
return True
else:
log.debug(
"Useless call to setBehaviour: the singleton is already instanciated of already has a behaviour."
)
return False
def removeAnalyzers(self, name):
"""
Removes analyzers of a given name.
"""
analyzersListCopy = self._analyzers[:]
foundAndRemoved = False
for obj in analyzersListCopy:
if obj.name == name:
self._analyzers.remove(obj)
foundAndRemoved = True
if not foundAndRemoved:
log.debug("'%s' is not a known strategy name: can't remove it." % name)
def activatePluginByName(self, name, category="Default"):
"""
Activate a plugin corresponding to a given category + name.
"""
pta_item = self.getPluginByName(name, category)
if pta_item is not None:
plugin_to_activate = pta_item.plugin_object
if plugin_to_activate is not None:
log.debug("Activating plugin: %s.%s" % (category, name))
plugin_to_activate.activate()
return plugin_to_activate
return None
def getPluginNameAndModuleFromStream(self,
infoFileObject,
candidate_infofile=None):
"""
Extract the name and module of a plugin from the
content of the info file that describes it and which
is stored in ``infoFileObject``.
.. note:: Prefer using ``_extractCorePluginInfo``
instead, whenever possible...
.. warning:: ``infoFileObject`` must be a file-like object:
either an opened file for instance or a string
buffer wrapped in a StringIO instance as another
example.
.. note:: ``candidate_infofile`` must be provided
whenever possible to get better error messages.
Return a 3-uple with the name of the plugin, its
module and the config_parser used to gather the core
data *in a tuple*, if the required info could be
localised, else return ``(None,None,None)``.
.. note:: This is supposed to be used internally by subclasses
and decorators.
"""
# parse the information buffer to get info about the plugin
config_parser = ConfigParser()
try:
if is_py2:
config_parser.readfp(infoFileObject)
else:
config_parser.read_file(infoFileObject)
except Exception as e:
log.debug(
"Could not parse the plugin file '%s' (exception raised was '%s')"
% (candidate_infofile, e))
return (None, None, None)
# check if the basic info is available
if not config_parser.has_section("Core"):
log.debug("Plugin info file has no 'Core' section (in '%s')" %
candidate_infofile)
return (None, None, None)
if not config_parser.has_option(
"Core", "Name") or not config_parser.has_option(
"Core", "Module"):
log.debug(
"Plugin info file has no 'Name' or 'Module' section (in '%s')"
% candidate_infofile)
return (None, None, None)
# check that the given name is valid
name = config_parser.get("Core", "Name")
name = name.strip()
if PLUGIN_NAME_FORBIDEN_STRING in name:
log.debug("Plugin name contains forbiden character: %s (in '%s')" %
(PLUGIN_NAME_FORBIDEN_STRING, candidate_infofile))
return (None, None, None)
return (name, config_parser.get("Core", "Module"), config_parser)
def deactivatePluginByName(self, name, category="Default"):
"""
Desactivate a plugin corresponding to a given category + name.
"""
if category in self.category_mapping:
plugin_to_deactivate = None
for item in self.category_mapping[category]:
if item.name == name:
plugin_to_deactivate = item.plugin_object
break
if plugin_to_deactivate is not None:
log.debug("Deactivating plugin: %s.%s" % (category, name))
plugin_to_deactivate.deactivate()
return plugin_to_deactivate
return None
def __init__(self, decorated_object=None,
# The following args will only be used if we need to
# create a default PluginManager
categories_filter=None,
directories_list=None,
plugin_info_ext="yapsy-plugin"):
if directories_list is None:
directories_list = [os.path.dirname(__file__)]
if categories_filter is None:
categories_filter = {"Default": IPlugin}
if decorated_object is None:
log.debug("Creating a default PluginManager instance to be decorated.")
from yapsy.PluginManager import PluginManager
decorated_object = PluginManager(categories_filter,
directories_list,
plugin_info_ext)
self._component = decorated_object
def get(self):
"""
Actually create an instance
"""
if self.__instance is None:
if self.__decoration_chain is not None:
# Get the object to be decorated
# print self.__decoration_chain
pm = self.__decoration_chain[0]()
for cls_item in self.__decoration_chain[1:]:
# print cls_item
pm = cls_item(decorated_manager=pm)
# Decorate the whole object
self.__instance = pm
else:
# initialise the 'inner' PluginManagerDecorator
self.__instance = PluginManager()
log.debug("PluginManagerSingleton initialised")
return self.__instance
def locatePlugins(self):
"""
Walk through the plugins' places and look for plugins.
Return the candidates and number of plugins found.
"""
# print "%s.locatePlugins" % self.__class__
_candidates = []
_discovered = {}
for directory in map(os.path.abspath, self.plugins_places):
# first of all, is it a directory :)
if not os.path.isdir(directory):
log.debug("%s skips %s (not a directory)" % (self.__class__.__name__, directory))
continue
if self.recursive:
debug_txt_mode = "recursively"
walk_iter = os.walk(directory, followlinks=True)
else:
debug_txt_mode = "non-recursively"
walk_iter = [(directory,[],os.listdir(directory))]
# iteratively walks through the directory
log.debug("%s walks (%s) into directory: %s" % (self.__class__.__name__, debug_txt_mode, directory))
for item in walk_iter:
dirpath = item[0]
for filename in item[2]:
# print("testing candidate file %s" % filename)
for analyzer in self._analyzers:
# print("... with analyzer %s" % analyzer.name)
# eliminate the obvious non plugin files
if not analyzer.isValidPlugin(filename):
log.debug("%s is not a valid plugin for strategy %s" % (filename, analyzer.name))
continue
candidate_infofile = os.path.join(dirpath, filename)
if candidate_infofile in _discovered:
log.debug("%s (with strategy %s) rejected because already discovered" % (candidate_infofile, analyzer.name))
continue
log.debug("%s found a candidate:\n %s" % (self.__class__.__name__, candidate_infofile))
# print candidate_infofile
plugin_info = self._getInfoForPluginFromAnalyzer(analyzer, dirpath, filename)
if plugin_info is None:
log.debug("Plugin candidate '%s' rejected by strategy '%s'" % (candidate_infofile, analyzer.name))
break # we consider this was the good strategy to use for: it failed -> not a plugin -> don't try another strategy
# now determine the path of the file to execute,
# depending on wether the path indicated is a
# directory or a file
# print plugin_info.path
# Remember all the files belonging to a discovered
# plugin, so that strategies (if several in use) won't
# collide
if os.path.isdir(plugin_info.path):
candidate_filepath = os.path.join(plugin_info.path, "__init__")
# it is a package, adds all the files concerned
for _file in os.listdir(plugin_info.path):
if _file.endswith(".py"):
self._discovered_plugins[os.path.join(plugin_info.path, _file)] = candidate_filepath
_discovered[os.path.join(plugin_info.path, _file)] = candidate_filepath
elif (plugin_info.path.endswith(".py") and os.path.isfile(plugin_info.path)) or os.path.isfile(plugin_info.path+".py"):
candidate_filepath = plugin_info.path
if candidate_filepath.endswith(".py"):
candidate_filepath = candidate_filepath[:-3]
# it is a file, adds it
self._discovered_plugins[".".join((plugin_info.path, "py"))] = candidate_filepath
_discovered[".".join((plugin_info.path, "py"))] = candidate_filepath
else:
log.error("Plugin candidate rejected: cannot find the file or directory module for '%s'" % (candidate_infofile))
break
# print candidate_filepath
_candidates.append((candidate_infofile, candidate_filepath, plugin_info))
# finally the candidate_infofile must not be discovered again
_discovered[candidate_infofile] = candidate_filepath
self._discovered_plugins[candidate_infofile] = candidate_filepath
# print "%s found by strategy %s" % (candidate_filepath, analyzer.name)
return _candidates, len(_candidates)
def loadPlugins(self, callback=None, callback_after=None):
"""
Load the candidate plugins that have been identified through a
previous call to locatePlugins. For each plugin candidate
look for its category, load it and store it in the appropriate
slot of the ``category_mapping``.
You can specify 2 callbacks: callback, and callback_after. If either of these are passed a function, (in the case of callback), it will get called before each plugin load attempt and (for callback_after), after each
attempt. The ``plugin_info`` instance is passed as an argument to
each callback. This is meant to facilitate code that needs to run for each plugin, such as adding the directory it resides in to sys.path (so imports of other files in the plugin's directory work correctly). You can use callback_after to remove anything you added to the path.
"""
# print "%s.loadPlugins" % self.__class__
if not hasattr(self, '_candidates'):
raise ValueError("locatePlugins must be called before loadPlugins")
processed_plugins = []
for candidate_infofile, candidate_filepath, plugin_info in self._candidates:
# make sure to attribute a unique module name to the one
# that is about to be loaded
plugin_module_name_template = NormalizePluginNameForModuleName(
"yapsy_loaded_plugin_" + plugin_info.name) + "_%d"
for plugin_name_suffix in range(len(sys.modules)):
plugin_module_name = plugin_module_name_template % plugin_name_suffix
if plugin_module_name not in sys.modules:
break
# tolerance on the presence (or not) of the py extensions
if candidate_filepath.endswith(".py"):
candidate_filepath = candidate_filepath[:-3]
# if a callback exists, call it before attempting to load
# the plugin so that a message can be displayed to the
# user
if callback is not None:
callback(plugin_info)
# cover the case when the __init__ of a package has been
# explicitely indicated
if "__init__" in os.path.basename(candidate_filepath):
candidate_filepath = os.path.dirname(candidate_filepath)
try:
candidate_module = PluginManager._importModule(
plugin_module_name, candidate_filepath)
except Exception:
exc_info = sys.exc_info()
log.error("Unable to import plugin: %s" % candidate_filepath,
exc_info=exc_info)
plugin_info.error = exc_info
processed_plugins.append(plugin_info)
continue
processed_plugins.append(plugin_info)
if "__init__" in os.path.basename(candidate_filepath):
sys.path.remove(plugin_info.path)
# now try to find and initialise the first subclass of the correct plugin interface
last_failed_attempt_message = None
for element, element_name in ((getattr(candidate_module,
name), name)
for name in dir(candidate_module)):
plugin_info_reference = None
for category_name in self.categories_interfaces:
try:
is_correct_subclass = issubclass(
element, self.categories_interfaces[category_name])
except Exception:
exc_info = sys.exc_info()
log.debug(
"correct subclass tests failed for: %s in %s" %
(element_name, candidate_filepath),
exc_info=exc_info)
continue
if is_correct_subclass and element is not self.categories_interfaces[
category_name]:
current_category = category_name
if candidate_infofile not in self._category_file_mapping[
current_category]:
# we found a new plugin: initialise it and search for the next one
if not plugin_info_reference:
try:
plugin_info.plugin_object = self.instanciateElementWithImportInfo(
element, element_name,
plugin_module_name, candidate_filepath)
plugin_info_reference = plugin_info
except Exception:
exc_info = sys.exc_info()
last_failed_attempt_message = "Unable to create plugin object: %s" % candidate_filepath
log.debug(last_failed_attempt_message,
exc_info=exc_info)
plugin_info.error = exc_info
break # If it didn't work once it wont again
else:
last_failed_attempt_message = None
plugin_info.categories.append(current_category)
self.category_mapping[current_category].append(
plugin_info_reference)
self._category_file_mapping[
current_category].append(candidate_infofile)
# Everything is loaded and instantiated for this plugin now
if callback_after is not None:
callback_after(plugin_info)
else:
if last_failed_attempt_message:
log.error(last_failed_attempt_message,
exc_info=plugin_info.error)
# Remove candidates list since we don't need them any more and
# don't need to take up the space
delattr(self, '_candidates')
return processed_plugins