def load_config(cfg_path, find_config_files, config_loader, loader_callback=None): '''Load configuration file and setup watches Watches are only set up if loader_callback is not None. :param str cfg_path: Path for configuration file that should be loaded. :param function find_config_files: Function that finds configuration file. Check out the description of the return value of ``generate_config_finder`` function. :param ConfigLoader config_loader: Configuration file loader class instance. :param function loader_callback: Function that will be called by config_loader when change to configuration file is detected. :return: Configuration file contents. ''' found_files = find_config_files(cfg_path, config_loader, loader_callback) ret = None for path in found_files: if loader_callback: config_loader.register(loader_callback, path) if ret is None: ret = config_loader.load(path) else: mergedicts(ret, config_loader.load(path)) return ret
def load_config(cfg_path,
find_config_files,
config_loader,
loader_callback=None):
'''Load configuration file and setup watches
Watches are only set up if loader_callback is not None.
:param str cfg_path:
Path for configuration file that should be loaded.
:param function find_config_files:
Function that finds configuration file. Check out the description of
the return value of ``generate_config_finder`` function.
:param ConfigLoader config_loader:
Configuration file loader class instance.
:param function loader_callback:
Function that will be called by config_loader when change to
configuration file is detected.
:return: Configuration file contents.
'''
found_files = find_config_files(cfg_path, config_loader, loader_callback)
ret = None
for path in found_files:
if loader_callback:
config_loader.register(loader_callback, path)
if ret is None:
ret = config_loader.load(path)
else:
mergedicts(ret, config_loader.load(path))
return ret
def load_theme_config(self, name):
r = super(PDBPowerline, self).load_theme_config(name)
theme_overrides = os.environ.get('POWERLINE_THEME_OVERRIDES')
if theme_overrides:
theme_overrides_dict = mergeargs(parse_override_var(theme_overrides))
if name in theme_overrides_dict:
mergedicts(r, theme_overrides_dict[name])
return r
def load_theme_config(self, name):
r = super(PDBPowerline, self).load_theme_config(name)
theme_overrides = os.environ.get('POWERLINE_THEME_OVERRIDES')
if theme_overrides:
theme_overrides_dict = mergeargs(
parse_override_var(theme_overrides))
if name in theme_overrides_dict:
mergedicts(r, theme_overrides_dict[name])
return r
def _override_from(config, override_varname, key=None): try: overrides = vim_getvar(override_varname) except KeyError: return config if key is not None: try: overrides = overrides[key] except KeyError: return config mergedicts(config, overrides) return config
def test_mergedicts(self):
d = {}
mergedicts(d, {'abc': {'def': 'ghi'}})
self.assertEqual(d, {'abc': {'def': 'ghi'}})
mergedicts(d, {'abc': {'def': {'ghi': 'jkl'}}})
self.assertEqual(d, {'abc': {'def': {'ghi': 'jkl'}}})
mergedicts(d, {})
self.assertEqual(d, {'abc': {'def': {'ghi': 'jkl'}}})
mergedicts(d, {'abc': {'mno': 'pqr'}})
self.assertEqual(d, {'abc': {'def': {'ghi': 'jkl'}, 'mno': 'pqr'}})
mergedicts(d, {'abc': {'def': REMOVE_THIS_KEY}})
self.assertEqual(d, {'abc': {'mno': 'pqr'}})
def test_mergedicts(self):
d = {}
mergedicts(d, {'abc': {'def': 'ghi'}})
self.assertEqual(d, {'abc': {'def': 'ghi'}})
mergedicts(d, {'abc': {'def': {'ghi': 'jkl'}}})
self.assertEqual(d, {'abc': {'def': {'ghi': 'jkl'}}})
mergedicts(d, {})
self.assertEqual(d, {'abc': {'def': {'ghi': 'jkl'}}})
mergedicts(d, {'abc': {'mno': 'pqr'}})
self.assertEqual(d, {'abc': {'def': {'ghi': 'jkl'}, 'mno': 'pqr'}})
mergedicts(d, {'abc': {'def': REMOVE_THIS_KEY}})
self.assertEqual(d, {'abc': {'mno': 'pqr'}})
def add_local_theme(self, key, config):
'''Add local themes at runtime (during vim session).
:param str key:
Matcher name (in format ``{matcher_module}.{module_attribute}`` or
``{module_attribute}`` if ``{matcher_module}`` is
``powerline.matchers.vim``). Function pointed by
``{module_attribute}`` should be hashable and accept a dictionary
with information about current buffer and return boolean value
indicating whether current window matched conditions. See also
:ref:`local_themes key description <config-ext-local_themes>`.
:param dict config:
:ref:`Theme <config-themes>` dictionary.
:return:
``True`` if theme was added successfully and ``False`` if theme with
the same matcher already exists.
'''
self.update_renderer()
matcher = self.get_matcher(key)
theme_config = {}
for cfg_path in self.theme_levels:
try:
lvl_config = self.load_config(cfg_path, 'theme')
except IOError:
pass
else:
mergedicts(theme_config, lvl_config)
mergedicts(theme_config, config)
try:
self.renderer.add_local_theme(matcher, {'config': theme_config})
except KeyError:
return False
else:
# Hack for local themes support: when reloading modules it is not
# guaranteed that .add_local_theme will be called once again, so
# this function arguments will be saved here for calling from
# .do_setup().
self.setup_kwargs.setdefault('_local_themes', []).append(
(key, config))
return True
def _load_hierarhical_config(self, cfg_type, levels, ignore_levels):
'''Load and merge multiple configuration files
:param str cfg_type:
Type of the loaded configuration files (e.g. ``colorscheme``,
``theme``).
:param list levels:
Configuration names resembling levels in hierarchy, sorted by
priority. Configuration file names with higher priority should go
last.
:param set ignore_levels:
If only files listed in this variable are present then configuration
file is considered not loaded: at least one file on the level not
listed in this variable must be present.
'''
config = {}
loaded = 0
exceptions = []
for i, cfg_path in enumerate(levels):
try:
lvl_config = self.load_config(cfg_path, cfg_type)
except IOError as e:
if sys.version_info < (3, ):
tb = sys.exc_info()[2]
exceptions.append((e, tb))
else:
exceptions.append(e)
else:
if i not in ignore_levels:
loaded += 1
mergedicts(config, lvl_config)
if not loaded:
for exception in exceptions:
if type(exception) is tuple:
e = exception[0]
else:
e = exception
self.exception('Failed to load %s: {0}' % cfg_type,
e,
exception=exception)
raise e
return config
def add_local_theme(self, key, config):
'''Add local themes at runtime (during vim session).
:param str key:
Matcher name (in format ``{matcher_module}.{module_attribute}`` or
``{module_attribute}`` if ``{matcher_module}`` is
``powerline.matchers.vim``). Function pointed by
``{module_attribute}`` should be hashable and accept a dictionary
with information about current buffer and return boolean value
indicating whether current window matched conditions. See also
:ref:`local_themes key description <config-ext-local_themes>`.
:param dict config:
:ref:`Theme <config-themes>` dictionary.
:return:
``True`` if theme was added successfully and ``False`` if theme with
the same matcher already exists.
'''
self.update_renderer()
matcher = self.get_matcher(key)
theme_config = {}
for cfg_path in self.theme_levels:
try:
lvl_config = self.load_config(cfg_path, 'theme')
except IOError:
pass
else:
mergedicts(theme_config, lvl_config)
mergedicts(theme_config, config)
try:
self.renderer.add_local_theme(matcher, {'config': theme_config})
except KeyError:
return False
else:
# Hack for local themes support: when reloading modules it is not
# guaranteed that .add_local_theme will be called once again, so
# this function arguments will be saved here for calling from
# .do_setup().
self.setup_kwargs.setdefault('_local_themes', []).append((key, config))
return True
def _load_hierarhical_config(self, cfg_type, levels, ignore_levels):
'''Load and merge multiple configuration files
:param str cfg_type:
Type of the loaded configuration files (e.g. ``colorscheme``,
``theme``).
:param list levels:
Configuration names resembling levels in hierarchy, sorted by
priority. Configuration file names with higher priority should go
last.
:param set ignore_levels:
If only files listed in this variable are present then configuration
file is considered not loaded: at least one file on the level not
listed in this variable must be present.
'''
config = {}
loaded = 0
exceptions = []
for i, cfg_path in enumerate(levels):
try:
lvl_config = self.load_config(cfg_path, cfg_type)
except IOError as e:
if sys.version_info < (3,):
tb = sys.exc_info()[2]
exceptions.append((e, tb))
else:
exceptions.append(e)
else:
if i not in ignore_levels:
loaded += 1
mergedicts(config, lvl_config)
if not loaded:
for exception in exceptions:
if type(exception) is tuple:
e = exception[0]
else:
e = exception
self.exception('Failed to load %s: {0}' % cfg_type, e, exception=exception)
raise e
return config
def load_theme_config(self, name):
r = super(ShellPowerline, self).load_theme_config(name)
if self.args.theme_override and name in self.args.theme_override:
mergedicts(r, self.args.theme_override[name])
return r
def load_theme_config(self, name):
r = super(IPythonPowerline, self).load_theme_config(name)
if name in self.theme_overrides:
mergedicts(r, self.theme_overrides[name])
return r
def load_main_config(self):
r = super(IPythonPowerline, self).load_main_config()
if self.config_overrides:
mergedicts(r, self.config_overrides)
return r
def create_renderer(self, load_main=False, load_colors=False, load_colorscheme=False, load_theme=False):
'''(Re)create renderer object. Can be used after Powerline object was
successfully initialized. If any of the below parameters except
``load_main`` is True renderer object will be recreated.
:param bool load_main:
Determines whether main configuration file (:file:`config.json`)
should be loaded. If appropriate configuration changes implies
``load_colorscheme`` and ``load_theme`` and recreation of renderer
object. Won’t trigger recreation if only unrelated configuration
changed.
:param bool load_colors:
Determines whether colors configuration from :file:`colors.json`
should be (re)loaded.
:param bool load_colorscheme:
Determines whether colorscheme configuration should be (re)loaded.
:param bool load_theme:
Determines whether theme configuration should be reloaded.
'''
common_config_differs = False
ext_config_differs = False
if load_main:
self._purge_configs('main')
config = self.load_main_config()
self.common_config = finish_common_config(self.get_encoding(), config['common'])
if self.common_config != self.prev_common_config:
common_config_differs = True
load_theme = (load_theme
or not self.prev_common_config
or self.prev_common_config['default_top_theme'] != self.common_config['default_top_theme'])
self.prev_common_config = self.common_config
self.import_paths = self.common_config['paths']
if not self.logger:
self.logger = self.create_logger()
if not self.pl:
self.pl = PowerlineLogger(self.use_daemon_threads, self.logger, self.ext)
self.config_loader.pl = self.pl
if not self.run_once:
self.config_loader.set_watcher(self.common_config['watcher'])
self.get_module_attr = gen_module_attr_getter(self.pl, self.import_paths, self.imported_modules)
mergedicts(self.renderer_options, dict(
pl=self.pl,
term_truecolor=self.common_config['term_truecolor'],
term_escape_style=self.common_config['term_escape_style'],
ambiwidth=self.common_config['ambiwidth'],
tmux_escape=self.common_config['additional_escapes'] == 'tmux',
screen_escape=self.common_config['additional_escapes'] == 'screen',
theme_kwargs={
'ext': self.ext,
'common_config': self.common_config,
'run_once': self.run_once,
'shutdown_event': self.shutdown_event,
'get_module_attr': self.get_module_attr,
},
))
if not self.run_once and self.common_config['reload_config']:
interval = self.common_config['interval']
self.config_loader.set_interval(interval)
self.run_loader_update = (interval is None)
if interval is not None and not self.config_loader.is_alive():
self.config_loader.start()
self.ext_config = config['ext'][self.ext]
top_theme = (
self.ext_config.get('top_theme')
or self.common_config['default_top_theme']
)
self.theme_levels = (
os.path.join('themes', top_theme),
os.path.join('themes', self.ext, '__main__'),
)
self.renderer_options['theme_kwargs']['top_theme'] = top_theme
if self.ext_config != self.prev_ext_config:
ext_config_differs = True
if (
not self.prev_ext_config
or self.ext_config.get('components') != self.prev_ext_config.get('components')
):
self.setup_components(self.ext_config.get('components'))
if (
not self.prev_ext_config
or self.ext_config.get('local_themes') != self.prev_ext_config.get('local_themes')
):
self.renderer_options['local_themes'] = self.get_local_themes(self.ext_config.get('local_themes'))
load_colorscheme = (
load_colorscheme
or not self.prev_ext_config
or self.prev_ext_config['colorscheme'] != self.ext_config['colorscheme']
)
load_theme = (
load_theme
or not self.prev_ext_config
or self.prev_ext_config['theme'] != self.ext_config['theme']
)
self.prev_ext_config = self.ext_config
create_renderer = load_colors or load_colorscheme or load_theme or common_config_differs or ext_config_differs
if load_colors:
self._purge_configs('colors')
self.colors_config = self.load_colors_config()
if load_colorscheme or load_colors:
self._purge_configs('colorscheme')
if load_colorscheme:
self.colorscheme_config = self.load_colorscheme_config(self.ext_config['colorscheme'])
self.renderer_options['theme_kwargs']['colorscheme'] = (
Colorscheme(self.colorscheme_config, self.colors_config))
if load_theme:
self._purge_configs('theme')
self.renderer_options['theme_config'] = self.load_theme_config(self.ext_config.get('theme', 'default'))
if create_renderer:
Renderer = self.get_module_attr(self.renderer_module, 'renderer')
if not Renderer:
if hasattr(self, 'renderer'):
return
else:
raise ImportError('Failed to obtain renderer')
# Renderer updates configuration file via segments’ .startup thus it
# should be locked to prevent state when configuration was updated,
# but .render still uses old renderer.
try:
renderer = Renderer(**self.renderer_options)
except Exception as e:
self.exception('Failed to construct renderer object: {0}', str(e))
if not hasattr(self, 'renderer'):
raise
else:
self.renderer = renderer
def load_main_config(self):
r = super(PDBPowerline, self).load_main_config()
config_overrides = os.environ.get('POWERLINE_CONFIG_OVERRIDES')
if config_overrides:
mergedicts(r, mergeargs(parse_override_var(config_overrides)))
return r
def create_renderer(self,
load_main=False,
load_colors=False,
load_colorscheme=False,
load_theme=False):
'''(Re)create renderer object. Can be used after Powerline object was
successfully initialized. If any of the below parameters except
``load_main`` is True renderer object will be recreated.
:param bool load_main:
Determines whether main configuration file (:file:`config.json`)
should be loaded. If appropriate configuration changes implies
``load_colorscheme`` and ``load_theme`` and recreation of renderer
object. Won’t trigger recreation if only unrelated configuration
changed.
:param bool load_colors:
Determines whether colors configuration from :file:`colors.json`
should be (re)loaded.
:param bool load_colorscheme:
Determines whether colorscheme configuration should be (re)loaded.
:param bool load_theme:
Determines whether theme configuration should be reloaded.
'''
common_config_differs = False
ext_config_differs = False
if load_main:
self._purge_configs('main')
config = self.load_main_config()
self.common_config = finish_common_config(self.get_encoding(),
config['common'])
if self.common_config != self.prev_common_config:
common_config_differs = True
load_theme = (load_theme or not self.prev_common_config
or self.prev_common_config['default_top_theme']
!= self.common_config['default_top_theme'])
log_keys_differ = (not self.prev_common_config
or (_get_log_keys(self.prev_common_config)
!= _get_log_keys(self.common_config)))
self.prev_common_config = self.common_config
if log_keys_differ:
if self.had_logger:
self.pl = PowerlineLogger(self.use_daemon_threads,
self.logger, self.ext)
self.get_module_attr = gen_module_attr_getter(
self.pl, self.common_config['paths'],
self.imported_modules)
else:
self.logger, self.pl, self.get_module_attr = self.create_logger(
)
self.config_loader.pl = self.pl
if not self.run_once:
self.config_loader.set_watcher(
self.common_config['watcher'])
mergedicts(
self.renderer_options,
dict(
pl=self.pl,
term_truecolor=self.common_config['term_truecolor'],
term_escape_style=self.
common_config['term_escape_style'],
ambiwidth=self.common_config['ambiwidth'],
tmux_escape=self.common_config['additional_escapes'] ==
'tmux',
screen_escape=self.common_config['additional_escapes']
== 'screen',
theme_kwargs={
'ext': self.ext,
'common_config': self.common_config,
'run_once': self.run_once,
'shutdown_event': self.shutdown_event,
'get_module_attr': self.get_module_attr,
},
))
if not self.run_once and self.common_config['reload_config']:
interval = self.common_config['interval']
self.config_loader.set_interval(interval)
self.run_loader_update = (interval is None)
if interval is not None and not self.config_loader.is_alive(
):
self.config_loader.start()
self.ext_config = config['ext'][self.ext]
top_theme = (self.ext_config.get('top_theme')
or self.common_config['default_top_theme'])
self.theme_levels = (
os.path.join('themes', top_theme),
os.path.join('themes', self.ext, '__main__'),
)
self.renderer_options['theme_kwargs']['top_theme'] = top_theme
if self.ext_config != self.prev_ext_config:
ext_config_differs = True
if (not self.prev_ext_config
or self.ext_config.get('components') !=
self.prev_ext_config.get('components')):
self.setup_components(self.ext_config.get('components'))
if (not self.prev_ext_config
or self.ext_config.get('local_themes') !=
self.prev_ext_config.get('local_themes')):
self.renderer_options[
'local_themes'] = self.get_local_themes(
self.ext_config.get('local_themes'))
self.update_interval = self.ext_config.get(
'update_interval', 2)
load_colorscheme = (load_colorscheme
or not self.prev_ext_config
or self.prev_ext_config['colorscheme'] !=
self.ext_config['colorscheme'])
load_theme = (load_theme or not self.prev_ext_config
or self.prev_ext_config['theme'] !=
self.ext_config['theme'])
self.prev_ext_config = self.ext_config
create_renderer = load_colors or load_colorscheme or load_theme or common_config_differs or ext_config_differs
if load_colors:
self._purge_configs('colors')
self.colors_config = self.load_colors_config()
if load_colorscheme or load_colors:
self._purge_configs('colorscheme')
if load_colorscheme:
self.colorscheme_config = self.load_colorscheme_config(
self.ext_config['colorscheme'])
self.renderer_options['theme_kwargs']['colorscheme'] = (
Colorscheme(self.colorscheme_config, self.colors_config))
if load_theme:
self._purge_configs('theme')
self.renderer_options['theme_config'] = self.load_theme_config(
self.ext_config.get('theme', 'default'))
if create_renderer:
Renderer = self.get_module_attr(self.renderer_module, 'renderer')
if not Renderer:
if hasattr(self, 'renderer'):
return
else:
raise ImportError('Failed to obtain renderer')
# Renderer updates configuration file via segments’ .startup thus it
# should be locked to prevent state when configuration was updated,
# but .render still uses old renderer.
try:
renderer = Renderer(**self.renderer_options)
except Exception as e:
self.exception('Failed to construct renderer object: {0}',
str(e))
if not hasattr(self, 'renderer'):
raise
else:
self.renderer = renderer
def load_main_config(self):
r = super(PDBPowerline, self).load_main_config()
config_overrides = os.environ.get('POWERLINE_CONFIG_OVERRIDES')
if config_overrides:
mergedicts(r, mergeargs(parse_override_var(config_overrides)))
return r
def load_theme_config(self, name): r = super(IPythonPowerline, self).load_theme_config(name) if name in self.theme_overrides: mergedicts(r, self.theme_overrides[name]) return r
def load_main_config(self): r = super(ShellPowerline, self).load_main_config() if self.args.config_override: mergedicts(r, self.args.config_override) return r
def load_theme_config(self, name): r = super(ShellPowerline, self).load_theme_config(name) if self.args.theme_override and name in self.args.theme_override: mergedicts(r, self.args.theme_override[name]) return r
def load_main_config(self):
r = super(ShellPowerline, self).load_main_config()
if self.args.config_override:
mergedicts(r, self.args.config_override)
return r
def load_main_config(self): r = super(IPythonPowerline, self).load_main_config() if self.config_overrides: mergedicts(r, self.config_overrides) return r
def create_renderer(self, load_main=False, load_colors=False, load_colorscheme=False, load_theme=False):
"""(Re)create renderer object. Can be used after Powerline object was
successfully initialized. If any of the below parameters except
``load_main`` is True renderer object will be recreated.
:param bool load_main:
Determines whether main configuration file (:file:`config.json`)
should be loaded. If appropriate configuration changes implies
``load_colorscheme`` and ``load_theme`` and recreation of renderer
object. Won’t trigger recreation if only unrelated configuration
changed.
:param bool load_colors:
Determines whether colors configuration from :file:`colors.json`
should be (re)loaded.
:param bool load_colorscheme:
Determines whether colorscheme configuration should be (re)loaded.
:param bool load_theme:
Determines whether theme configuration should be reloaded.
"""
common_config_differs = False
ext_config_differs = False
if load_main:
self._purge_configs("main")
config = self.load_main_config()
self.common_config = finish_common_config(self.get_encoding(), config["common"])
if self.common_config != self.prev_common_config:
common_config_differs = True
load_theme = (
load_theme
or not self.prev_common_config
or self.prev_common_config["default_top_theme"] != self.common_config["default_top_theme"]
)
log_keys_differ = not self.prev_common_config or (
_get_log_keys(self.prev_common_config) != _get_log_keys(self.common_config)
)
self.prev_common_config = self.common_config
if log_keys_differ:
if self.had_logger:
self.pl = PowerlineLogger(self.use_daemon_threads, self.logger, self.ext)
self.get_module_attr = gen_module_attr_getter(
self.pl, self.common_config["paths"], self.imported_modules
)
else:
self.logger, self.pl, self.get_module_attr = self.create_logger()
self.config_loader.pl = self.pl
if not self.run_once:
self.config_loader.set_watcher(self.common_config["watcher"])
mergedicts(
self.renderer_options,
dict(
pl=self.pl,
term_truecolor=self.common_config["term_truecolor"],
term_escape_style=self.common_config["term_escape_style"],
ambiwidth=self.common_config["ambiwidth"],
tmux_escape=self.common_config["additional_escapes"] == "tmux",
screen_escape=self.common_config["additional_escapes"] == "screen",
theme_kwargs={
"ext": self.ext,
"common_config": self.common_config,
"run_once": self.run_once,
"shutdown_event": self.shutdown_event,
"get_module_attr": self.get_module_attr,
},
),
)
if not self.run_once and self.common_config["reload_config"]:
interval = self.common_config["interval"]
self.config_loader.set_interval(interval)
self.run_loader_update = interval is None
if interval is not None and not self.config_loader.is_alive():
self.config_loader.start()
self.ext_config = config["ext"][self.ext]
top_theme = self.ext_config.get("top_theme") or self.common_config["default_top_theme"]
self.theme_levels = (os.path.join("themes", top_theme), os.path.join("themes", self.ext, "__main__"))
self.renderer_options["theme_kwargs"]["top_theme"] = top_theme
if self.ext_config != self.prev_ext_config:
ext_config_differs = True
if not self.prev_ext_config or self.ext_config.get("components") != self.prev_ext_config.get(
"components"
):
self.setup_components(self.ext_config.get("components"))
if not self.prev_ext_config or self.ext_config.get("local_themes") != self.prev_ext_config.get(
"local_themes"
):
self.renderer_options["local_themes"] = self.get_local_themes(self.ext_config.get("local_themes"))
load_colorscheme = (
load_colorscheme
or not self.prev_ext_config
or self.prev_ext_config["colorscheme"] != self.ext_config["colorscheme"]
)
load_theme = (
load_theme or not self.prev_ext_config or self.prev_ext_config["theme"] != self.ext_config["theme"]
)
self.prev_ext_config = self.ext_config
create_renderer = load_colors or load_colorscheme or load_theme or common_config_differs or ext_config_differs
if load_colors:
self._purge_configs("colors")
self.colors_config = self.load_colors_config()
if load_colorscheme or load_colors:
self._purge_configs("colorscheme")
if load_colorscheme:
self.colorscheme_config = self.load_colorscheme_config(self.ext_config["colorscheme"])
self.renderer_options["theme_kwargs"]["colorscheme"] = Colorscheme(
self.colorscheme_config, self.colors_config
)
if load_theme:
self._purge_configs("theme")
self.renderer_options["theme_config"] = self.load_theme_config(self.ext_config.get("theme", "default"))
if create_renderer:
Renderer = self.get_module_attr(self.renderer_module, "renderer")
if not Renderer:
if hasattr(self, "renderer"):
return
else:
raise ImportError("Failed to obtain renderer")
# Renderer updates configuration file via segments’ .startup thus it
# should be locked to prevent state when configuration was updated,
# but .render still uses old renderer.
try:
renderer = Renderer(**self.renderer_options)
except Exception as e:
self.exception("Failed to construct renderer object: {0}", str(e))
if not hasattr(self, "renderer"):
raise
else:
self.renderer = renderer
