Source code for evennia.utils.containers
"""
Containers
Containers are storage classes usually initialized from a setting. They
represent Singletons and acts as a convenient place to find resources (
available as properties on the singleton)
evennia.GLOBAL_SCRIPTS
evennia.OPTION_CLASSES
"""
from pickle import dumps
from django.conf import settings
from django.db.utils import OperationalError, ProgrammingError
from evennia.utils import logger
from evennia.utils.utils import callables_from_module, class_from_module
SCRIPTDB = None
[docs]class Container:
"""
Base container class. A container is simply a storage object whose
properties can be acquired as a property on it. This is generally
considered a read-only affair.
The container is initialized by a list of modules containing callables.
"""
storage_modules = []
[docs] def __init__(self):
"""
Read data from module.
"""
self.loaded_data = None
[docs] def load_data(self):
"""
Delayed import to avoid eventual circular imports from inside
the storage modules.
"""
if self.loaded_data is None:
self.loaded_data = {}
for module in self.storage_modules:
self.loaded_data.update(callables_from_module(module))
def __getattr__(self, key):
return self.get(key)
[docs] def get(self, key, default=None):
"""
Retrive data by key (in case of not knowing it beforehand).
Args:
key (str): The name of the script.
default (any, optional): Value to return if key is not found.
Returns:
any (any): The data loaded on this container.
"""
self.load_data()
return self.loaded_data.get(key, default)
[docs] def all(self):
"""
Get all stored data
Returns:
scripts (list): All global script objects stored on the container.
"""
self.load_data()
return list(self.loaded_data.values())
[docs]class OptionContainer(Container):
"""
Loads and stores the final list of OPTION CLASSES.
Can access these as properties or dictionary-contents.
"""
storage_modules = settings.OPTION_CLASS_MODULES
[docs]class GlobalScriptContainer(Container):
"""
Simple Handler object loaded by the Evennia API to contain and manage a
game's Global Scripts. This will list global Scripts created on their own
but will also auto-(re)create scripts defined in `settings.GLOBAL_SCRIPTS`.
Example:
import evennia
evennia.GLOBAL_SCRIPTS.scriptname
Note:
This does not use much of the BaseContainer since it's not loading
callables from settings but a custom dict of tuples.
"""
[docs] def __init__(self):
"""
Note: We must delay loading of typeclasses since this module may get
initialized before Scripts are actually initialized.
"""
self.typeclass_storage = None
self.loaded_data = {
key: {} if data is None else data for key, data in settings.GLOBAL_SCRIPTS.items()
}
def _get_scripts(self, key=None, default=None):
global SCRIPTDB
if not SCRIPTDB:
from evennia.scripts.models import ScriptDB as SCRIPTDB
if key:
try:
return SCRIPTDB.objects.get(db_key__exact=key, db_obj__isnull=True)
except SCRIPTDB.DoesNotExist:
return default
else:
return SCRIPTDB.objects.filter(db_obj__isnull=True)
def _load_script(self, key):
self.load_data()
typeclass = self.typeclass_storage[key]
script = typeclass.objects.filter(
db_key=key, db_account__isnull=True, db_obj__isnull=True
).first()
kwargs = {**self.loaded_data[key]}
kwargs["key"] = key
kwargs["persistent"] = kwargs.get("persistent", True)
compare_hash = str(dumps(kwargs, protocol=4))
if script:
script_hash = script.attributes.get("global_script_settings", category="settings_hash")
if script_hash is None:
# legacy - store the hash anew and assume no change
script.attributes.add(
"global_script_settings", compare_hash, category="settings_hash"
)
elif script_hash != compare_hash:
# wipe the old version and create anew
logger.log_info(f"GLOBAL_SCRIPTS: Settings changed for {key} ({typeclass}).")
script.stop()
script.delete()
script = None
if not script:
logger.log_info(f"GLOBAL_SCRIPTS: (Re)creating {key} ({typeclass}).")
script, errors = typeclass.create(**kwargs)
if errors:
logger.log_err("\n".join(errors))
return None
# store a hash representation of the setup
script.attributes.add("_global_script_settings", compare_hash, category="settings_hash")
return script
[docs] def start(self):
"""
Called last in evennia.__init__ to initialize the container late
(after script typeclasses have finished loading).
We include all global scripts in the handler and
make sure to auto-load time-based scripts.
"""
# populate self.typeclass_storage
self.load_data()
# make sure settings-defined scripts are loaded
for key in self.loaded_data:
self._load_script(key)
# start all global scripts
try:
for script in self._get_scripts():
script.start()
except (OperationalError, ProgrammingError):
# this can happen if db is not loaded yet (such as when building docs)
pass
[docs] def load_data(self):
"""
This delayed import avoids trying to load Scripts before they are
initialized.
"""
if self.typeclass_storage is None:
self.typeclass_storage = {}
for key, data in list(self.loaded_data.items()):
typeclass = data.get("typeclass", settings.BASE_SCRIPT_TYPECLASS)
self.typeclass_storage[key] = class_from_module(
typeclass, fallback=settings.BASE_SCRIPT_TYPECLASS
)
[docs] def get(self, key, default=None):
"""
Retrive data by key (in case of not knowing it beforehand). Any
scripts that are in settings.GLOBAL_SCRIPTS that are not found
will be recreated on-demand.
Args:
key (str): The name of the script.
default (any, optional): Value to return if key is not found
at all on this container (i.e it cannot be loaded at all).
Returns:
any (any): The data loaded on this container.
"""
res = self._get_scripts(key)
if not res:
if key in self.loaded_data:
if key not in self.typeclass_storage:
# this means we are trying to load in a loop
raise RuntimeError(
f"Trying to access `GLOBAL_SCRIPTS.{key}` before scripts have finished "
"initializing. This can happen if accessing GLOBAL_SCRIPTS from the same "
"module the script is defined in."
)
# recreate if we have the info
return self._load_script(key) or default
return default
return res
[docs] def all(self):
"""
Get all global scripts. Note that this will not auto-start
scripts defined in settings.
Returns:
scripts (list): All global script objects stored on the container.
"""
self.typeclass_storage = None
self.load_data()
for key in self.loaded_data:
self._load_script(key)
return self._get_scripts(None)
# Create all singletons
GLOBAL_SCRIPTS = GlobalScriptContainer()
OPTION_CLASSES = OptionContainer()
