# -*- coding: utf-8 -*-
# Copyright 2017 Camptocamp SA
# Copyright 2017 Odoo
# License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl.html)
"""
Core
====
Core classes for the components.
The most common classes used publicly are:
* :class:`Component`
* :class:`AbstractComponent`
* :class:`WorkContext`
"""
import logging
import operator
from collections import defaultdict, OrderedDict
from odoo import models
from odoo.tools import OrderedSet, LastOrderedSet
from .exception import NoComponentError, SeveralComponentError
_logger = logging.getLogger(__name__)
try:
from cachetools import LRUCache, cachedmethod
except ImportError:
_logger.debug("Cannot import 'cachetools'.")
# The Cache size represents the number of items, so the number
# of components (include abstract components) we will keep in the LRU
# cache. We would need stats to know what is the average but this is a bit
# early.
DEFAULT_CACHE_SIZE = 512
# this is duplicated from odoo.models.MetaModel._get_addon_name() which we
# unfortunately can't use because it's an instance method and should have been
# a @staticmethod
def _get_addon_name(full_name):
# The (Odoo) module name can be in the ``odoo.addons`` namespace
# or not. For instance, module ``sale`` can be imported as
# ``odoo.addons.sale`` (the right way) or ``sale`` (for backward
# compatibility).
module_parts = full_name.split('.')
if len(module_parts) > 2 and module_parts[:2] == ['odoo', 'addons']:
addon_name = full_name.split('.')[2]
else:
addon_name = full_name.split('.')[0]
return addon_name
[docs]class ComponentDatabases(dict):
""" Holds a registry of components for each database """
[docs]class ComponentRegistry(object):
""" Store all the components and allow to find them using criteria
The key is the ``_name`` of the components.
This is an OrderedDict, because we want to keep the registration order of
the components, addons loaded first have their components found first.
The :attr:`ready` attribute must be set to ``True`` when all the components
are loaded.
"""
def __init__(self, cachesize=DEFAULT_CACHE_SIZE):
self._cache = LRUCache(maxsize=cachesize)
self._components = OrderedDict()
self._loaded_modules = set()
self.ready = False
def __getitem__(self, key):
return self._components[key]
def __setitem__(self, key, value):
self._components[key] = value
def __contains__(self, key):
return key in self._components
[docs] def get(self, key, default=None):
return self._components.get(key, default)
def __iter__(self):
return iter(self._components)
[docs] def load_components(self, module):
if module in self._loaded_modules:
return
for component_class in MetaComponent._modules_components[module]:
component_class._build_component(self)
self._loaded_modules.add(module)
[docs] @cachedmethod(operator.attrgetter('_cache'))
def lookup(self, collection_name=None, usage=None, model_name=None):
""" Find and return a list of components for a usage
If a component is not registered in a particular collection (no
``_collection``), it will be returned in any case (as far as
the ``usage`` and ``model_name`` match). This is useful to share
generic components across different collections.
If no collection name is given, components from any collection
will be returned.
Then, the components of a collection are filtered by usage and/or
model. The ``_usage`` is mandatory on the components. When the
``_model_name`` is empty, it means it can be used for every models,
and it will ignore the ``model_name`` argument.
The abstract components are never returned.
This is a rather low-level function, usually you will use the
high-level :meth:`AbstractComponent.component`,
:meth:`AbstractComponent.many_components` or even
:meth:`AbstractComponent.component_by_name`.
:param collection_name: the name of the collection the component is
registered into.
:param usage: the usage of component we are looking for
:param model_name: filter on components that apply on this model
"""
# keep the order so addons loaded first have components used first
candidates = (
component for component in self._components.itervalues()
if not component._abstract
)
if collection_name is not None:
candidates = (
component for component in candidates
if (component._collection == collection_name or
component._collection is None)
)
if usage is not None:
candidates = (component for component in candidates
if component._usage == usage)
if model_name is not None:
candidates = (c for c in candidates
if c.apply_on_models is None or
model_name in c.apply_on_models)
return list(candidates)
# We will store a ComponentRegistry per database here,
# it will be cleared and updated when the odoo's registry is rebuilt
_component_databases = ComponentDatabases()
[docs]class WorkContext(object):
""" Transport the context required to work with components
It is propagated through all the components, so any
data or instance (like a random RPC client) that need
to be propagated transversally to the components
should be kept here.
Including:
.. attribute:: model_name
Name of the model we are working with. It means that any lookup for a
component will be done for this model. It also provides a shortcut
as a `model` attribute to use directly with the Odoo model from
the components
.. attribute:: collection
The collection we are working with. The collection is an Odoo
Model that inherit from 'collection.base'. The collection attribute
can be a record or an "empty" model.
.. attribute:: model
Odoo Model for ``model_name`` with the same Odoo
:class:`~odoo.api.Environment` than the ``collection`` attribute.
This is also the entrypoint to work with the components.
::
collection = self.env['my.collection'].browse(1)
work = WorkContext(model_name='res.partner', collection=collection)
component = work.component(usage='record.importer')
Usually you will use the context manager on the ``collection.base`` Model:
::
collection = self.env['my.collection'].browse(1)
with collection.work_on('res.partner') as work:
component = work.component(usage='record.importer')
It supports any arbitrary keyword arguments that will become attributes of
the instance, and be propagated throughout all the components.
::
collection = self.env['my.collection'].browse(1)
with collection.work_on('res.partner', hello='world') as work:
assert work.hello == 'world'
When you need to work on a different model, a new work instance will be
created for you when you are using the high-level API. This is what
happens under the hood:
::
collection = self.env['my.collection'].browse(1)
with collection.work_on('res.partner', hello='world') as work:
assert work.model_name == 'res.partner'
assert work.hello == 'world'
work2 = work.work_on('res.users')
# => spawn a new WorkContext with a copy of the attributes
assert work2.model_name == 'res.users'
assert work2.hello == 'world'
"""
def __init__(self, model_name=None, collection=None,
components_registry=None, **kwargs):
self.collection = collection
self.model_name = model_name
self.model = self.env[model_name]
# lookup components in an alternative registry, used by the tests
if components_registry is not None:
self.components_registry = components_registry
else:
dbname = self.env.cr.dbname
try:
self.components_registry = _component_databases[dbname]
except KeyError:
_logger.error(
'No component registry for database %s. '
'Probably because the Odoo registry has not been built '
'yet.'
)
raise
self._propagate_kwargs = [
'collection',
'model_name',
'components_registry',
]
for attr_name, value in kwargs.iteritems():
setattr(self, attr_name, value)
self._propagate_kwargs.append(attr_name)
@property
def env(self):
""" Return the current Odoo env
This is the environment of the current collection.
"""
return self.collection.env
[docs] def work_on(self, model_name=None, collection=None):
""" Create a new work context for another model keeping attributes
Used when one need to lookup components for another model.
"""
kwargs = {attr_name: getattr(self, attr_name)
for attr_name in self._propagate_kwargs}
if collection is not None:
kwargs['collection'] = collection
if model_name is not None:
kwargs['model_name'] = model_name
return self.__class__(**kwargs)
def _component_class_by_name(self, name):
components_registry = self.components_registry
component_class = components_registry.get(name)
if not component_class:
raise NoComponentError("No component with name '%s' found." % name)
return component_class
[docs] def component_by_name(self, name, model_name=None):
""" Return a component by its name
If the component exists, an instance of it will be returned,
initialized with the current :class:`WorkContext`.
A :exc:`odoo.addons.component.exception.NoComponentError` is raised
if:
* no component with this name exists
* the ``_apply_on`` of the found component does not match
with the current working model
In the latter case, it can be an indication that you need to switch to
a different model, you can do so by providing the ``model_name``
argument.
"""
if isinstance(model_name, models.BaseModel):
model_name = model_name._name
component_class = self._component_class_by_name(name)
work_model = model_name or self.model_name
if (component_class._collection and
self.collection._name != component_class._collection):
raise NoComponentError(
"Component with name '%s' can't be used for collection '%s'."
(name, self.collection._name)
)
if (component_class.apply_on_models and
work_model not in component_class.apply_on_models):
if len(component_class.apply_on_models) == 1:
hint_models = "'%s'" % (component_class.apply_on_models[0],)
else:
hint_models = "<one of %r>" % (
component_class.apply_on_models,
)
raise NoComponentError(
"Component with name '%s' can't be used for model '%s'.\n"
"Hint: you might want to use: "
"component_by_name('%s', model_name=%s)" %
(name, work_model, name, hint_models)
)
if work_model == self.model_name:
work_context = self
else:
work_context = self.work_on(model_name)
return component_class(work_context)
def _lookup_components(self, usage=None, model_name=None):
component_classes = self.components_registry.lookup(
self.collection._name,
usage=usage,
model_name=model_name,
)
return [cls for cls in component_classes if cls._component_match(self)]
[docs] def component(self, usage=None, model_name=None):
""" Find a component by usage and model for the current collection
It searches a component using the rules of
:meth:`ComponentRegistry.lookup`. When a component is found,
it initialize it with the current :class:`WorkContext` and returned.
A component with a ``_apply_on`` matching the asked ``model_name``
takes precedence over a generic component without ``_apply_on``.
A component with a ``_collection`` matching the current collection
takes precedence over a generic component without ``_collection``.
This behavior allows to define generic components across collections
and/or models and override them only for a particular collection and/or
model.
A :exc:`odoo.addons.component.exception.SeveralComponentError` is
raised if more than one component match for the provided
``usage``/``model_name``.
A :exc:`odoo.addons.component.exception.NoComponentError` is raised
if no component is found for the provided ``usage``/``model_name``.
"""
if isinstance(model_name, models.BaseModel):
model_name = model_name._name
model_name = model_name or self.model_name
component_classes = self._lookup_components(
usage=usage, model_name=model_name
)
save_component_classes = component_classes
if not component_classes:
raise NoComponentError(
"No component found for collection '%s', "
"usage '%s', model_name '%s'." %
(self.collection._name, usage, model_name)
)
elif len(component_classes) > 1:
# If we have more than one component, try to find the one
# specifically linked to the collection...
component_classes = [
c for c in component_classes
if c._collection == self.collection._name]
# If the previous match (based on collection) remove every components,
# we have to restore it because maybe the filter based on
# apply_models could match
component_classes = component_classes or save_component_classes
if len(component_classes) > 1:
# ... or try to find the one specifically linked to the model
component_classes = [
c for c in component_classes
if c.apply_on_models and model_name in c.apply_on_models
]
if len(component_classes) != 1:
raise SeveralComponentError(
"Several components found for collection '%s', "
"usage '%s', model_name '%s'. Found: %r" %
(self.collection._name, usage or '',
model_name or '', component_classes)
)
if model_name == self.model_name:
work_context = self
else:
work_context = self.work_on(model_name)
return component_classes[0](work_context)
[docs] def many_components(self, usage=None, model_name=None):
""" Find many components by usage and model for the current collection
It searches a component using the rules of
:meth:`ComponentRegistry.lookup`. When components are found, they
initialized with the current :class:`WorkContext` and returned as a
list.
If no component is found, an empty list is returned.
"""
if isinstance(model_name, models.BaseModel):
model_name = model_name._name
model_name = model_name or self.model_name
component_classes = self._lookup_components(
usage=usage, model_name=model_name
)
if model_name == self.model_name:
work_context = self
else:
work_context = self.work_on(model_name)
return [comp(work_context) for comp in component_classes]
def __str__(self):
return "WorkContext(%s, %s)" % (self.model_name, repr(self.collection))
def __unicode__(self):
return unicode(str(self))
__repr__ = __str__
[docs]class AbstractComponent(object):
""" Main Component Model
All components have a Python inheritance either on
:class:`AbstractComponent` or either on :class:`Component`.
Abstract Components will not be returned by lookups on components, however
they can be used as a base for other Components through inheritance (using
``_inherit``).
Inheritance mechanism
The inheritance mechanism is like the Odoo's one for Models. Each
component has a ``_name``. This is the absolute minimum in a Component
class.
::
class MyComponent(Component):
_name = 'my.component'
def speak(self, message):
print message
Every component implicitly inherit from the `'base'` component.
There are two close but distinct inheritance types, which look
familiar if you already know Odoo. The first uses ``_inherit`` with
an existing name, the name of the component we want to extend. With
the following example, ``my.component`` is now able to speak and to
yell.
::
class MyComponent(Component): # name of the class does not matter
_inherit = 'my.component'
def yell(self, message):
print message.upper()
The second has a different ``_name``, it creates a new component,
including the behavior of the inherited component, but without
modifying it. In the following example, ``my.component`` is still able
to speak and to yell (brough by the previous inherit), but not to
sing. ``another.component`` is able to speak, to yell and to sing.
::
class AnotherComponent(Component):
_name = 'another.component'
_inherit = 'my.component'
def sing(self, message):
print message.upper()
Registration and lookups
It is handled by 3 attributes on the class:
_collection
The name of the collection where we want to register the
component. This is not strictly mandatory as a component can be
shared across several collections. But usually, you want to set a
collection to segregate the components for a domain. A collection
can be for instance ``magento.backend``. It is also the name of a
model that inherits from ``collection.base``. See also
:class:`~WorkContext` and
:class:`~odoo.addons.component.models.collection.Collection`.
_apply_on
List of names or name of the Odoo model(s) for which the component
can be used. When not set, the component can be used on any model.
_usage
The collection and the model (``_apply_on``) will help to filter
the candidate components according to our working context (e.g. I'm
working on ``magento.backend`` with the model
``magento.res.partner``). The usage will define **what** kind of
task the component we are looking for serves to. For instance, it
might be ``record.importer``, ``export.mapper```... but you can be
as creative as you want.
Now, to get a component, you'll likely use
:meth:`WorkContext.component` when you start to work with components
in your flow, but then from within your components, you are more
likely to use one of:
* :meth:`component`
* :meth:`many_components`
* :meth:`component_by_name` (more rarely though)
Declaration of some Components can look like::
class FooBar(models.Model):
_name = 'foo.bar.collection'
_inherit = 'collection.base' # this inherit is required
class FooBarBase(AbstractComponent):
_name = 'foo.bar.base'
_collection = 'foo.bar.collection' # name of the model above
class Foo(Component):
_name = 'foo'
_inherit = 'foo.bar.base' # we will inherit the _collection
_apply_on = 'res.users'
_usage = 'speak'
def utter(self, message):
print message
class Bar(Component):
_name = 'bar'
_inherit = 'foo.bar.base' # we will inherit the _collection
_apply_on = 'res.users'
_usage = 'yell'
def utter(self, message):
print message.upper() + '!!!'
class Vocalizer(Component):
_name = 'vocalizer'
_inherit = 'foo.bar.base'
_usage = 'vocalizer'
# can be used for any model
def vocalize(action, message):
self.component(usage=action).utter(message)
And their usage::
>>> coll = self.env['foo.bar.collection'].browse(1)
>>> with coll.work_on('res.users') as work:
... vocalizer = work.component(usage='vocalizer')
... vocalizer.vocalize('speak', 'hello world')
...
hello world
... vocalizer.vocalize('yell', 'hello world')
HELLO WORLD!!!
Hints:
* If you want to create components without ``_apply_on``, choose a
``_usage`` that will not conflict other existing components.
* Unless this is what you want and in that case you use
:meth:`many_components` which will return all components for a usage
with a matching or a not set ``_apply_on``.
* It is advised to namespace the names of the components (e.g.
``magento.xxx``) to prevent conflicts between addons.
"""
__metaclass__ = MetaComponent
_register = False
_abstract = True
# used for inheritance
_name = None #: Name of the component
#: Name or list of names of the component(s) to inherit from
_inherit = None
#: name of the collection to subscribe in
_collection = None
#: List of models on which the component can be applied.
#: None means any Model, can be a list ['res.users', ...]
_apply_on = None
#: Component purpose ('import.mapper', ...).
_usage = None
def __init__(self, work_context):
super(AbstractComponent, self).__init__()
self.work = work_context
@classmethod
def _component_match(cls, work):
""" Evaluated on candidate components
When a component lookup is done and candidate(s) have
been found for a usage, a final call is done on this method.
If the method return False, the candidate component is ignored.
It can be used for instance to dynamically choose a component
according to a value in the :class:`WorkContext`.
Beware, if the lookups from usage, model and collection are
cached, the calls to :meth:`_component_match` are executed
each time we get components. Heavy computation should be
avoided.
:param work: the :class:`WorkContext` we are working with
"""
return True
@property
def collection(self):
""" Collection we are working with """
return self.work.collection
@property
def env(self):
""" Current Odoo environment, the one of the collection record """
return self.work.env
@property
def model(self):
""" The model instance we are working with """
return self.work.model
[docs] def component_by_name(self, name, model_name=None):
""" Return a component by its name
Shortcut to meth:`~WorkContext.component_by_name`
"""
return self.work.component_by_name(name, model_name=model_name)
[docs] def component(self, usage=None, model_name=None):
""" Return a component
Shortcut to meth:`~WorkContext.component`
"""
return self.work.component(usage=usage, model_name=model_name)
[docs] def many_components(self, usage=None, model_name=None):
""" Return several components
Shortcut to meth:`~WorkContext.many_components`
"""
return self.work.many_components(usage=usage, model_name=model_name)
def __str__(self):
return "Component(%s)" % self._name
def __unicode__(self):
return unicode(str(self))
__repr__ = __str__
@classmethod
def _build_component(cls, registry):
""" Instantiate a given Component in the components registry.
This method is called at the end of the Odoo's registry build. The
caller is :meth:`component.builder.ComponentBuilder.load_components`.
It generates new classes, which will be the Component classes we will
be using. The new classes are generated following the inheritance
of ``_inherit``. It ensures that the ``__bases__`` of the generated
Component classes follow the ``_inherit`` chain.
Once a Component class is created, it adds it in the Component Registry
(:class:`ComponentRegistry`), so it will be available for
lookups.
At the end of new class creation, a hook method
:meth:`_complete_component_build` is called, so you can customize
further the created components. An example can be found in
:meth:`odoo.addons.connector.components.mapper.Mapper._complete_component_build`
The following code is roughly the same than the Odoo's one for
building Models.
"""
# In the simplest case, the component's registry class inherits from
# cls and the other classes that define the component in a flat
# hierarchy. The registry contains the instance ``component`` (on the
# left). Its class, ``ComponentClass``, carries inferred metadata that
# is shared between all the component's instances for this registry
# only.
#
# class A1(Component): Component
# _name = 'a' / | \
# A3 A2 A1
# class A2(Component): \ | /
# _inherit = 'a' ComponentClass
#
# class A3(Component):
# _inherit = 'a'
#
# When a component is extended by '_inherit', its base classes are
# modified to include the current class and the other inherited
# component classes.
# Note that we actually inherit from other ``ComponentClass``, so that
# extensions to an inherited component are immediately visible in the
# current component class, like in the following example:
#
# class A1(Component):
# _name = 'a' Component
# / / \ \
# class B1(Component): / A2 A1 \
# _name = 'b' / \ / \
# B2 ComponentA B1
# class B2(Component): \ | /
# _name = 'b' \ | /
# _inherit = ['b', 'a'] \ | /
# ComponentB
# class A2(Component):
# _inherit = 'a'
# determine inherited components
parents = cls._inherit
if isinstance(parents, basestring):
parents = [parents]
elif parents is None:
parents = []
if cls._name in registry and not parents:
raise TypeError('Component %r (in class %r) already exists. '
'Consider using _inherit instead of _name '
'or using a different _name.' % (cls._name, cls))
# determine the component's name
name = cls._name or (len(parents) == 1 and parents[0])
if not name:
raise TypeError('Component %r must have a _name' % cls)
# all components except 'base' implicitly inherit from 'base'
if name != 'base':
parents = list(parents) + ['base']
# create or retrieve the component's class
if name in parents:
if name not in registry:
raise TypeError("Component %r does not exist in registry." %
name)
ComponentClass = registry[name]
ComponentClass._build_component_check_base(cls)
check_parent = ComponentClass._build_component_check_parent
else:
ComponentClass = type(
name, (AbstractComponent,),
{'_name': name,
'_register': False,
# names of children component
'_inherit_children': OrderedSet()},
)
check_parent = cls._build_component_check_parent
# determine all the classes the component should inherit from
bases = LastOrderedSet([cls])
for parent in parents:
if parent not in registry:
raise TypeError(
"Component %r inherits from non-existing component %r." %
(name, parent)
)
parent_class = registry[parent]
if parent == name:
for base in parent_class.__bases__:
bases.add(base)
else:
check_parent(cls, parent_class)
bases.add(parent_class)
parent_class._inherit_children.add(name)
ComponentClass.__bases__ = tuple(bases)
ComponentClass._complete_component_build()
registry[name] = ComponentClass
return ComponentClass
@classmethod
def _build_component_check_base(cls, extend_cls):
""" Check whether ``cls`` can be extended with ``extend_cls``. """
if cls._abstract and not extend_cls._abstract:
msg = ("%s transforms the abstract component %r into a "
"non-abstract component. "
"That class should either inherit from AbstractComponent, "
"or set a different '_name'.")
raise TypeError(msg % (extend_cls, cls._name))
@classmethod
def _build_component_check_parent(component_class, cls, parent_class):
""" Check whether ``model_class`` can inherit from ``parent_class``.
"""
if component_class._abstract and not parent_class._abstract:
msg = ("In %s, the abstract Component %r cannot inherit "
"from the non-abstract Component %r.")
raise TypeError(
msg % (cls, component_class._name, parent_class._name)
)
@classmethod
def _complete_component_build(cls):
""" Complete build of the new component class
After the component has been built from its bases, this method is
called, and can be used to customize the class before it can be used.
Nothing is done in the base Component, but a Component can inherit
the method to add its own behavior.
"""
[docs]class Component(AbstractComponent):
""" Concrete Component class
This is the class you inherit from when you want your component to
be registered in the component collections.
Look in :class:`AbstractComponent` for more details.
"""
_register = False
_abstract = False