dlab_core.containers

Module Contents

LC_ERR_CANNOT_OVERRIDE_FROZEN = Cannot override frozen service "{key}".

exception ContainerException

Bases: dlab_core.domain.exceptions.DLabException

Base Container Exceptions. Raised during container execution.

exception ContainerTypeException

Bases: dlab_core.containers.ContainerException

Raised when try to assign wrong data type.

exception ContainerFrozenServiceException(key)

Bases: dlab_core.containers.ContainerException

Raised when try to access a key that is represent frozen data in a dictionary (dict).

exception ContainerKeyException

Bases: dlab_core.containers.ContainerException

Raised when try to access a key that isn’t in a dictionary (dict).

exception ContainerExpectedCallableException

Bases: dlab_core.containers.ContainerException

Raised when trying to call non callable object.

class Container(args=None)

Instantiates the container. Objects and parameters can be passed as argument to the constructor.

Parameters:args (dict) – The parameters or objects. Raises:ContainerTypeException – Handle wrong input data type.

__setitem__(self, key, value)

Sets a parameter or an object. Objects must be defined as Closures. Allowing any python callable leads to difficult to debug problems as function names (strings) are callable (creating a function with the same name as an existing parameter would break your container).

Parameters:

• key (str) – The unique identifier for the parameter or object.
• value – The value or a closure of the parameter.

Raises:

ContainerFrozenServiceException – Prevent override of a frozen

data.

__getitem__(self, key)

Gets a parameter or an object.

Parameters:key (string) – The unique identifier for the parameter or object. Returns:The value of the parameter or an object. Raises:ContainerKeyException – Do not allow to get out of scope element.

keys(self)

Return set-like object providing a view on container keys.

Return type:set Returns:Container keys list.

__len__(self)

Count elements of an object.

Return type:int Returns:The custom count as an integer.

__delitem__(self, key)

Unset element from container

Parameters:key (string) – The unique identifier for the parameter or object. Raises:ContainerKeyException – Do not allow to get out of scope element.

clear(self)

Remove all items from container.

__iter__(self)

Get an iterator from an Container object.

Return type:iterator Returns:Iterator object that loops through each element in the object.

raw(self, key)

Gets a parameter or the closure defining an object.

Parameters:key (string) – The unique identifier for the parameter or object. Returns:The value of the parameter or the closure defining an object: Raises:ContainerKeyException – Do not allow to get out of scope element.

protect(self, call)

Protects a callable from being interpreted as a service. This is useful when you want to store a callable as a parameter.

Parameters:call (function) – A callable to protect from being evaluated. Return type:callable Returns:The passed callable. Raises:ContainerExpectedCallableException – Protect from call non

callable object.

factory(self, call)

Marks a callable as being a factory service.

Parameters:call (function) – A service definition to be used as a factory.

:rtype callable :return: The passed callable

Raises:ContainerExpectedCallableException – Protect from call non

callable object.

extend(self, key, call)

Extends an object definition. Useful when you want to extend an existing object definition, without necessarily loading that object.

Parameters:

• key (string) – The unique identifier for the parameter or object.
• call (callable) – The passed callable.

Return type:

callable

Returns:

The wrapped callable.

Raises:

ContainerFrozenServiceException – Prevent extend of a frozen

data. :raise ContainerExpectedCallableException: Protect from call non callable object.