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Inverter Factory API

sweet_tea.inverter_factory.InverterFactory

Bases: BaseFactory

Factory class for retrieving class definitions instead of instances.

This factory provides the core functionality for finding registered classes from the registry with optional filtering by library and label, but returns the class definition itself rather than an instantiated object. This gives the caller complete control over when and how to instantiate the class.

Useful for: - Lazy construction patterns - Dependency injection frameworks - Cases where instantiation parameters need to be determined later - Metaprogramming scenarios

Source code in sweet_tea/inverter_factory.py 
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class InverterFactory(BaseFactory):
    """
    Factory class for retrieving class definitions instead of instances.

    This factory provides the core functionality for finding registered classes
    from the registry with optional filtering by library and label, but returns
    the class definition itself rather than an instantiated object. This gives
    the caller complete control over when and how to instantiate the class.

    Useful for:
    - Lazy construction patterns
    - Dependency injection frameworks
    - Cases where instantiation parameters need to be determined later
    - Metaprogramming scenarios
    """

    _logger = logging.getLogger(__name__)

    @classmethod
    def create(
        cls,
        key: str,
        library: str = "",
        label: str = "",
    ) -> Type[Any]:
        """
        Retrieve the class definition for a registered class.

        Args:
            key: Name to reference the class from the registry.
            library: Optional library filter for the class.
            label: Optional label filter for the class.

        Returns:
            The class definition that can be instantiated by the caller.

        Raises:
            SweetTeaError: When the key is not found or filters don't match.
        """
        # Find all entries that have the specified key value (try multiple variations)
        entries = []
        key_variations = cls._generate_key_variations(key)
        for variation in key_variations:
            entries.extend(
                [entry for entry in cls._registry.entries() if entry.key == variation]
            )
            if entries:  # Found entries with this variation
                break

        return cls._create_from_entries(entries, key, library, label)

    @classmethod
    def _create_from_entries(
        cls,
        entries: list[Entry],
        key: str,
        library: str,
        label: str,
    ) -> Type[Any]:
        """
        Retrieve class definition from a filtered list of entries.

        Args:
            entries: List of candidate entries.
            key: The requested key.
            library: Library filter (empty string means no filter).
            label: Label filter (empty string means no filter).

        Returns:
            The class definition from the matching entry.

        Raises:
            SweetTeaError: When no matching entry is found or multiple entries remain after filtering.
        """
        if len(entries) == 0:
            error_message = f"The key {key} not present."
            cls._logger.error(error_message)
            raise SweetTeaError(error_message)

        # If a library filter was specified, filter entries by library
        if library:
            entries = [entry for entry in entries if entry.library == library.lower()]
            if len(entries) == 0:
                error_message = f"The library {library} not present for key {key}."
                cls._logger.error(error_message)
                raise SweetTeaError(error_message)

        # If a label filter was specified, filter entries by label
        if label:
            entries = [entry for entry in entries if entry.label == label.lower()]
            if len(entries) == 0:
                error_message = f"The label {label} not present for key {key}."
                cls._logger.error(error_message)
                raise SweetTeaError(error_message)

        # If more than one entry remains, the filters are insufficient
        if len(entries) > 1:
            error_message = (
                f"The combination of key {key}, label {label}, and library {library} did not return "
                f"a unique result. A total of {len(entries)} possible entries were found."
            )
            cls._logger.error(error_message)
            raise SweetTeaError(error_message)

        # Return the class definition (not instantiated)
        return entries[0].class_def

create(key, library='', label='') classmethod

Retrieve the class definition for a registered class.

Parameters:

Name Type Description Default
key str

Name to reference the class from the registry.

 required
library str

Optional library filter for the class.

 ''
label str

Optional label filter for the class.

 ''

Returns:

Type Description
Type[Any]

The class definition that can be instantiated by the caller.

Raises:

Type Description
SweetTeaError

When the key is not found or filters don't match.
Source code in sweet_tea/inverter_factory.py 
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@classmethod
def create(
    cls,
    key: str,
    library: str = "",
    label: str = "",
) -> Type[Any]:
    """
    Retrieve the class definition for a registered class.

    Args:
        key: Name to reference the class from the registry.
        library: Optional library filter for the class.
        label: Optional label filter for the class.

    Returns:
        The class definition that can be instantiated by the caller.

    Raises:
        SweetTeaError: When the key is not found or filters don't match.
    """
    # Find all entries that have the specified key value (try multiple variations)
    entries = []
    key_variations = cls._generate_key_variations(key)
    for variation in key_variations:
        entries.extend(
            [entry for entry in cls._registry.entries() if entry.key == variation]
        )
        if entries:  # Found entries with this variation
            break

    return cls._create_from_entries(entries, key, library, label)

Methods

create()

sweet_tea.inverter_factory.InverterFactory.create(key, library='', label='') classmethod

Retrieve the class definition for a registered class.

Parameters:

Name Type Description Default
key str

Name to reference the class from the registry.

 required
library str

Optional library filter for the class.

 ''
label str

Optional label filter for the class.

 ''

Returns:

Type Description
Type[Any]

The class definition that can be instantiated by the caller.

Raises:

Type Description
SweetTeaError

When the key is not found or filters don't match.
Source code in sweet_tea/inverter_factory.py 
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@classmethod
def create(
    cls,
    key: str,
    library: str = "",
    label: str = "",
) -> Type[Any]:
    """
    Retrieve the class definition for a registered class.

    Args:
        key: Name to reference the class from the registry.
        library: Optional library filter for the class.
        label: Optional label filter for the class.

    Returns:
        The class definition that can be instantiated by the caller.

    Raises:
        SweetTeaError: When the key is not found or filters don't match.
    """
    # Find all entries that have the specified key value (try multiple variations)
    entries = []
    key_variations = cls._generate_key_variations(key)
    for variation in key_variations:
        entries.extend(
            [entry for entry in cls._registry.entries() if entry.key == variation]
        )
        if entries:  # Found entries with this variation
            break

    return cls._create_from_entries(entries, key, library, label)