SubConfigKeyTransformer

class tollan.config.SubConfigKeyTransformer

Bases: Generic

Mixin for handlers that extract a subkey from runtime config.

This provides a convenient pattern for handlers that manage a specific section of the runtime config identified by a key.

The subconfig_key is automatically inferred from Literal type parameters.

Type Parameters:

KeyT: Literal type specifying the subconfig key

(e.g., Literal[“database”])

Example

>>> from typing import Literal
>>> from pydantic import BaseModel
>>> from tollan.config import (
...     ConfigHandler,
...     SubConfigKeyTransformer,
...     RuntimeContext,
... )
>>>
>>> class DatabaseConfig(BaseModel):
...     url: str
>>>
>>> class DatabaseHandler(
...     SubConfigKeyTransformer[Literal["database"]],
...     ConfigHandler[DatabaseConfig]
... ):
...     pass
>>>
>>> rc = RuntimeContext(
...     config_sources=[
...         {
...             "format": "dict",
...             "source": {"database": {"url": "postgresql://localhost"}},
...             "order": 0,
...         }
...     ]
... )
>>> handler = DatabaseHandler(rc)
>>> handler.config.url
'postgresql://localhost'

Methods Summary

prepare_config_data(runtime_config)	Extract subconfig data by key.
prepare_runtime_config_data(config_data)	Wrap config data under subconfig key.

Methods Documentation

classmethod prepare_config_data(runtime_config: RuntimeConfig) → dict

Extract subconfig data by key.

Parameters:

runtime_config (RuntimeConfig) – RuntimeConfig model instance

Returns:

Subconfig data dict

Return type:

dict

classmethod prepare_runtime_config_data(config_data: dict) → dict

Wrap config data under subconfig key.

Parameters:

config_data (dict) – Domain config data

Returns:

Runtime config data with subkey

Return type:

dict