Configuration Parameters

Wireup containers can store configuration parameters that services can inject. This enables self-contained service definition without having to create factories for every service.

Setting up parameters

When creating a container, provide a dictionary of configuration parameters.

import wireup

container = wireup.create_sync_container(
    parameters={
        "database_url": "postgresql://localhost:5432/app",
        "env": "production",
        "debug_mode": True,
        "max_connections": 100,
        "allowed_hosts": ["localhost", "example.com"]
    }
)

Injecting parameters

By name

Inject a specific parameter by name using Inject(param="parameter_name"):

from typing import Annotated
from wireup import service, Inject

@service
class DatabaseService:
    def __init__(
        self,
        url: Annotated[str, Inject(param="database_url")],
        max_connections: Annotated[int, Inject(param="max_connections")]
    ) -> None:
        self.url = url
        self.max_connections = max_connections

Using expressions

Create dynamic configuration values by interpolating parameters using ${parameter_name} syntax:

@service
class FileStorageService:
    def __init__(
        self, 
        upload_path: Annotated[str, Inject(expr="/tmp/uploads/${env}")]
    ) -> None:
        # upload_path = "/tmp/uploads/production"
        self.upload_path = upload_path

Expression results are strings

Parameter expressions always return strings. Non-string parameters are converted using str() before interpolation.

For more complex configuration scenarios or to keep domain objects free of annotations, see the Annotation-Free Architecture guide.