Yesod.Default.Config

Documentation

data DefaultEnv

A yesod-provided AppEnv, allows for Development, Testing, and Production environments

Constructors

Development

Testing

Staging

Production

Instances

Bounded DefaultEnv

Enum DefaultEnv

Read DefaultEnv

Show DefaultEnv

fromArgs :: (Read env, Show env, Enum env, Bounded env) => (env -> Object -> Parser extra) -> IO (AppConfig env extra)

Load the app config from command line parameters

fromArgsSettings :: (Read env, Show env, Enum env, Bounded env) => (env -> IO (ConfigSettings env extra)) -> IO (AppConfig env extra)

Load the app config from command line parameters, using the given @ConfigSettings.

Since 1.2.2

loadDevelopmentConfig :: IO (AppConfig DefaultEnv ())

Load your development config (when using DefaultEnv)

data AppConfig environment extra

Dynamic per-environment configuration which can be loaded at run-time negating the need to recompile between environments.

Constructors

AppConfig

Fields

appEnv :: environment

appPort :: Int

appRoot :: Text

appHost :: HostPreference

appExtra :: extra

Instances

(Show environment, Show extra) => Show (AppConfig environment extra)

data ConfigSettings environment extra

Constructors

ConfigSettings

Fields

csEnv :: environment

An arbitrary value, used below, to indicate the current running environment. Usually, you will use DefaultEnv for this type.

csParseExtra :: environment -> Object -> Parser extra

Load any extra data, to be used by the application.

csFile :: environment -> IO FilePath

Return the path to the YAML config file.

csGetObject :: environment -> Value -> IO Value

Get the sub-object (if relevant) from the given YAML source which contains the specific settings for the current environment.

configSettings :: Show env => env -> ConfigSettings env ()

Default config settings.

loadConfig :: ConfigSettings environment extra -> IO (AppConfig environment extra)

Load an AppConfig.

Some examples:

-- typical local development
Development:
  host: localhost
  port: 3000

  -- approot: will default to ""

-- typical outward-facing production box
Production:
  host: www.example.com

  -- port: will default 80
  -- host: will default to "*"
  -- approot: will default "http://www.example.com"

-- maybe you're reverse proxying connections to the running app
-- on some other port
Production:
  port: 8080
  approot: "http://example.com"
  host: "localhost"

withYamlEnvironment

Arguments

:: Show e

=> FilePath

the yaml file

-> e

the environment you want to load

-> (Value -> Parser a)

what to do with the mapping

-> IO a

Loads the configuration block in the passed file named by the passed environment, yields to the passed function as a mapping.

Errors in the case of a bad load or if your function returns Nothing.