Documentation
¶
Index ¶
- Constants
- Variables
- func AddListener(key string, callback func())
- func CanonicalEnvVarName(key string) string
- func EnvOverride(opt Option) (interface{}, string, bool)
- func EnvVarNames(opt Option) []string
- func GetDefault(opt Option) interface{}
- func KnownOption(rule Option) bool
- func NotifyListeners(key string)
- func RegisterHiddenOption(key string, t Type, defaultValue interface{})
- func RegisterOption(key string, t Type, defaultValue interface{}, envAliases ...string)
- func RegisterOptionWithEvents(key string, t Type, defaultValue interface{}, get, set Event)
- type Enums
- type Event
- type Option
- type Registry
- type Type
Constants ¶
const EnvVarPrefix = "ACTIVESTATE_CONFIG_"
EnvVarPrefix is prepended to a config key to derive its canonical environment-variable override.
Variables ¶
var EmptyEvent = func(value interface{}) (interface{}, error) { if enum, ok := value.(*Enums); ok { return enum.Default, nil } return value, nil }
Functions ¶
func AddListener ¶
func AddListener(key string, callback func())
AddListener adds a listener for changes to the given config key that calls the given callback function. Client code is responsible for calling NotifyListeners to signal config changes to listeners.
func CanonicalEnvVarName ¶
CanonicalEnvVarName returns the environment variable that overrides the given config key. Every registered config option can be overridden this way, e.g. "api.host" maps to "ACTIVESTATE_CONFIG_API_HOST".
func EnvOverride ¶
EnvOverride returns the effective override value for the option when one of its environment variables is currently set to a non-empty, valid value, coerced to the option's type. The second return value is the name of the variable in effect; the bool reports whether an override applies.
A variable whose value cannot be strictly coerced to the option's type (an unparseable bool/int or an enum value outside the allowed set) is ignored, so a mis-typed variable falls back to the stored/default value rather than silently changing behavior to a zero value.
func EnvVarNames ¶
EnvVarNames returns every environment variable that can override this option: its canonical ACTIVESTATE_CONFIG_* variable first, followed by any legacy aliases.
func GetDefault ¶
func GetDefault(opt Option) interface{}
func KnownOption ¶
func NotifyListeners ¶
func NotifyListeners(key string)
NotifyListeners notifies listeners that the given config key has changed.
func RegisterHiddenOption ¶
Registers a hidden config option without get/set events.
func RegisterOption ¶
RegisterOption registers a config option without get/set events. Any envAliases are additional legacy/bespoke environment variables that override the option, in addition to its canonical ACTIVESTATE_CONFIG_* variable. They exist only for env vars that predate and do not use the canonical prefix (e.g. ACTIVESTATE_API_HOST).
func RegisterOptionWithEvents ¶
Registers a config option with get/set events.
Types ¶
type Event ¶
type Event func(value interface{}) (interface{}, error)
Event is run when a user tries to set or get a config value via `state config`
type Option ¶
type Option struct {
Name string
Type Type
Default interface{}
// EnvAliases are additional (legacy/bespoke) environment variables that override this option, in
// addition to its canonical CanonicalEnvVarName. They are kept for backwards compatibility with
// env vars that predate the canonical ACTIVESTATE_CONFIG_* scheme (e.g. ACTIVESTATE_API_HOST).
EnvAliases []string
GetEvent Event
SetEvent Event
// contains filtered or unexported fields
}
Option defines what a config value's name and type should be, along with any get/set events
func GetOption ¶
GetOption returns a config option, regardless of whether or not it has been registered. Use KnownOption to determine if the returned option has been previously registered.
func Registered ¶
func Registered() []Option
Registered returns all registered options, excluding hidden ones
Source Files