state

type Handle ¶

type Handle struct {
	FilePath string
	FileInfo os.FileInfo
	Viper    *viper.Viper
}

A state Handle is used to save and load a stateful object to/from disk. It consists of the path to the state file, the latest information about that file, and a Viper instance to handle reading/writing/unmarshalling the file data.

func (handle *Handle) Initialize(name string, folderPath string, afs *afero.Afero) error

func (handle *Handle) InitializeViper(afs *afero.Afero) bool

func (handle *Handle) Load(state Stateful, afs *afero.Afero) (os.FileInfo, error)

func (handle *Handle) Save(afs *afero.Afero) (os.FileInfo, error)

func (handle *Handle) SetStruct(data any, parent string) error

type Initializable ¶

type Initializable[I any, T any] interface {
	// The Initializable struct should return a pointer to a valid instance of itself with defaults set.
	Initialize() T
}

Initializable structs must be able to load their own defaults. Initializable structs are often included in Stateful structs. When specified in a new type of stateful struct, you must pass the type twice: once as itself, once as a pointer to itself. For Example:

type Instance[D state.Initializable[D, *D]] struct {}

type Kind ¶

type Kind struct {
	Name       string
	FolderName string
}

The Kind of a stateful struct is metadata about the struct and is specified by the application using it. The Name field is used in log messaging/displays about the struct while the FolderName field is used to determine where to save the struct or look for it when loading. If Kind is not specified, the appropriate defaults should be set by the implementation of the stateful struct's Initialize() method.

type MetaConfig ¶

type MetaConfig struct {
	ConfigKey string
	Ignore    bool
}

MetaConfig structs are used when parsing tags on configuration structs; they help turn a mapstructure tag into the name of a viper configuration key and change the behavior of a configuration item via the tympanconfig directive; right now the only supported directive is `tympanconfig:"ignore"` which ensures a struct key is not written to the configuration.

func ParseStructTags(tagEntry reflect.StructTag) (metaConfig MetaConfig)

type Stateful ¶

type Stateful interface {
	// A stateful struct must be initializeable. It is expected that initialize should set the default values for the
	// struct if they are not set, call Initialize on their state handle, load the state from disk if the file already
	// exists or write the default state to disk if it does not. If initalization fails, the method should return an error
	Initialize(name string, rootFolderPath string, afs *afero.Afero) error
	Load(afs *afero.Afero) error
	Save(afs *afero.Afero) error
}

Stateful structs can be initialized, loaded, and saved. All three methods update the struct itself, Initialize and Save may write to disk while Load will only ever read from disk.