StorageKey

A StorageKey represents a value that is either New or Existing.

StorageKey is a type that would be used normally as a key in an EveryDict or EveryDictList to indicate if a value is already Existing - that is, stored in the backend, or New.

If used as a key for an EveryDict we are guarnteed to have only a single New.

type StorageKey recordId

= New

| Existing recordId

A StorageKey value is either New or Existing.

view : StorageKey -> Html msg
view storageKey =
    case storageKey of
        Existing recordId ->
            text <| "Record ID is " ++ toString recordId


        ReadOnly saved ->
            text "Record was not saved yet"

isExisting : StorageKey recordId -> Bool

Determines if a StorageKey is of type Existing.

StorageKey.New
    |> StorageKey.isExisting  --> False


StorageKey.Existing "uuid-1234"
    |> StorageKey.isExisting  --> True

isNew : StorageKey recordId -> Bool

Determines if a StorageKey is of type New.

StorageKey.New
    |> StorageKey.isNew  --> True


StorageKey.Existing "uuid-1234"
    |> StorageKey.isNew  --> False

value : StorageKey recordId -> Maybe recordId

Gets the record ID value out of a StorageKey if it is of type Existing. Otherwise, it retuens Nothing.

StorageKey.New
    |> StorageKey.value  --> Nothing


StorageKey.Existing "uuid-1234"
    |> StorageKey.value  --> Just "uuid-1234"

Modules

StorageKey

Gizra/elm-storage-key/1.1.1

StorageKey

Modules