19.7. Runtime Options
When we call the PDR method createAccount (through the proxy), we would like to be able to tell it whether it is the very first account for a particular person, or a subsequent installation (e.g. on a smartphone, after the original installation was done on a laptop). We have a method for doing so, using 'runtime options'.
In fact, whenever we create a PerspectivesState object to pass along to runPerspectivesWithState, we have to provide a RuntimeOptions value. This data type is defined at the time of writing as
type RuntimeOptions =
-- Default: true. Should be false when someone installs MyContexts on a second device.
{ isFirstInstallation :: Boolean
-- Default: null. Provide a value to test setup of an experimental new System version.
, useSystemVersion :: Nullable String
}
This record type can be extended at will.
Notice that proxy functions providing a RuntimeOptions object should give a member the Javascript null value in order to omit a particular value. Currently, use toMaybe to convert a member like 'useSystemVersion' to a Nothing or Just value.