Serialize Option Type for RavenDB.md

F#. Serialization of Option type for RavenDB

Problem

F# Option type is not serialized right for Some(). Example:

Some("Västerås")

to

"Plats": {},

None is serialized to null (right):

"Plats": null,

Solution

Only things I could find.

• F# and Raven DB by Colin Bull.

  Halfway down the page. Source code for converter at GitHub, colinbull/FSharpEnt /src/FSharp.Enterprise/Json.fs

	let customisedStore =
		let customiseSerialiser (s : Raven.Imports.Newtonsoft.Json.JsonSerializer) =
		s.Converters.Add(new Json.MapTypeConverter())
		s.Converters.Add(new Json.UnionTypeConverter())

		let store = new DocumentStore(Url="http://localhost:8080")
		store.Conventions.CustomizeJsonSerializer <- (fun s -> (customiseSerialiser s))
		store.Initialize()

• Json.NET Type Converters for the F# Option, List and Tuple Types by Lev Gorodinski. Description here. Sources on GitHub.

• For me, using the source causes an error:

The type 'Imports.Newtonsoft.Json.JsonSerializer' is not compatible with the type 'JsonSerializer'

To fix it, change your custom converter signature from:

inherit JsonConverter()

to:

inherit Raven.Imports.Newtonsoft.Json.JsonConverter()