JSON support

graphs supports the serialization of graphs as via circe.

You need to add the graphs-json dependency to use it:

libraryDependencies += "com.flowtick" %% "graphs-json" % "0.8.0"

For the conversion you need to have an Identifiable instance for the node type:

Example: primitive types with defaults

copysourceimport com.flowtick.graphs._
import com.flowtick.graphs.defaults._
import com.flowtick.graphs.json.format.default._
import io.circe._
import io.circe.syntax._
import io.circe.parser._

val graph: Graph[Unit, String] = Graph.fromEdges(
  Set(
    "A" --> "D",
    "A" --> "C",
    "A" --> "B",
    "B" --> "E",
    "B" --> "F",
    "B" --> "G",
    "E" --> "H"
  )
)

val json: Json = graph.asJson
val parsed: Either[Error, Graph[Unit, String]] = decode[Graph[Unit, String]](json.noSpaces)

require(parsed == Right(graph))

Example: providing the ID for a custom type

copysourceimport com.flowtick.graphs._
import com.flowtick.graphs.defaults._
import com.flowtick.graphs.json.format.default._
import io.circe._
import io.circe.generic.auto._
import io.circe.syntax._
import io.circe.parser._

case class MyNode(id: String, value: Double)

implicit val myNodeId: Identifiable[MyNode] = (value: MyNode) => value.id

val graph: Graph[Unit, MyNode] = Graph.fromEdges(
  Set(
    MyNode("1", 42) --> MyNode("2", 43)
  )
)

val json: Json = graph.asJson
val parsed = decode[Graph[Unit, MyNode]](json.noSpaces)

require(parsed == Right(graph))

Note that this example is also importing to option to treat unit as null in the JSON representation.