Scala wrapper for tinkerpop blueprints, this library provide more scalastic code when working with graph database supported by blueprints.
For installation see install section. More working and complete examples can be found on specs test.
Creating new vertex:
case class Person(name:String, kind:String)
val hercules = Person("hercules", "demigod")
db.save(hercules)If your class subclassing from DbObject you will have more sweet code like using save() directly:
case class Person(name:String, kind:String) extends DbObject
val hercules = Person("hercules", "demigod").save()The save() method return a Vertex object, if you want to get class back just:
val herculesObject = hercules.toCC[Person].getCreating edges:
hercules --> "father" --> jupiter
hercules --> "mother" --> alcmeneOr you can also add multiple edges in one line:
hercules --> "father" --> jupiter --> "father" --> saturnCreating mutual (both) edges:
jupiter <--> "brother" <--> neptuneOr more complex mutual edges:
jupiter <--> "brother" <--> neptune <--> "brother" <--> plutoShorthand property getter and setter:
jupiter.set("kind", "god")
val kind = jupiter.get[String]("kind").getGetter get return Option instance, so you can handle unexpected return data efficiently using map:
jupiter.get[String]("kind") map { kind =>
// do with kind here
}Or getting value by using default value if empty:
jupiter.getOrElse[String]("status", "live")Easy getting mutual connection, for example jupiter and pluto is brother both has IN and OUT edges,
is very easy to get mutual connection using mutual method:
val jupitersBrothers = jupiter.mutual("brother")Inspect helpers to print vertex list:
jupitersBrothers.printDump("jupiter brothers:", "name")
// will produce output:
jupiter brothers:
+ neptune
+ plutoUsing Gremlin Pipeline like a boss:
val battled = hercules.pipe.out("battled")
battled.printDump("hercules battled:", "name")
// output:
hercules battled:
+ nemean
+ hydra
+ cerberusSyntactic sugar filtering on Gremlin Pipeline:
// get monster battled with hercules more than 5 times
val monsters = hercules.pipe.outE("battled").wrap.filter { edge =>
edge.getOrElse[Int]("time", 0).toString.toInt > 5
}Returning edges from chain by adding < on the last line:
var edge = hercules --> "battled" --> hydra <
edge.set("time", 2)Using transaction:
transact {
hercules --> "father" --> jupiter
hercules --> "mother" --> alcmene
val edge = hercules --> "battled" --> hydra <
edge.set("time", 15)
}Want more attributes that not fit for case class constructor parameter?
Use @Persistent annotation:
case class City(name:String){
@Persistent var province = "Jakarta" // this attribute will be saved
@Persistent var country = "Indonesia" // this attribute will be saved
val code = 123 // this not
}
Support inheritance as well:
abstract class City(name:String) {
@Persistent var province = ""
}
trait Street {
@Persistent var street = ""
}
trait Code {
@Persistent var postalCode = 0
}
case class Jakarta extends City("Jakarta") with Street with Code with DbObject
// usage
val address = Jakarta()
address.province = "Jakarta Barat" // this will be saved
address.street = "KS. Tubun" // this will be saved
address.postalCode = 12345 // this will be saved
address.save()
// getting back
db.getVertex(address.getVertex.getId).toCC[Jakarta] map { adr =>
println(adr.province) // will printed `Jakarta Barat`
println(adr.postalCode) // will printed `12345`
}
// instantiate to parent class
// this is valid
db.getVertex(address.getVertex.getId).toCC[City] map { adr =>
println(adr.province) // will printed `Jakarta Barat`
}
// this also valid
db.getVertex(address.getVertex.getId).toCC[Street] map { adr =>
println(adr.street) // will printed `KS. Tubun`
}
How it work? All you needs is to adding dependency (see install), import it, and summon Graph db instance with implicit:
import com.ansvia.graph.BlueprintsWrapper._
// you can use any graph database that support tinkerpop blueprints
// here is i'm using simple in-memory Tinkergraph db for example.
implicit val db = TinkerGraphFactory.createTinkerGraph()
//... work here ....Done, now you can using Scalastic sweet syntactic sugar code.
Add dependency:
"com.ansvia.graph" %% "blueprints-scala" % "0.1.17"
for snapshot:
"com.ansvia.graph" %% "blueprints-scala" % "0.1.37-20150226-SNAPSHOT"
[] Robin Syihab