scanamo

Type Members

1. trait DerivedDynamoFormat extends NoFormatError

   

2. trait DynamoFormat[T] extends Serializable

   

   Type class for defining serialisation to and from DynamoDB's AttributeValue

   Type class for defining serialisation to and from DynamoDB's AttributeValue

   >>> val listOptionFormat = DynamoFormat[List[Option[Int]]]
   >>> listOptionFormat.read(listOptionFormat.write(List(Some(1), None, Some(3))))
   Right(List(Some(1), None, Some(3)))

   Also supports automatic derivation for case classes

   >>> case class Farm(animals: List[String])
   >>> case class Farmer(name: String, age: Long, farm: Farm)
   >>> val farmerF = DynamoFormat[Farmer]
   >>> farmerF.read(farmerF.write(Farmer("McDonald", 156L, Farm(List("sheep", "cow")))))
   Right(Farmer(McDonald,156,Farm(List(sheep, cow))))

   Problems reading a value are detailed

   >>> import cats.syntax.either._
   
   >>> case class Developer(name: String, age: String, problems: Int)
   >>> val invalid = DynamoFormat[Farmer].read(DynamoFormat[Developer].write(Developer("Alice", "none of your business", 99)))
   >>> invalid
   Left(InvalidPropertiesError(NonEmptyList(PropertyReadError(age,NoPropertyOfType(N,{S: none of your business,})), PropertyReadError(farm,MissingProperty))))
   
   >>> invalid.leftMap(cats.Show[error.DynamoReadError].show)
   Left('age': not of type: 'N' was '{S: none of your business,}', 'farm': missing)

   Optional properties are defaulted to None

   >>> case class LargelyOptional(a: Option[String], b: Option[String])
   >>> DynamoFormat[LargelyOptional].read(DynamoFormat[Map[String, String]].write(Map("b" -> "X")))
   Right(LargelyOptional(None,Some(X)))

   Custom formats can often be most easily defined using DynamoFormat.coercedXmap, DynamoFormat.xmap or DynamoFormat.iso

3. class MacroOfLastResort extends AnyRef

   

4. trait NoFormatError extends AnyRef

   

5. trait Queryable[T[_], V] extends AnyRef

   

6. trait Scannable[T[_], V] extends AnyRef

   

7. case class Table[V](name: String)(implicit evidence$1: DynamoFormat[V]) extends Product with Serializable

   

   Represents a DynamoDB table that operations can be performed against

   Represents a DynamoDB table that operations can be performed against

   >>> case class Transport(mode: String, line: String)
   >>> val transport = Table[Transport]("transport")
   
   >>> val client = LocalDynamoDB.client()
   >>> import com.amazonaws.services.dynamodbv2.model.ScalarAttributeType._
   
   >>> LocalDynamoDB.withTable(client)("transport")('mode -> S, 'line -> S) {
   ...   import com.gu.scanamo.syntax._
   ...   val operations = for {
   ...     _ <- transport.putAll(Set(
   ...       Transport("Underground", "Circle"),
   ...       Transport("Underground", "Metropolitan"),
   ...       Transport("Underground", "Central")))
   ...     results <- transport.query('mode -> "Underground" and ('line beginsWith "C"))
   ...   } yield results.toList
   ...   Scanamo.exec(client)(operations)
   ... }
   List(Right(Transport(Underground,Central)), Right(Transport(Underground,Circle)))