gcp-scala-datastore is a simple wrapper library for Google Cloud Datastore.
The library provides asynchronous API and supports the following types of fields in model classes:
ByteIntLongFloatDoubleStringBooleanjava.util.Datecom.google.cloud.datastore.DateTimecom.google.cloud.datastore.LatLngcom.google.cloud.datastore.Blobjava.time.LocalDateTime*java.time.ZonedDateTime*java.time.OffsetDateTime*scala.Option[T]whereTis one of types listed above- any other type that inherits
scala.Serializable. In this case, such fields are converted into Blob in Google Cloud Console.
* java.time.* classes are converted into String at the moment. Thus, they do not work with comparison operators, i.e. |<|, |>|, |==| etc.
To be stored in Cloud Datastore a model class must inherit io.applicative.datastore.BaseEntity and must have id field of type Long or String.
import io.applicative.datastore.{BaseEntity, DatastoreService}
import io.applicative.datastore.util.reflection._
import io.applicative.datastore.query._
import scala.concurrent.Future
// Sample model class
case class Item(id: Long, name: String, price: Double, size: Int, brand: Option[String]) extends BaseEntity
val item = Item(1, "foo", 20.0, 2, None)
// Save
DatastoreService.add[Item](item)
// Save with autogenerated id
for {
key <- DatastoreService.newKey[Item]()
user <- DatastoreService.add[Item](Item(key.id.get, "foo", 20.0, 2, None))
} yield user
// Update
DatastoreService.update[Item](item.copy(brand = Some("bar")))
// Delete
DatastoreService.delete[Item](List(1L))
// Get one by id
DatastoreService.get[Item](1)
// or
select[Item] asSingle
// Select
val items: Future[List[Item]] = select[Item] where "size" |>| 23 and "price" |<=| 200.2 ascOrderBy "size" descOrderBy "price" asList
val items2: Future[List[Item]] = select[Item]
.where("size" |>| 23)
.and("price" |<| 200.2)
.ascOrderBy("size")
.descOrderBy("price")
.asList
val singleItem: Future[Option[Item]] = select[Item] where "name" |==| "foo" asSingle
By default, Cloud Datastore automatically predefines an index for each property of each entity kind(see https://cloud.google.com/datastore/docs/concepts/indexes for more details).
If you want to exclude any of your properties from the indexes, just add the annotation @excludeFromIndexes.
import io.applicative.datastore.BaseEntity
import io.applicative.datastore.util.reflection.excludeFromIndexes
case class Item(id: Long, name: String, price: Double, size: Int, brand: Option[String], @excludeFromIndexes description: String) extends BaseEntity
By default, each model class has kind that consists of class' package and class' name. Let's consider a simple case class Foo
package com.foo.bar
import io.applicative.datastore.BaseEntity
case class Foo(id: Long) extends BaseEntity
In this case, the kind for class Foo will be com.foo.bar.Foo.
It is allowed to set up a custom kind by annotating a class with io.applicative.datastore.reflection.Kind annotation:
package com.foo.bar
import io.applicative.datastore.BaseEntity
import io.applicative.datastore.reflection.Kind
@Kind(value = "JustFoo")
case class Foo(id: Long) extends BaseEntity
In this case, the kind for the class Foo will be JustFoo
The package is available on Maven Central. You can add it as a normal sbt dependency:
libraryDependencies ++= Seq(
"io.applicative" %% "datastore-scala-wrapper" % "1.0-rc11"
)