I'm trying to receive some filter list as query param of a get request, which is also an enum on my controller. To do so, I'm using play framework with scala. The problem is: I can't putting the enum type as query param on it, because IDE doesn't recognize as a valid type.
So, I have something like this on routes file
GET /service-orders/ controllers.ServiceOrdersController.listServiceOrders(status: ServiceStatus)
My enum file:
object ServiceStatus extends Enumeration {
type ServiceStatus = Value
val Pending = Value("pending")
val Started = Value("started")
val Completed = Value("completed")
val Error = Value("error")
}
On build.sbt, I use this trying to inject package on routes file
routesImport ++= Seq(
"serviceOrders.models.ServiceStatus"
),
I tried a lot of things, but with no success. I read in some place that I could use QueryStringBindable function, but I can't did this works well... Can you guys please help me to solve this?
Edit: Btw, there's a way to check if status is contained on a list of filters without making this?
.filter {
serviceOrder =>
status.map(serviceOrder.serviceStatus === _)
.reduceOption(_ || _)
.getOrElse(true: Rep[Boolean])
}
This was the only way I could thought to filter status by a list of filters received as query param from API.
You can implement the QueryStringBindable instance like so:
package serviceOrders.models
object ServiceStatus extends Enumeration {
type ServiceStatus = Value
val Pending = Value("pending")
val Started = Value("started")
val Completed = Value("completed")
val Error = Value("error")
implicit val queryStringBindable: QueryStringBindable[ServiceStatus] =
new QueryStringBindable[ServiceStatus] {
override def bind(
key: String,
params: Map[String, Seq[String]]
): Option[Either[String, ServiceStatus]] =
params.get(key).collect {
case Seq(s) =>
ServiceStatus.values.find(_.toString == s).toRight("invalid value")
}
override def unbind(key: String, value: ServiceStatus): String =
implicitly[QueryStringBindable[String]].unbind(key, value.toString)
}
}
In build.sbt you need this:
routesImport ++= Seq("serviceOrders.models.ServiceStatus._")
And this in your routes file:
GET /some/route controllers.SomeController.index(status: ServiceStatus)
Then you can create an index method that takes a ServiceStatus parameter in SomeController and Play will take care of the query parameters.
// edit:
You could actually use the QueryStringBindable.Parsing class to simplify the implementation further.
Related
I try to write a unit test for a small function in a controller using Play/ScalaTest+ Play. The function I want to test looks like this:
def functionToTest(id: String) = Action.async {
implicit request =>
lang
deeperFunction{ implicit context =>
...
}
}
The deeperFunction
def deeperFunction(block: Context => Future[Result])(implicit request: RequestHeader): Future[Result] = {
// returns Future.successful(Found("DummyUrltoRedirect"))
}
}
The deeperFunction is inherited from a trait and I don't want use the real one here because it's a unit test and so I want to use a matcher instead
val deeperMock = mock[Rainmaker]
val contextMock = mock[Context]
val controller = new Controller()(.....) // list of implicit arguments
"Controller" must {
"return something" in {
val request = FakeRequest("GET", "/something")
when(deeperMock.deeperFunction(anyObject)(anyObject)) thenReturn Future.successful(Found("DummyUrlToRedirect"))
val id = "id"
val result = controller.functionToTest(id).apply(request)
status(result) mustBe Ok
}
}
But when I run this, the line "val result = controller.functionToTest(id).apply(request)" still seems to call the real deeperFunction, not the fake one and therefore throws a null matcher at some point.
I also tried to use
when(controller.deeperFunction(anyObject)(anyObject)) thenReturn Future.successful(Found("DummyUrlToRedirect"))
instead, because the deeperFunction is inherited, but with the same result.
I tried to stick to theses instructions
ScalaTest+Play
dzone
but it seems I am still missing some basics/understanding. Thanks in advance.
I'm writing a Scala library to operate upon Spark DataFrames. I have a bunch of classes, each of which contain a function that operates upon the supplied DataFrame:
class Foo(){val func = SomeFunction(,,,)}
class Bar(){val func = SomeFunction(,,,)}
class Baz(){val func = SomeFunction(,,,)}
The user of my library passes a parameter operation: String to indicate class to instantiate, the value passed has to be the name of one of those classes hence I have code that looks something like this:
operation match {
case Foo => new Foo().SomeFunction
case Bar => new Bar().SomeFunction
case Baz => new Baz().SomeFunction
}
I'm a novice Scala developer but this seems rather like a clunky way of achieving this. I'm hoping there is a simpler way to instantiate the desired class based on the value of operation given that it will be the same as the name of the desired class.
The reason I want to do this is that I want external contributors to contribute their own classes and I want to make it at easy as possible for them to do that, I don't want them to have to know they also need to go and change a pattern match.
For
case class SomeFunction(s: String)
class Foo(){val func = SomeFunction("Foo#func")}
class Bar(){val func = SomeFunction("Bar#func")}
class Baz(){val func = SomeFunction("Baz#func")}
//...
reflection-based version of
def foo(operation: String) = operation match {
case "Foo" => new Foo().func
case "Bar" => new Bar().func
case "Baz" => new Baz().func
// ...
}
is
import scala.reflect.runtime.universe
import scala.reflect.runtime.universe._
def foo(operation: String): SomeFunction = {
val runtimeMirror = universe.runtimeMirror(getClass.getClassLoader)
val classSymbol = runtimeMirror.staticClass(operation)
val constructorSymbol = classSymbol.primaryConstructor.asMethod
val classMirror = runtimeMirror.reflectClass(classSymbol)
val classType = classSymbol.toType
val constructorMirror = classMirror.reflectConstructor(constructorSymbol)
val instance = constructorMirror()
val fieldSymbol = classType.decl(TermName("func")).asTerm
val instanceMirror = runtimeMirror.reflect(instance)
val fieldMirror = instanceMirror.reflectField(fieldSymbol)
fieldMirror.get.asInstanceOf[SomeFunction]
}
Testing:
foo("Foo") //SomeFunction(Foo#func)
foo("Bar") //SomeFunction(Bar#func)
foo("Baz") //SomeFunction(Baz#func)
I have a scala case class and object like below,
case class User(userId: Long, UserName: String, ts: Timestamp)
object User {
def getRdd(rdd: RDD[JsValue], type : String): RDD[User] = {
val rdd1: RDD[User] = rdd.map(doc => processEvent(doc))
.filter(event => event._1.equals(rddType)).map(event => {
User.get_class_obj(event)
})
rdd1
}
}
I want to call "getRdd" method of User Object from another object without creating instance of object/class. like below,
val object_name = "com.User"
val method_name = "getRdd"
I tried,
val no = Array(1, 2, 3, 4, 5,6,7,8,9,10)
val rdd = sc.parallelize(no)
Class.forName(object_name).getDeclaredMethod(method_name).invoke(rdd)
but fails with nosuchmethod error. I have gone through answers here but I don't want to create multiple instances every time. Is it possible to do it in one-liner.
Try with dollar sign
val object_name = "com.User$"
if object User is in package com.
From Java reflection point of view User is a class and User$ is its companion object.
You should also specify classes of arguments
Class.forName("com.User$").getDeclaredMethod("getRdd", classOf[RDD[_]], classOf[String])
I'm building an API, that takes in a variable path parameter, or dynamic part of the route, as the play documentation would specify it.
I would like to validate this as to give the client a proper response.
I have the following route setup
GET /:dynamic/all controller.method(dynamic: String)
The dynamic param for the method is used across the API, for multiple methods, so i would like to get some kind of global validation/whitelist of acceptable strings. (eg: "hello"/"hi" would be accepted, and "noooway" would not be accepted, and i would return a 404 not found as response.
I would preferably like my controller method to not contain any validation so that this would be true:
def method(dynamic: String): Action[AnyContent] = Action.async { _ =>
//I already know "dynamic" is valid here.
Future.successful(Ok(Json.toJson(Map("status" -> "OK"))))
}
Instead of: (excuse my javaisc-psuedo-code)
def method(dynamic: String): Action[AnyContent] = Action.async { _ =>
val valid = Helper.validate(dynamic)
if (!valid) return some result/response else
Future.successful(Ok(Json.toJson(Map("status" -> "OK"))))
}
Play allows you to do this by different ways.
1. PathBindable
You can implement a PathBindable[T] for any type T, so that your value extracted from the path of the request is not a simple String but a T.
If you are ready to change the type of dynamic (which would make sense, since it is not supposed to be just any string but a valid one), you could do the following:
case class Validated(str: String) {
assert(Helper.validate(str))
}
object Validated {
implicit val pathBindable = new PathBindable[Validated] {
val string = implicitly[PathBindable[String]]
override def bind(key: String, value: String): Either[String, Validated] =
string.bind(key, value). // bind as if it were a string
right.filter(Helper.validate).getOrElse(Left("Invalid input")). // filter using your validation function, and give error message
right.map(Validated(_)) // encapsulate in your new type
override def unbind(key: String, value: Validated): String =
string.unbind(key, value.str) //unbind as if it were a string
}
}
Note that you need to implement unbind for reverse routing (get a path for a given action call).
Now, you just need to replace String in your router and in your controller by your.package.Validated.
GET /:dynamic/all controller.method(dynamic: your.package.Validated)
NB: if you want to use the simple name of your class, you need to import it in your build.sbt:
(project in file(".").
enablePlugins(PlayScala).
settings(routesImport += "your.package.Validated")
2. Action Composition
You can also implement an action filter to be used whenever your input needs to be validated:
case class ValidatedAction(input: String) extends ActionFilter[Request] {
override protected def filter[A](request: Request[A]): Future[Option[Result]] = Future.successful{
if (Helper.validate(input)) None else Some(BadRequest("Invalid input"))
}
}
def method(dynamic: String) = (Action andThen ValidatedAction(dynamic)).async {
Future.successful(Ok)
}
The code inside the async block will be executed only if the filter method returns None, otherwise, it will return the specified Result (here, BadRequest("Invalid input").
I'm using scala and slick here, and I have a baserepository which is responsible for doing the basic crud of my classes.
For a design decision, we do have updatedTime and createdTime columns all handled by the application, and not by triggers in database. Both of this fields are joda DataTime instances.
Those fields are defined in two traits called HasUpdatedAt, and HasCreatedAt, for the tables
trait HasCreatedAt {
val createdAt: Option[DateTime]
}
case class User(name:String,createdAt:Option[DateTime] = None) extends HasCreatedAt
I would like to know how can I use reflection to call the user copy method, to update the createdAt value during the database insertion method.
Edit after #vptron and #kevin-wright comments
I have a repo like this
trait BaseRepo[ID, R] {
def insert(r: R)(implicit session: Session): ID
}
I want to implement the insert just once, and there I want to createdAt to be updated, that's why I'm not using the copy method, otherwise I need to implement it everywhere I use the createdAt column.
This question was answered here to help other with this kind of problem.
I end up using this code to execute the copy method of my case classes using scala reflection.
import reflect._
import scala.reflect.runtime.universe._
import scala.reflect.runtime._
class Empty
val mirror = universe.runtimeMirror(getClass.getClassLoader)
// paramName is the parameter that I want to replacte the value
// paramValue is the new parameter value
def updateParam[R : ClassTag](r: R, paramName: String, paramValue: Any): R = {
val instanceMirror = mirror.reflect(r)
val decl = instanceMirror.symbol.asType.toType
val members = decl.members.map(method => transformMethod(method, paramName, paramValue, instanceMirror)).filter {
case _: Empty => false
case _ => true
}.toArray.reverse
val copyMethod = decl.declaration(newTermName("copy")).asMethod
val copyMethodInstance = instanceMirror.reflectMethod(copyMethod)
copyMethodInstance(members: _*).asInstanceOf[R]
}
def transformMethod(method: Symbol, paramName: String, paramValue: Any, instanceMirror: InstanceMirror) = {
val term = method.asTerm
if (term.isAccessor) {
if (term.name.toString == paramName) {
paramValue
} else instanceMirror.reflectField(term).get
} else new Empty
}
With this I can execute the copy method of my case classes, replacing a determined field value.
As comments have said, don't change a val using reflection. Would you that with a java final variable? It makes your code do really unexpected things. If you need to change the value of a val, don't use a val, use a var.
trait HasCreatedAt {
var createdAt: Option[DateTime] = None
}
case class User(name:String) extends HasCreatedAt
Although having a var in a case class may bring some unexpected behavior e.g. copy would not work as expected. This may lead to preferring not using a case class for this.
Another approach would be to make the insert method return an updated copy of the case class, e.g.:
trait HasCreatedAt {
val createdAt: Option[DateTime]
def withCreatedAt(dt:DateTime):this.type
}
case class User(name:String,createdAt:Option[DateTime] = None) extends HasCreatedAt {
def withCreatedAt(dt:DateTime) = this.copy(createdAt = Some(dt))
}
trait BaseRepo[ID, R <: HasCreatedAt] {
def insert(r: R)(implicit session: Session): (ID, R) = {
val id = ???//insert into db
(id, r.withCreatedAt(??? /*now*/))
}
}
EDIT:
Since I didn't answer your original question and you may know what you are doing I am adding a way to do this.
import scala.reflect.runtime.universe._
val user = User("aaa", None)
val m = runtimeMirror(getClass.getClassLoader)
val im = m.reflect(user)
val decl = im.symbol.asType.toType.declaration("createdAt":TermName).asTerm
val fm = im.reflectField(decl)
fm.set(??? /*now*/)
But again, please don't do this. Read this stackoveflow answer to get some insight into what it can cause (vals map to final fields).