CODEWITHSUNDEEP
scalalifttraits
Shafique Jamal
Shafique Jamal

Reputation: 1688

How do I write a trait that can mix in overrides of CRUDify members (that need to access the User model) in Mapper models?

I am trying to eliminate some redundancy in the models in my lift application that uses Mapper and CRUDify (see below for the models). I repeatedly override some class members in the object definition as follows:

override def showAllMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))
override def createMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))

I would like to make a trait that takes care of this, so that I can mix in the trait as follows:

object Test1 extends Test1 with LongKeyedMetaMapper[Test1] with CRUDify[Long, Test1] with MyNewTrait {

where MyNewTrait would be defined something like:

trait MyNewTrait {
  override def showAllMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))
  override def createMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))  
}

I guess this trait would have to have access to the User model. Can anyone advise on how to write the trait? As written above, the trait is incomplete. I can't figure out what to put after trait MyNewTrait

Thanks,

/* ********************************************************************************************* */
object Test1 extends Test1 with LongKeyedMetaMapper[Test1] with CRUDify[Long, Test1] {
  override def dbTableName = "test1"
  override def fieldOrder = List(c1, c2, c3)
  override def showAllMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))
  override def createMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))
}
class Test1 extends LongKeyedMapper[Test1] with IdPK {
  def getSingleton = Test1 
  object c1 extends MappedString(this, 50)
  object c2 extends MappedString(this, 50)
  object c3 extends MappedString(this, 50)
}
/* ********************************************************************************************* */
object Test1 extends Test1 with LongKeyedMetaMapper[Test1] with CRUDify[Long, Test1] {
  override def dbTableName = "test2"
  override def fieldOrder = List(c1, c2, c3)
  override def showAllMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))
  override def createMenuLocParams: List[Loc.AnyLocParam] = List(If(User.loggedIn_? _, "Not logged in"))
}
class Test1 extends LongKeyedMapper[Test1] with IdPK {
  def getSingleton = Test1 
  object c1 extends MappedString(this, 50)
  object c2 extends MappedString(this, 50)
  object c3 extends MappedString(this, 50)
}

Upvotes: 1

Views: 45

Answers (1)

yǝsʞǝla
yǝsʞǝla

Reputation: 16412

I don't have a project handy to check the code but this should work:

trait MyNewTrait[KeyType, CrudType <: KeyedMapper[KeyType, CrudType]]
extends CRUDify[KeyType, CrudType] {
  self: CrudType with KeyedMetaMapper[KeyType, CrudType] =>

    override def showAllMenuLocParams: List[Loc.AnyLocParam] =
      List(If(User.loggedIn_? _, "Not logged in"))

    override def createMenuLocParams: List[Loc.AnyLocParam] =
      List(If(User.loggedIn_? _, "Not logged in"))  
}

You can mix it instead of CRUDify trait afterwards.

Since you using Long key type you can also extend LongCRUDify in a similar way having one type parameter less.

Upvotes: 3

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