MapTransformer

The problem we're trying to solve: converting maps to classes in Scala is not very easy to do in a functional way, and it gets even harder if you have a class with >22 fields (so can't use case classes).

For a discussion about this on Stack Overflow, see: http://stackoverflow.com/questions/4290955/instantiating-a-case-class-from-a-list-of-parameters

The idea is to use Java Reflection with a big ol' TransformMap:

("key in map" -> Tuple2(transformFunc, "field in class"), "another key" -> Tuple2(transformFunc, "field in class"), "a third key" -> Tuple2(transformFunc, "field in class"))

And then there would be an iteration through the source map which looks up the key in the TransformMap and then applies the transformFunc using Java Reflection, storing the answer in the class's specified field.

If I can get this working, then the next step is to generate a "results" map which contains the results of each transformFunc. Each transformFunc should either return a ValidationNel[String, Unit], or should be promoted (via an implicit) to the same.

Having this should allow me to do something like: resultsMap.foldLeft(Unit.success, |@|) to roll up any validation errors into one final ValidatioNel.

If I can get all that working, then the final step is to support transformFuncs which set multiple fields. To avoid the complexity spiralling, it would probably be simplest if any transformFunc that wanted to return multiple values returned a TupleN, and then we use the same TupleN for the target fields. Maybe there will be an implicit to convert "raw" target fields into Tuple1s.

Okay, let's start...

Linear Supertypes

AnyRef, Any

Type Members

type Field = String
type Key = String
type SettersMap = Map[Key, Method]
type SourceMap = Map[Key, Value]
type TransformFunc = (Key, Value) ⇒ Validation[String, _]
type TransformMap = Map[Key, Tuple2[TransformFunc, _]]
class TransformableClass[T] extends AnyRef

A pimped object, now transformable by using the transform method.
type Value = String

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
def generate[T <: AnyRef](sourceMap: SourceMap, transformMap: TransformMap)(implicit m: Manifest[T]): Validated[T]

A factory to generate a new object using a TransformMap.
A factory to generate a new object using a TransformMap.
sourceMap
Contains the source data to apply to the obj
transformMap
Determines how the source data should be transformed before storing in the obj
returns
a ValidationNel containing either a Nel of error Strings, or the new object
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
implicit def makeTransformable[T <: AnyRef](obj: T)(implicit m: Manifest[T]): TransformableClass[T]

An implicit conversion to take any Object and make it Transformable.
An implicit conversion to take any Object and make it Transformable.
obj
Any Object
returns
the new Transformable class, with manifest attached
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Related Doc: package utils

object MapTransformer

Type Members

type Field = String

type Key = String

type SettersMap = Map[Key, Method]

type SourceMap = Map[Key, Value]

type TransformFunc = (Key, Value) ⇒ Validation[String, _]

type TransformMap = Map[Key, Tuple2[TransformFunc, _]]

class TransformableClass[T] extends AnyRef

type Value = String

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

def generate[T <: AnyRef](sourceMap: SourceMap, transformMap: TransformMap)(implicit m: Manifest[T]): Validated[T]

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

implicit def makeTransformable[T <: AnyRef](obj: T)(implicit m: Manifest[T]): TransformableClass[T]

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from AnyRef

Inherited from Any

Ungrouped