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A library for extracting object structure surface
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package wvlet.surface.reflect
import java.util.Locale
import wvlet.log.LogSupport
import wvlet.surface.reflect.ReflectTypeUtil._
import wvlet.surface._
import scala.collection.JavaConverters._
import scala.collection.mutable
import scala.collection.mutable.ArrayBuffer
import wvlet.surface.CanonicalNameFormatter._
import scala.language.existentials
//--------------------------------------
//
// ObjectBuilder.scala
// Since: 2012/01/25 12:41
//
//--------------------------------------
/**
*
*
*/
object ObjectBuilder extends LogSupport {
def apply(s: Surface): ObjectBuilder = {
new SimpleObjectBuilder(s)
}
def fromObject[A](surface: Surface, obj: A): ObjectBuilder = {
val b = new SimpleObjectBuilder(surface)
for (p <- surface.params) {
b.set(p.name, p.get(obj))
}
b
}
sealed trait BuilderElement
case class Holder(holder: ObjectBuilder) extends BuilderElement
case class Value(value: Any) extends BuilderElement
case class ArrayHolder(holder: mutable.ArrayBuffer[Any]) extends BuilderElement
}
trait GenericBuilder {
def set(path: String, value: Any): Unit = set(Path(path), value)
def set(path: Path, value: Any): Unit
def get(name: String): Option[Any]
}
/**
* Generic object builder
*
* @author leo
*/
trait ObjectBuilder extends GenericBuilder {
def build: Any
}
trait StandardBuilder extends GenericBuilder with LogSupport {
import ObjectBuilder._
protected val holder = collection.mutable.Map.empty[String, BuilderElement]
protected def findParameter(name: String): Option[Parameter]
protected def getParameterTypeOf(name: String) = findParameter(name).get
protected def defaultValues: collection.immutable.Map[String, Any]
// set the default values of the object
for ((name, value) <- defaultValues) {
val v: BuilderElement = findParameter(name).map {
case p if canBuildFromBuffer(p.surface) => Value(value)
case p if canBuildFromStringValue(p.surface) => Value(value)
case p => {
// nested object
// TODO handling of recursive objects
val b = new SimpleObjectBuilder(p.surface)
for (x <- p.surface.params) {
b.set(x.name.canonicalName, x.get(value))
}
Holder(b)
}
} getOrElse Value(value)
holder += name -> v
}
private def canBuildFromStringValue(t: Surface): Boolean = {
t match {
case t if canBuildFromString(t) => true
case o: OptionSurface => canBuildFromStringValue(o.elementSurface)
case _ => false
}
}
private def getArrayHolder(name: String): ArrayHolder = {
// Clear the default value holder if exists
holder.get(name) match {
case Some(Value(v)) =>
// remove the default value
holder.remove(name)
case _ => // do nothing
}
holder.getOrElseUpdate(name, ArrayHolder(new ArrayBuffer[Any])).asInstanceOf[ArrayHolder]
}
def set(path: Path, value: Any): Unit = {
if (path.isEmpty) {
// do nothing
} else {
val name = path.head.canonicalName
val p = findParameter(name)
if (p.isEmpty) {
error(s"no parameter is found for path $path")
} else {
trace(s"set path $path : $value")
if (path.isLeaf) {
val targetType = p.get.surface
trace(
s"update value holder name:$name, valueType:$targetType (isArray:${isArray(targetType)}) with value:$value (${value.getClass})")
if (canBuildFromBuffer(targetType)) {
val arr = getArrayHolder(name)
targetType.typeArgs.length match {
case 1 =>
// Append array elements to the buffer
val elementType = targetType.typeArgs(0)
val lst = value match {
case a if isArray(value.getClass) => a.asInstanceOf[Array[_]].toIndexedSeq
case a if isJavaColleciton(value.getClass) =>
a.asInstanceOf[java.util.Collection[_]].asScala.toIndexedSeq
case s if isSeq(value.getClass) => s.asInstanceOf[Seq[_]]
case other =>
Seq(other)
}
lst
.flatMap { x =>
TypeConverter.convert(x, elementType)
}
.foreach { arr.holder += _ }
case 2 =>
// Append map elements to the buffer
val lst = value match {
case m if isJavaMap(value.getClass) => m.asInstanceOf[java.util.Map[_, _]].asScala.toMap
case m if isMap(m.getClass) => m.asInstanceOf[Map[_, _]]
case other => Seq(other)
}
val keyType = targetType.typeArgs(0)
val valueType = targetType.typeArgs(1)
val tupleSurface = TupleSurface(classOf[Tuple2[_, _]], Seq(keyType, valueType))
lst
.flatMap { x =>
TypeConverter.convert(x, tupleSurface)
}
.foreach { arr.holder += _ }
case other =>
error(s"Cannot convert ${value} to ${targetType}")
}
} else if (canBuildFromStringValue(targetType)) {
TypeConverter.convert(value, targetType).map { v =>
holder += name -> Value(v)
}
} else {
error(s"failed to set $value to path $path")
}
} else {
// nested object
val paramName = path.head.canonicalName
val h = holder.getOrElseUpdate(paramName, Holder(ObjectBuilder(p.get.surface)))
h match {
case Holder(b) => b.set(path.tailPath, value)
case other =>
// overwrite the existing holder
throw new IllegalStateException("invalid path:%s, value:%s, holder:%s".format(path, value, other))
}
}
}
}
}
def get(name: String): Option[Any] = {
val paramName = name.canonicalName
holder.get(paramName) flatMap {
case Holder(h) => Some(h.build)
case Value(v) => Some(v)
case ArrayHolder(h) => {
val p = getParameterTypeOf(paramName)
debug(s"convert array holder:$h into $p")
TypeConverter.convert(h, p.surface)
}
}
}
}
class SimpleObjectBuilder(surface: Surface) extends ObjectBuilder with StandardBuilder with LogSupport {
require(surface.objectFactory.isDefined, s"No object factory is found for ${surface}")
import ObjectBuilder._
protected def findParameter(name: String) = {
assert(surface != null)
val cname = name.canonicalName
surface.params.find(_.name.canonicalName == cname)
}
protected def defaultValues = {
// collect default values of the object
val prop = Map.newBuilder[String, Any]
// get the default values of the constructor
for (p <- surface.params; v <- p.getDefaultValue) {
trace(s"set default parameter $p to $v")
prop += p.name.canonicalName -> v
}
val r = prop.result
trace(s"surface ${surface}. values to set: $r")
r
}
def build: Any = {
trace(s"holder contents: $holder")
val factory = surface.objectFactory.get
val args = for (p <- surface.params) yield {
get(p.name.canonicalName).getOrElse(Zero.zeroOf(p.surface))
}
trace(s"build: ${surface} from args:${args.mkString(", ")}")
factory.newInstance(args)
}
}