xerial.lens.MethodCallBuilder.scala Maven / Gradle / Ivy

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Lens for mapping between objects and structured data (XML, JSON, Silk, etc.)

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/*
 * Copyright 2012 Taro L. Saito
 *
 * 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 xerial.lens

import collection.mutable
import mutable.ArrayBuffer
import xerial.core.log.Logger
import xerial.core.util.CName


//--------------------------------------
//
// MethodCallBuilder.scala
// Since: 2012/03/27 16:43
//
//--------------------------------------

/**
 * Builds method call arguments
 * @author leo
 */
class MethodCallBuilder(m:ObjectMethod, owner:AnyRef) extends StandardBuilder[MethodParameter] with Logger {

  // Find the default arguments of the method
  protected def defaultValues = (for(p <- m.params; v <- findDefaultValue(p.name)) yield p.name -> v).toMap

  protected def findParameter(name:String) : Option[MethodParameter] = {
    val cname = CName(name)
    m.params.find(p => CName(p.name) == cname)
  }

  private def findDefaultValue(name:String) : Option[Any] = {
    findParameter(name).flatMap{ p =>
      try {
        val methodName = "%s$default$%d".format(m.name, p.index + 1)
        val dm = owner.getClass.getMethod(methodName)
        Some(dm.invoke(owner))
      }
      catch {
        case _ : Throwable => None
      }
    }
  }


  def execute : Any = {
    trace(s"holder: $holder")
    val args = for(p <- m.params) yield {
      (get(p.name) getOrElse TypeUtil.zero(p.rawType, p.valueType)).asInstanceOf[AnyRef]
    }
    trace { "args: " + args.mkString(", ") }
    if(args.isEmpty)
      m.jMethod.invoke(owner)
    else
      m.jMethod.invoke(owner, args:_*)
  }

}