platform/typerendering.scala/src/main/scala/org/apache/clerezza/platform/typerendering/scala/XmlResult.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.clerezza.platform.typerendering.scala

import java.io.OutputStream
import java.io.OutputStreamWriter
import java.io.PrintWriter
import java.net.URI
import javax.ws.rs.core.HttpHeaders
import javax.ws.rs.core.MediaType
import scala.xml._
import org.apache.clerezza.platform.typerendering._
import org.apache.clerezza.platform.typerendering.TypeRenderlet.RequestProperties
import org.apache.clerezza.rdf.utils.GraphNode
import org.apache.clerezza.rdf.ontologies._
import org.apache.clerezza.rdf.core._
import org.apache.clerezza.rdf.utils._
import org.apache.clerezza.rdf.scala.utils.Preamble._
import java.nio.charset.Charset
import java.security.{PrivilegedAction, AccessController}
import org.apache.clerezza.commons.rdf.IRI
import org.osgi.framework.{BundleContext, ServiceReference}
import org.apache.clerezza.rdf.scala.utils.RichGraphNode

/**
 * PageRenderlet.renderedPage returns an instance of this class, implementing
 * the content method to produce an XML Element suitable as response to the
 * request yielding to the arguments passed to the constructor.
 */
abstract class XmlResult(arguments: XmlResult.Arguments) {

  private val UTF8: Charset = Charset.forName("utf-8")
  
  val XmlResult.Arguments(
          res: GraphNode,
          context: GraphNode,
          sharedRenderingValues: java.util.Map[String, Object],
          renderer: CallbackRenderer,
          modeOption: Option[String],
          mediaType: MediaType,
          requestProperties: RequestProperties,
          os: OutputStream) = arguments;
  val mode = modeOption match {
    case Some(x) => x
    case None => null
  }

  val uriInfo = requestProperties.getUriInfo
  val requestHeaders = requestProperties.getRequestHeaders
  val responseHeaders = requestProperties.getResponseHeaders

  def render(resource: GraphNode): Seq[Node] = {
    modeOption match {
      case Some(m) => render(resource, m)
      case None => render(resource, "naked")
    }
  }

  def render(resource: GraphNode, mode: String) = {
    val baos = new java.io.ByteArrayOutputStream
    renderer.render(resource, context, mode, baos)
    Unparsed(new String(baos.toByteArray, UTF8))
  }

  /**
   * renders the specified resource without using the base-graph from resource
   * rendered by the caller but getting a new context using the GraphNodeProvider
   */
  def render(resource: IRI): Seq[Node] = {
    modeOption match {
      case Some(m) => render(resource, m)
      case None => render(resource, "naked")
    }
  }

  /**
   * renders the specified resource without using the base-graph from resource
   * rendered by the caller but getting a new context using the GraphNodeProvider
   */
  def render(resource: IRI, mode: String) = {
    val baos = new java.io.ByteArrayOutputStream
    renderer.render(resource, context, mode, baos)
    Unparsed(new String(baos.toByteArray, UTF8))
  }

  /**
   * This is an object that allows one to use some nice shortcuts in scala based subclasses
   * - $variable will get the value of the sharedRenderingValues hash
   * - $variable = value allows one to update the sharedRenderingValues hash
   * - $[ClassName] allows to access an osgi service annotated to be a WebRenderingService
   */
  object dollar {
    def apply(key: String) = sharedRenderingValues.get(key)

    def update(key: String, value: Object) = sharedRenderingValues.put(key, value)

    def apply[T](implicit m: Manifest[T]): T = {
      val clazz = m.erasure.asInstanceOf[Class[T]]
      requestProperties.getRenderingService(clazz)
    }
  }

    /** no idea why, but since scala 2.10 it doesn't work if the object 
    * is called $ directly */
    val $ = dollar
   
  def ifx[T](con: => Boolean)(f: => T): T = {
    if (con) f else null.asInstanceOf[T]
  }

  val resultDocModifier = org.apache.clerezza.platform.typerendering.ResultDocModifier.getInstance();

  val out = new PrintWriter(new OutputStreamWriter(os,UTF8))

  out.print(
    content match {
      case s: Seq[_] => s.mkString
      case o => o.toString
    }
  )
  out.flush()

  /**
   * This is the main method/variable that needs to be implemented by subclasses
   */
  def content: AnyRef;


}

object XmlResult {

  /**
   * Class to encapsulate information sent to the rendering engine.
   *
   * @param res  RDF resource to be rendered with the template.
   * @param context  RDF resource providing a rendering context.
   * @param sharedRenderingValues  a map that can be used for sharing values
   * across the different Renderlets involved in a rendering process
   * @param callbackRenderer  renderer for call backs.
   * @param renderingSpecification  the rendering specification
   * @param modeOption the mode this Renderlet was invoked with, this is mainly used
   * so that the callbackRenderer can be claeed inheriting the mode.
   * @param mediaType  the media type this media produces (a part of)
   * @param requestProperties properties of the http request, may be null
   * @param os  where the output will be written to.
   */
  case class Arguments(res: GraphNode,
          context: GraphNode,
          sharedRenderingValues: java.util.Map[String, Object],
          renderer: CallbackRenderer,
          modeOption: Option[String],
          mediaType: MediaType,
          requestProperties: RequestProperties,
          os: OutputStream);
}