Scala example source code file (PrefixedAttribute.scala)

This example Scala source code file (PrefixedAttribute.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

attribute, metadata, metadata, namespacebinding, node, prefixedattribute, prefixedattribute, seq, seq, string, string, text, unsupportedoperationexception

The Scala PrefixedAttribute.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */


package scala.xml

/** prefixed attributes always have a non-null namespace.
 *
 *  @param pre   ...
 *  @param key   ...
 *  @param value the attribute value, which may not be null
 *  @param next  ...
 */
class PrefixedAttribute(
  val pre: String,
  val key: String,
  val value: Seq[Node],
  val next: MetaData)
extends Attribute
{
  if (value eq null)
    throw new UnsupportedOperationException("value is null")

  /** same as this(key, Utility.parseAttributeValue(value), next) */
  def this(pre: String, key: String, value: String, next: MetaData) = 
    this(pre, key, Text(value), next)

  /** Returns a copy of this unprefixed attribute with the given
   *  next field.
   */
  def copy(next: MetaData) = 
    new PrefixedAttribute(pre, key, value, next)

  def getNamespace(owner: Node) = 
    owner.getNamespace(pre)

  /** forwards the call to next (because caller looks for unprefixed attribute */
  def apply(key: String): Seq[Node] = next(key)

  /** gets attribute value of qualified (prefixed) attribute with given key 
   */
  def apply(namespace: String, scope: NamespaceBinding, key: String): Seq[Node] = {
    if (key == this.key && scope.getURI(pre) == namespace)
      value
    else 
      next(namespace, scope, key)
  }
}

object PrefixedAttribute {
  def unapply(x: PrefixedAttribute) = Some(x.pre, x.key, x.value, x.next)
}