/* __ *\ ** ________ ___ / / ___ Scala API ** ** / __/ __// _ | / / / _ | (c) 2003-2011, LAMP/EPFL ** ** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** ** /____/\___/_/ |_/____/_/ | | ** ** |/ ** \* */ package scala.xml import Utility.sbToString import annotation.tailrec import scala.collection.Iterator /** * Copyright 2008 Google Inc. All Rights Reserved. * @author Burak Emir <bqe@google.com> */ object MetaData { /** * appends all attributes from new_tail to attribs, without attempting to detect * or remove duplicates. The method guarantees that all attributes from attribs come before * the attributes in new_tail, but does not guarantee to preserve the relative order of attribs. * Duplicates can be removed with normalize. */ @tailrec def concatenate(attribs: MetaData, new_tail: MetaData): MetaData = if (attribs eq Null) new_tail else concatenate(attribs.next, attribs copy new_tail) /** * returns normalized MetaData, with all duplicates removed and namespace prefixes resolved to * namespace URIs via the given scope. */ def normalize(attribs: MetaData, scope: NamespaceBinding): MetaData = { def iterate(md: MetaData, normalized_attribs: MetaData, set: Set[String]): MetaData = { lazy val key = getUniversalKey(md, scope) if (md eq Null) normalized_attribs else if (set(key)) iterate(md.next, normalized_attribs, set) else iterate(md.next, md copy normalized_attribs, set + key) } iterate(attribs, Null, Set()) } /** * returns key if md is unprefixed, pre+key is md is prefixed */ def getUniversalKey(attrib: MetaData, scope: NamespaceBinding) = attrib match { case prefixed: PrefixedAttribute => scope.getURI(prefixed.pre) + prefixed.key case unprefixed: UnprefixedAttribute => unprefixed.key } /** * returns MetaData with attributes updated from given MetaData */ def update(attribs: MetaData, scope: NamespaceBinding, updates: MetaData): MetaData = normalize(concatenate(updates, attribs), scope) } /** <p> * This class represents an attribute and at the same time a linked list of attributes. * Every instance of this class is either an instance of UnprefixedAttribute <code>key,value</code> * or an instance of PrefixedAttribute <code>namespace_prefix,key,value</code> or Null, the empty * attribute list. Namespace URIs are obtained by using the namespace scope of the element owning * this attribute (see <code>getNamespace</code>) * </p> * * Copyright 2008 Google Inc. All Rights Reserved. * @author Burak Emir <bqe@google.com> */ abstract class MetaData extends Iterable[MetaData] with Equality with Serializable { /** Updates this MetaData with the MetaData given as argument. All attributes that occur in updates * are part of the resulting MetaData. If an attribute occurs in both this instance and * updates, only the one in updates is part of the result (avoiding duplicates). For prefixed * attributes, namespaces are resolved using the given scope, which defaults to TopScope. * * @param updates MetaData with new and updated attributes * @return a new MetaData instance that contains old, new and updated attributes */ def append(updates: MetaData, scope: NamespaceBinding = TopScope): MetaData = MetaData.update(this, scope, updates) /** * Gets value of unqualified (unprefixed) attribute with given key, null if not found * * @param key * @return value as Seq[Node] if key is found, null otherwise */ def apply(key: String): Seq[Node] /** convenience method, same as <code>apply(namespace, owner.scope, key)</code>. * * @param namespace_uri namespace uri of key * @param owner the element owning this attribute list * @param key the attribute key * @return ... */ final def apply(namespace_uri: String, owner: Node, key: String): Seq[Node] = apply(namespace_uri, owner.scope, key) /** * Gets value of prefixed attribute with given key and namespace, null if not found * * @param namespace_uri namespace uri of key * @param scp a namespace scp (usually of the element owning this attribute list) * @param key to be looked fore * @return value as Seq[Node] if key is found, null otherwise */ def apply(namespace_uri:String, scp:NamespaceBinding, k:String): Seq[Node] /** returns a copy of this MetaData item with next field set to argument. * * @param next ... * @return ... */ def copy(next: MetaData): MetaData /** if owner is the element of this metadata item, returns namespace */ def getNamespace(owner: Node): String def hasNext = (Null != next) def length: Int = length(0) def length(i: Int): Int = next.length(i + 1) def isPrefixed: Boolean override def canEqual(other: Any) = other match { case _: MetaData => true case _ => false } override def strict_==(other: Equality) = other match { case m: MetaData => this.asAttrMap == m.asAttrMap case _ => false } def basisForHashCode: Seq[Any] = List(this.asAttrMap) /** Returns an iterator on attributes */ def iterator: Iterator[MetaData] = Iterator.single(this) ++ next.iterator override def size: Int = 1 + iterator.length /** filters this sequence of meta data */ override def filter(f: MetaData => Boolean): MetaData = if (f(this)) copy(next filter f) else next filter f /** returns key of this MetaData item */ def key: String /** returns value of this MetaData item */ def value: Seq[Node] /** Returns a String containing "prefix:key" if the first key is * prefixed, and "key" otherwise. */ def prefixedKey = this match { case x: Attribute if x.isPrefixed => x.pre + ":" + key case _ => key } /** Returns a Map containing the attributes stored as key/value pairs. */ def asAttrMap: Map[String, String] = iterator map (x => (x.prefixedKey, x.value.text)) toMap /** returns Null or the next MetaData item */ def next: MetaData /** * Gets value of unqualified (unprefixed) attribute with given key, None if not found * * @param key * @return value in Some(Seq[Node]) if key is found, None otherwise */ final def get(key: String): Option[Seq[Node]] = Option(apply(key)) /** same as get(uri, owner.scope, key) */ final def get(uri: String, owner: Node, key: String): Option[Seq[Node]] = get(uri, owner.scope, key) /** gets value of qualified (prefixed) attribute with given key. * * @param uri namespace of key * @param scope a namespace scp (usually of the element owning this attribute list) * @param key to be looked fore * @return value as Some[Seq[Node]] if key is found, None otherwise */ final def get(uri: String, scope: NamespaceBinding, key: String): Option[Seq[Node]] = Option(apply(uri, scope, key)) def toString1(): String = sbToString(toString1) // appends string representations of single attribute to StringBuilder def toString1(sb: StringBuilder): Unit override def toString(): String = sbToString(buildString) def buildString(sb: StringBuilder): StringBuilder = { sb.append(' ') toString1(sb) next.buildString(sb) } /** * @param scope ... * @return <code>true</code> iff ... */ def wellformed(scope: NamespaceBinding): Boolean /** * @param key ... * @return ... */ def remove(key: String): MetaData /** * @param namespace ... * @param scope ... * @param key ... * @return ... */ def remove(namespace: String, scope: NamespaceBinding, key: String): MetaData /** * @param namespace ... * @param owner ... * @param key ... * @return ... */ final def remove(namespace: String, owner: Node, key: String): MetaData = remove(namespace, owner.scope, key) }