| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| |
| |
| package org.apache.xpath.domapi; |
| |
| import javax.xml.transform.TransformerException; |
| |
| import org.apache.xpath.XPath; |
| import org.apache.xpath.objects.XObject; |
| import org.apache.xpath.res.XPATHErrorResources; |
| import org.apache.xpath.res.XPATHMessages; |
| import org.w3c.dom.DOMException; |
| import org.w3c.dom.Node; |
| import org.w3c.dom.NodeList; |
| import org.w3c.dom.events.Event; |
| import org.w3c.dom.events.EventListener; |
| import org.w3c.dom.events.EventTarget; |
| import org.w3c.dom.traversal.NodeIterator; |
| import org.w3c.dom.xpath.XPathException; |
| import org.w3c.dom.xpath.XPathResult; |
| |
| /** |
| * |
| * The class provides an implementation XPathResult according |
| * to the DOM L3 XPath Specification, Working Group Note 26 February 2004. |
| * |
| * <p>See also the <a href='http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226'>Document Object Model (DOM) Level 3 XPath Specification</a>.</p> |
| * |
| * <p>The <code>XPathResult</code> interface represents the result of the |
| * evaluation of an XPath expression within the context of a particular |
| * node. Since evaluation of an XPath expression can result in various |
| * result types, this object makes it possible to discover and manipulate |
| * the type and value of the result.</p> |
| * |
| * <p>This implementation wraps an <code>XObject</code>. |
| * |
| * @see org.apache.xpath.objects.XObject |
| * @see org.w3c.dom.xpath.XPathResult |
| * |
| * @xsl.usage internal |
| */ |
| class XPathResultImpl implements XPathResult, EventListener { |
| |
| /** |
| * The wrapped XObject |
| */ |
| final private XObject m_resultObj; |
| |
| /** |
| * The xpath object that wraps the expression used for this result. |
| */ |
| final private XPath m_xpath; |
| |
| /** |
| * This the type specified by the user during construction. Typically |
| * the constructor will be called by org.apache.xpath.XPath.evaluate(). |
| */ |
| final private short m_resultType; |
| |
| private boolean m_isInvalidIteratorState = false; |
| |
| /** |
| * Only used to attach a mutation event handler when specified |
| * type is an iterator type. |
| */ |
| final private Node m_contextNode; |
| |
| /** |
| * The iterator, if this is an iterator type. |
| */ |
| private NodeIterator m_iterator = null;; |
| |
| /** |
| * The list, if this is a snapshot type. |
| */ |
| private NodeList m_list = null; |
| |
| |
| /** |
| * Constructor for XPathResultImpl. |
| * |
| * For internal use only. |
| */ |
| XPathResultImpl(short type, XObject result, Node contextNode, XPath xpath) { |
| // Check that the type is valid |
| if (!isValidType(type)) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_INVALID_XPATH_TYPE, new Object[] {new Integer(type)}); |
| throw new XPathException(XPathException.TYPE_ERR,fmsg); // Invalid XPath type argument: {0} |
| } |
| |
| // Result object should never be null! |
| if (null == result) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_EMPTY_XPATH_RESULT, null); |
| throw new XPathException(XPathException.INVALID_EXPRESSION_ERR,fmsg); // Empty XPath result object |
| } |
| |
| this.m_resultObj = result; |
| this.m_contextNode = contextNode; |
| this.m_xpath = xpath; |
| |
| // If specified result was ANY_TYPE, determine XObject type |
| if (type == ANY_TYPE) { |
| this.m_resultType = getTypeFromXObject(result); |
| } else { |
| this.m_resultType = type; |
| } |
| |
| // If the context node supports DOM Events and the type is one of the iterator |
| // types register this result as an event listener |
| if (((m_resultType == XPathResult.ORDERED_NODE_ITERATOR_TYPE) || |
| (m_resultType == XPathResult.UNORDERED_NODE_ITERATOR_TYPE))) { |
| addEventListener(); |
| |
| }// else can we handle iterator types if contextNode doesn't support EventTarget?? |
| |
| // If this is an iterator type get the iterator |
| if ((m_resultType == ORDERED_NODE_ITERATOR_TYPE) || |
| (m_resultType == UNORDERED_NODE_ITERATOR_TYPE) || |
| (m_resultType == ANY_UNORDERED_NODE_TYPE) || |
| (m_resultType == FIRST_ORDERED_NODE_TYPE)) { |
| |
| try { |
| m_iterator = m_resultObj.nodeset(); |
| } catch (TransformerException te) { |
| // probably not a node type |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_INCOMPATIBLE_TYPES, new Object[] {m_xpath.getPatternString(), getTypeString(getTypeFromXObject(m_resultObj)),getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR, fmsg); // "The XPathResult of XPath expression {0} has an XPathResultType of {1} which cannot be coerced into the specified XPathResultType of {2}."}, |
| } |
| |
| // If user requested ordered nodeset and result is unordered |
| // need to sort...TODO |
| // if ((m_resultType == ORDERED_NODE_ITERATOR_TYPE) && |
| // (!(((DTMNodeIterator)m_iterator).getDTMIterator().isDocOrdered()))) { |
| // |
| // } |
| |
| // If it's a snapshot type, get the nodelist |
| } else if ((m_resultType == UNORDERED_NODE_SNAPSHOT_TYPE) || |
| (m_resultType == ORDERED_NODE_SNAPSHOT_TYPE)) { |
| try { |
| m_list = m_resultObj.nodelist(); |
| } catch (TransformerException te) { |
| // probably not a node type |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_INCOMPATIBLE_TYPES, new Object[] {m_xpath.getPatternString(), getTypeString(getTypeFromXObject(m_resultObj)),getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR, fmsg); // "The XPathResult of XPath expression {0} has an XPathResultType of {1} which cannot be coerced into the specified XPathResultType of {2}."}, |
| } |
| } |
| } |
| |
| /** |
| * @see org.w3c.dom.xpath.XPathResult#getResultType() |
| */ |
| public short getResultType() { |
| return m_resultType; |
| } |
| |
| /** |
| * The value of this number result. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>NUMBER_TYPE</code>. |
| * @see org.w3c.dom.xpath.XPathResult#getNumberValue() |
| */ |
| public double getNumberValue() throws XPathException { |
| if (getResultType() != NUMBER_TYPE) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_CANT_CONVERT_XPATHRESULTTYPE_TO_NUMBER, new Object[] {m_xpath.getPatternString(), getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR,fmsg); |
| // "The XPathResult of XPath expression {0} has an XPathResultType of {1} which cannot be converted to a number" |
| } else { |
| try { |
| return m_resultObj.num(); |
| } catch (Exception e) { |
| // Type check above should prevent this exception from occurring. |
| throw new XPathException(XPathException.TYPE_ERR,e.getMessage()); |
| } |
| } |
| } |
| |
| /** |
| * The value of this string result. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>STRING_TYPE</code>. |
| * |
| * @see org.w3c.dom.xpath.XPathResult#getStringValue() |
| */ |
| public String getStringValue() throws XPathException { |
| if (getResultType() != STRING_TYPE) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_CANT_CONVERT_TO_STRING, new Object[] {m_xpath.getPatternString(), m_resultObj.getTypeString()}); |
| throw new XPathException(XPathException.TYPE_ERR,fmsg); |
| // "The XPathResult of XPath expression {0} has an XPathResultType of {1} which cannot be converted to a string." |
| } else { |
| try { |
| return m_resultObj.str(); |
| } catch (Exception e) { |
| // Type check above should prevent this exception from occurring. |
| throw new XPathException(XPathException.TYPE_ERR,e.getMessage()); |
| } |
| } |
| } |
| |
| /** |
| * @see org.w3c.dom.xpath.XPathResult#getBooleanValue() |
| */ |
| public boolean getBooleanValue() throws XPathException { |
| if (getResultType() != BOOLEAN_TYPE) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_CANT_CONVERT_TO_BOOLEAN, new Object[] {m_xpath.getPatternString(), getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR,fmsg); |
| // "The XPathResult of XPath expression {0} has an XPathResultType of {1} which cannot be converted to a boolean." |
| } else { |
| try { |
| return m_resultObj.bool(); |
| } catch (TransformerException e) { |
| // Type check above should prevent this exception from occurring. |
| throw new XPathException(XPathException.TYPE_ERR,e.getMessage()); |
| } |
| } |
| } |
| |
| /** |
| * The value of this single node result, which may be <code>null</code>. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>ANY_UNORDERED_NODE_TYPE</code> or |
| * <code>FIRST_ORDERED_NODE_TYPE</code>. |
| * |
| * @see org.w3c.dom.xpath.XPathResult#getSingleNodeValue() |
| */ |
| public Node getSingleNodeValue() throws XPathException { |
| |
| if ((m_resultType != ANY_UNORDERED_NODE_TYPE) && |
| (m_resultType != FIRST_ORDERED_NODE_TYPE)) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_CANT_CONVERT_TO_SINGLENODE, new Object[] {m_xpath.getPatternString(), getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR,fmsg); |
| // "The XPathResult of XPath expression {0} has an XPathResultType of {1} which cannot be converted to a single node. |
| // This method applies only to types ANY_UNORDERED_NODE_TYPE and FIRST_ORDERED_NODE_TYPE." |
| } |
| |
| NodeIterator result = null; |
| try { |
| result = m_resultObj.nodeset(); |
| } catch (TransformerException te) { |
| throw new XPathException(XPathException.TYPE_ERR,te.getMessage()); |
| } |
| |
| if (null == result) return null; |
| |
| Node node = result.nextNode(); |
| |
| // Wrap "namespace node" in an XPathNamespace |
| if (isNamespaceNode(node)) { |
| return new XPathNamespaceImpl(node); |
| } else { |
| return node; |
| } |
| } |
| |
| /** |
| * @see org.w3c.dom.xpath.XPathResult#getInvalidIteratorState() |
| */ |
| public boolean getInvalidIteratorState() { |
| return m_isInvalidIteratorState; |
| } |
| |
| /** |
| * The number of nodes in the result snapshot. Valid values for |
| * snapshotItem indices are <code>0</code> to |
| * <code>snapshotLength-1</code> inclusive. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or |
| * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>. |
| * |
| * @see org.w3c.dom.xpath.XPathResult#getSnapshotLength() |
| */ |
| public int getSnapshotLength() throws XPathException { |
| |
| if ((m_resultType != UNORDERED_NODE_SNAPSHOT_TYPE) && |
| (m_resultType != ORDERED_NODE_SNAPSHOT_TYPE)) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_CANT_GET_SNAPSHOT_LENGTH, new Object[] {m_xpath.getPatternString(), getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR,fmsg); |
| // "The method getSnapshotLength cannot be called on the XPathResult of XPath expression {0} because its XPathResultType is {1}. |
| } |
| |
| return m_list.getLength(); |
| } |
| |
| /** |
| * Iterates and returns the next node from the node set or |
| * <code>null</code>if there are no more nodes. |
| * @return Returns the next node. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>UNORDERED_NODE_ITERATOR_TYPE</code> or |
| * <code>ORDERED_NODE_ITERATOR_TYPE</code>. |
| * @exception DOMException |
| * INVALID_STATE_ERR: The document has been mutated since the result was |
| * returned. |
| * @see org.w3c.dom.xpath.XPathResult#iterateNext() |
| */ |
| public Node iterateNext() throws XPathException, DOMException { |
| if ((m_resultType != UNORDERED_NODE_ITERATOR_TYPE) && |
| (m_resultType != ORDERED_NODE_ITERATOR_TYPE)) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_NON_ITERATOR_TYPE, new Object[] {m_xpath.getPatternString(), getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR, fmsg); |
| // "The method iterateNext cannot be called on the XPathResult of XPath expression {0} because its XPathResultType is {1}. |
| // This method applies only to types UNORDERED_NODE_ITERATOR_TYPE and ORDERED_NODE_ITERATOR_TYPE."}, |
| } |
| |
| if (getInvalidIteratorState()) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_DOC_MUTATED, null); |
| throw new DOMException(DOMException.INVALID_STATE_ERR,fmsg); // Document mutated since result was returned. Iterator is invalid. |
| } |
| |
| Node node = m_iterator.nextNode(); |
| if(null == node) |
| removeEventListener(); // JIRA 1673 |
| // Wrap "namespace node" in an XPathNamespace |
| if (isNamespaceNode(node)) { |
| return new XPathNamespaceImpl(node); |
| } else { |
| return node; |
| } |
| } |
| |
| /** |
| * Returns the <code>index</code>th item in the snapshot collection. If |
| * <code>index</code> is greater than or equal to the number of nodes in |
| * the list, this method returns <code>null</code>. Unlike the iterator |
| * result, the snapshot does not become invalid, but may not correspond |
| * to the current document if it is mutated. |
| * @param index Index into the snapshot collection. |
| * @return The node at the <code>index</code>th position in the |
| * <code>NodeList</code>, or <code>null</code> if that is not a valid |
| * index. |
| * @exception XPathException |
| * TYPE_ERR: raised if <code>resultType</code> is not |
| * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or |
| * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>. |
| * |
| * @see org.w3c.dom.xpath.XPathResult#snapshotItem(int) |
| */ |
| public Node snapshotItem(int index) throws XPathException { |
| |
| if ((m_resultType != UNORDERED_NODE_SNAPSHOT_TYPE) && |
| (m_resultType != ORDERED_NODE_SNAPSHOT_TYPE)) { |
| String fmsg = XPATHMessages.createXPATHMessage(XPATHErrorResources.ER_NON_SNAPSHOT_TYPE, new Object[] {m_xpath.getPatternString(), getTypeString(m_resultType)}); |
| throw new XPathException(XPathException.TYPE_ERR, fmsg); |
| // "The method snapshotItem cannot be called on the XPathResult of XPath expression {0} because its XPathResultType is {1}. |
| // This method applies only to types UNORDERED_NODE_SNAPSHOT_TYPE and ORDERED_NODE_SNAPSHOT_TYPE."}, |
| } |
| |
| Node node = m_list.item(index); |
| |
| // Wrap "namespace node" in an XPathNamespace |
| if (isNamespaceNode(node)) { |
| return new XPathNamespaceImpl(node); |
| } else { |
| return node; |
| } |
| } |
| |
| |
| /** |
| * Check if the specified type is one of the supported types. |
| * @param type The specified type |
| * |
| * @return true If the specified type is supported; otherwise, returns false. |
| */ |
| static boolean isValidType( short type ) { |
| switch (type) { |
| case ANY_TYPE: |
| case NUMBER_TYPE: |
| case STRING_TYPE: |
| case BOOLEAN_TYPE: |
| case UNORDERED_NODE_ITERATOR_TYPE: |
| case ORDERED_NODE_ITERATOR_TYPE: |
| case UNORDERED_NODE_SNAPSHOT_TYPE: |
| case ORDERED_NODE_SNAPSHOT_TYPE: |
| case ANY_UNORDERED_NODE_TYPE: |
| case FIRST_ORDERED_NODE_TYPE: return true; |
| default: return false; |
| } |
| } |
| |
| /** |
| * @see org.w3c.dom.events.EventListener#handleEvent(Event) |
| */ |
| public void handleEvent(Event event) { |
| |
| if (event.getType().equals("DOMSubtreeModified")) { |
| // invalidate the iterator |
| m_isInvalidIteratorState = true; |
| |
| // deregister as a listener to reduce computational load |
| removeEventListener(); |
| } |
| } |
| |
| /** |
| * Given a request type, return the equivalent string. |
| * For diagnostic purposes. |
| * |
| * @return type string |
| */ |
| private String getTypeString(int type) |
| { |
| switch (type) { |
| case ANY_TYPE: return "ANY_TYPE"; |
| case ANY_UNORDERED_NODE_TYPE: return "ANY_UNORDERED_NODE_TYPE"; |
| case BOOLEAN_TYPE: return "BOOLEAN"; |
| case FIRST_ORDERED_NODE_TYPE: return "FIRST_ORDERED_NODE_TYPE"; |
| case NUMBER_TYPE: return "NUMBER_TYPE"; |
| case ORDERED_NODE_ITERATOR_TYPE: return "ORDERED_NODE_ITERATOR_TYPE"; |
| case ORDERED_NODE_SNAPSHOT_TYPE: return "ORDERED_NODE_SNAPSHOT_TYPE"; |
| case STRING_TYPE: return "STRING_TYPE"; |
| case UNORDERED_NODE_ITERATOR_TYPE: return "UNORDERED_NODE_ITERATOR_TYPE"; |
| case UNORDERED_NODE_SNAPSHOT_TYPE: return "UNORDERED_NODE_SNAPSHOT_TYPE"; |
| default: return "#UNKNOWN"; |
| } |
| } |
| |
| /** |
| * Given an XObject, determine the corresponding DOM XPath type |
| * |
| * @return type string |
| */ |
| private short getTypeFromXObject(XObject object) { |
| switch (object.getType()) { |
| case XObject.CLASS_BOOLEAN: return BOOLEAN_TYPE; |
| case XObject.CLASS_NODESET: return UNORDERED_NODE_ITERATOR_TYPE; |
| case XObject.CLASS_NUMBER: return NUMBER_TYPE; |
| case XObject.CLASS_STRING: return STRING_TYPE; |
| // XPath 2.0 types |
| // case XObject.CLASS_DATE: |
| // case XObject.CLASS_DATETIME: |
| // case XObject.CLASS_DTDURATION: |
| // case XObject.CLASS_GDAY: |
| // case XObject.CLASS_GMONTH: |
| // case XObject.CLASS_GMONTHDAY: |
| // case XObject.CLASS_GYEAR: |
| // case XObject.CLASS_GYEARMONTH: |
| // case XObject.CLASS_TIME: |
| // case XObject.CLASS_YMDURATION: return STRING_TYPE; // treat all date types as strings? |
| |
| case XObject.CLASS_RTREEFRAG: return UNORDERED_NODE_ITERATOR_TYPE; |
| case XObject.CLASS_NULL: return ANY_TYPE; // throw exception ? |
| default: return ANY_TYPE; // throw exception ? |
| } |
| |
| } |
| |
| /** |
| * Given a node, determine if it is a namespace node. |
| * |
| * @param node |
| * |
| * @return boolean Returns true if this is a namespace node; otherwise, returns false. |
| */ |
| private boolean isNamespaceNode(Node node) { |
| |
| if ((null != node) && |
| (node.getNodeType() == Node.ATTRIBUTE_NODE) && |
| (node.getNodeName().startsWith("xmlns:") || node.getNodeName().equals("xmlns"))) { |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * Add m_contextNode to Event Listner to listen for Mutations Events |
| * |
| */ |
| private void addEventListener(){ |
| if(m_contextNode instanceof EventTarget) |
| ((EventTarget)m_contextNode).addEventListener("DOMSubtreeModified",this,true); |
| |
| } |
| |
| |
| /** |
| * Remove m_contextNode to Event Listner to listen for Mutations Events |
| * |
| */ |
| private void removeEventListener(){ |
| if(m_contextNode instanceof EventTarget) |
| ((EventTarget)m_contextNode).removeEventListener("DOMSubtreeModified",this,true); |
| } |
| |
| } |
