xml.java

這是一個javascript 的 interpreter是了解 web browser的好材料

/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Rhino code, released
 * May 6, 1999.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1997-2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Ethan Hugg
 *   Terry Lucas
 *   Milen Nankov
 *   David P. Caldwell <[e-mail]>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License Version 2 or later (the "GPL"), in which
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 * not delete the provisions above, a recipient may use your version of this
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package org.mozilla.javascript.xmlimpl;

import org.mozilla.javascript.*;
import org.mozilla.javascript.xml.XMLObject;

class XML extends XMLObjectImpl {
    static final long serialVersionUID = -630969919086449092L;

    private XmlNode node;

    XML(XMLLibImpl lib, Scriptable scope, XMLObject prototype, XmlNode node) {
      super(lib, scope, prototype);
      initialize(node);
    }

    void initialize(XmlNode node) {
        this.node = node;
        this.node.setXml(this);
    }

    final XML getXML() {
        return this;
    }

    void replaceWith(XML value) {
        //    We use the underlying document structure if the node is not
        //    "standalone," but we need to just replace the XmlNode instance
        //    otherwise
        if (this.node.parent() != null || false) {
            this.node.replaceWith(value.node);
        } else {
            this.initialize(value.node);
        }
    }

    /** @deprecated I would love to encapsulate this somehow. */
    XML makeXmlFromString(XMLName name, String value) {
        try {
            return newTextElementXML(this.node, name.toQname(), value.toString());
        } catch(Exception e) {
            throw ScriptRuntime.typeError(e.getMessage());
        }
    }

    /** @deprecated Rename this, at the very least.  But it's not clear it's even necessary */
    XmlNode getAnnotation() {
        return node;
    }

    //
    //  Methods from ScriptableObject
    //

    //    TODO Either cross-reference this next comment with the specification or delete it and change the behavior
    //    The comment: XML[0] should return this, all other indexes are Undefined
    public Object get(int index, Scriptable start) {
        if (index == 0) {
            return this;
        } else {
            return Scriptable.NOT_FOUND;
        }
    }

    public boolean has(int index, Scriptable start) {
        return (index == 0);
    }

    public void put(int index, Scriptable start, Object value) {
        //    TODO    Clarify the following comment and add a reference to the spec
        //    The comment: Spec says assignment to indexed XML object should return type error
        throw ScriptRuntime.typeError("Assignment to indexed XML is not allowed");
    }

    public Object[] getIds() {
        if (isPrototype()) {
            return new Object[0];
        } else {
            return new Object[] { new Integer(0) };
        }
    }

    //    TODO    This is how I found it but I am not sure it makes sense
    public void delete(int index) {
        if (index == 0) {
            this.remove();
        }
    }

    //
    //    Methods from XMLObjectImpl
    //

    boolean hasXMLProperty(XMLName xmlName) {
        if (isPrototype()) {
            return getMethod(xmlName.localName()) != NOT_FOUND;
        } else {
            return (getPropertyList(xmlName).length() > 0) || (getMethod(xmlName.localName()) != NOT_FOUND);
        }
    }

    Object getXMLProperty(XMLName xmlName) {
        if (isPrototype()) {
            return getMethod(xmlName.localName());
        } else {
            return getPropertyList(xmlName);
        }
    }

    //
    //
    //    Methods that merit further review
    //
    //

    XmlNode.QName getNodeQname() {
        return this.node.getQname();
    }

    XML[] getChildren() {
        if (!isElement()) return null;
        XmlNode[] children = this.node.getMatchingChildren(XmlNode.Filter.TRUE);
        XML[] rv = new XML[children.length];
        for (int i=0; i<rv.length; i++) {
            rv[i] = toXML(children[i]);
        }
        return rv;
    }

    XML[] getAttributes() {
        XmlNode[] attributes = this.node.getAttributes();
        XML[] rv = new XML[attributes.length];
        for (int i=0; i<rv.length; i++) {
            rv[i] = toXML(attributes[i]);
        }
        return rv;
    }

    //    Used only by XML, XMLList
    XMLList getPropertyList(XMLName name) {
        return name.getMyValueOn(this);
    }

    void deleteXMLProperty(XMLName name) {
        XMLList list = getPropertyList(name);
        for (int i=0; i<list.length(); i++) {
            list.item(i).node.deleteMe();
        }
    }

    void putXMLProperty(XMLName xmlName, Object value) {
        if (isPrototype()) {
            //    TODO    Is this really a no-op?  Check the spec to be sure
        } else {
            xmlName.setMyValueOn(this, value);
        }
    }

    boolean hasOwnProperty(XMLName xmlName) {
        boolean hasProperty = false;

        if (isPrototype()) {
            String property = xmlName.localName();
            hasProperty = (0 != findPrototypeId(property));
        } else {
            hasProperty = (getPropertyList(xmlName).length() > 0);
        }

        return hasProperty;
    }

    protected Object jsConstructor(Context cx, boolean inNewExpr, Object[] args) {
        if (args.length == 0 || args[0] == null || args[0] == Undefined.instance) {
            args = new Object[] { "" };
        }
        //    ECMA 13.4.2 does not appear to specify what to do if multiple arguments are sent.
        XML toXml = ecmaToXml(args[0]);
        if (inNewExpr) {
            return toXml.copy();
        } else {
            return toXml;
        }
    }

    //    See ECMA 357, 11_2_2_1, Semantics, 3_f.
    public Scriptable getExtraMethodSource(Context cx) {
        if (hasSimpleContent()) {
            String src = toString();
            return ScriptRuntime.toObjectOrNull(cx, src);
        }
        return null;
    }

    //
    //    TODO    Miscellaneous methods not yet grouped
    //

    void removeChild(int index) {
        this.node.removeChild(index);
    }

    void normalize() {
        this.node.normalize();
    }

    private XML toXML(XmlNode node) {
        if (node.getXml() == null) {
            node.setXml(newXML(node));
        }
        return node.getXml();
    }

    void setAttribute(XMLName xmlName, Object value) {
        if (!isElement()) throw new IllegalStateException("Can only set attributes on elements.");
        //    TODO    Is this legal, but just not "supported"?  If so, support it.
        if (xmlName.uri() == null && xmlName.localName().equals("*")) {
            throw ScriptRuntime.typeError("@* assignment not supported.");
        }
        this.node.setAttribute(xmlName.toQname(), ScriptRuntime.toString(value));
    }

    void remove() {
        this.node.deleteMe();
    }

    void addMatches(XMLList rv, XMLName name) {
        name.addMatches(rv, this);
    }

    XMLList elements(XMLName name) {
        XMLList rv = newXMLList();
        rv.setTargets(this, name.toQname());
        //    TODO    Should have an XMLNode.Filter implementation based on XMLName
        XmlNode[] elements = this.node.getMatchingChildren(XmlNode.Filter.ELEMENT);
        for (int i=0; i<elements.length; i++) {
            if (name.matches( toXML(elements[i]) )) {
                rv.addToList( toXML(elements[i]) );
            }
        }
        return rv;
    }

    XMLList child(XMLName xmlName) {
        //    TODO    Right now I think this method would allow child( "@xxx" ) to return the xxx attribute, which is wrong

        XMLList rv = newXMLList();

        //    TODO    Should this also match processing instructions?  If so, we have to change the filter and also the XMLName
        //            class to add an acceptsProcessingInstruction() method

        XmlNode[] elements = this.node.getMatchingChildren(XmlNode.Filter.ELEMENT);
        for (int i=0; i<elements.length; i++) {
            if (xmlName.matchesElement(elements[i].getQname())) {
                rv.addToList( toXML(elements[i]) );
            }
        }
        rv.setTargets(this, xmlName.toQname());
        return rv;
    }

    XML replace(XMLName xmlName, Object xml) {
        putXMLProperty(xmlName, xml);
        return this;
    }

    XMLList children() {
        XMLList rv = newXMLList();
        XMLName all = XMLName.formStar();
        rv.setTargets(this, all.toQname());
        XmlNode[] children = this.node.getMatchingChildren(XmlNode.Filter.TRUE);
        for (int i=0; i<children.length; i++) {
            rv.addToList( toXML(children[i]) );
        }
        return rv;
    }

    XMLList child(int index) {
        //    ECMA357 13.4.4.6 (numeric case)
        XMLList result = newXMLList();
        result.setTargets(this, null);
        if (index >= 0 && index < this.node.getChildCount()) {
            result.addToList(getXmlChild(index));
        }
        return result;
    }

    XML getXmlChild(int index) {
        XmlNode child = this.node.getChild(index);
        if (child.getXml() == null) {
            child.setXml(newXML(child));
        }
        return child.getXml();
    }

    int childIndex() {
        return this.node.getChildIndex();
    }

    boolean contains(Object xml) {
        if (xml instanceof XML) {
            return equivalentXml(xml);
        } else {
            return false;
        }
    }

    //    Method overriding XMLObjectImpl
    boolean equivalentXml(Object target) {
        boolean result = false;

        if (target instanceof XML) {
            //    TODO    This is a horrifyingly inefficient way to do this so we should make it better.  It may also not work.
            return this.node.toXmlString(getProcessor()).equals( ((XML)target).node.toXmlString(getProcessor()) );
        } else if (target instanceof XMLList) {
            //    TODO    Is this right?  Check the spec ...
            XMLList otherList = (XMLList) target;

            if (otherList.length() == 1) {
                result = equivalentXml(otherList.getXML());
            }
        } else if (hasSimpleContent()) {
            String otherStr = ScriptRuntime.toString(target);

            result = toString().equals(otherStr);
        }

        return result;
    }