xml.java

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

    XMLObjectImpl copy() {
        return newXML( this.node.copy() );
    }

    boolean hasSimpleContent() {
        if (isComment() || isProcessingInstruction()) return false;
        if (isText() || this.node.isAttributeType()) return true;
        return !this.node.hasChildElement();
    }

    boolean hasComplexContent() {
        return !hasSimpleContent();
    }

    //    TODO Cross-reference comment below with spec
    //    Comment is: Length of an XML object is always 1, it's a list of XML objects of size 1.
    int length() {
        return 1;
    }

    //    TODO    it is not clear what this method was for ...
    boolean is(XML other) {
        return this.node.isSameNode(other.node);
    }

    Object nodeKind() {
        return ecmaClass();
    }

    Object parent() {
        XmlNode parent = this.node.parent();
        if (parent == null) return null;
        return newXML(this.node.parent());
    }

    boolean propertyIsEnumerable(Object name)
    {
        boolean result;
        if (name instanceof Integer) {
            result = (((Integer)name).intValue() == 0);
        } else if (name instanceof Number) {
            double x = ((Number)name).doubleValue();
            // Check that number is positive 0
            result = (x == 0.0 && 1.0 / x > 0);
        } else {
            result = ScriptRuntime.toString(name).equals("0");
        }
        return result;
    }

    Object valueOf() {
        return this;
    }

    //
    //    Selection of children
    //

    XMLList comments() {
        XMLList rv = newXMLList();
        this.node.addMatchingChildren(rv, XmlNode.Filter.COMMENT);
        return rv;
    }

    XMLList text() {
        XMLList rv = newXMLList();
        this.node.addMatchingChildren(rv, XmlNode.Filter.TEXT);
        return rv;
    }

    XMLList processingInstructions(XMLName xmlName) {
        XMLList rv = newXMLList();
        this.node.addMatchingChildren(rv, XmlNode.Filter.PROCESSING_INSTRUCTION(xmlName));
        return rv;
    }

    //
    //    Methods relating to modification of child nodes
    //

    //    We create all the nodes we are inserting before doing the insert to
    //    avoid nasty cycles caused by mutability of these objects.  For example,
    //    what if the toString() method of value modifies the XML object we were
    //    going to insert into?  insertAfter might get confused about where to
    //    insert.  This actually came up with SpiderMonkey, leading to a (very)
    //    long discussion.  See bug #354145.
    private XmlNode[] getNodesForInsert(Object value) {
        if (value instanceof XML) {
            return new XmlNode[] { ((XML)value).node };
        } else if (value instanceof XMLList) {
            XMLList list = (XMLList)value;
            XmlNode[] rv = new XmlNode[list.length()];
            for (int i=0; i<list.length(); i++) {
                rv[i] = list.item(i).node;
            }
            return rv;
        } else {
            return new XmlNode[] {
                XmlNode.createText(getProcessor(), ScriptRuntime.toString(value))
            };
        }
    }

    XML replace(int index, Object xml) {
        XMLList xlChildToReplace = child(index);
        if (xlChildToReplace.length() > 0) {
            // One exists an that index
            XML childToReplace = xlChildToReplace.item(0);
            insertChildAfter(childToReplace, xml);
            removeChild(index);
        }
        return this;
    }

    XML prependChild(Object xml) {
        if (this.node.isParentType()) {
            this.node.insertChildrenAt(0, getNodesForInsert(xml));
        }
        return this;
    }

    XML appendChild(Object xml) {
        if (this.node.isParentType()) {
            XmlNode[] nodes = getNodesForInsert(xml);
            this.node.insertChildrenAt(this.node.getChildCount(), nodes);
        }
        return this;
    }

    private int getChildIndexOf(XML child) {
        for (int i=0; i<this.node.getChildCount(); i++) {
            if (this.node.getChild(i).isSameNode(child.node)) {
                return i;
            }
        }
        return -1;
    }

    XML insertChildBefore(XML child, Object xml) {
        if (child == null) {
            // Spec says inserting before nothing is the same as appending
            appendChild(xml);
        } else {
            XmlNode[] toInsert = getNodesForInsert(xml);
            int index = getChildIndexOf(child);
            if (index != -1) {
                this.node.insertChildrenAt(index, toInsert);
            }
        }

        return this;
    }

    XML insertChildAfter(XML child, Object xml) {
        if (child == null) {
            // Spec says inserting after nothing is the same as prepending
            prependChild(xml);
        } else {
            XmlNode[] toInsert = getNodesForInsert(xml);
            int index = getChildIndexOf(child);
            if (index != -1) {
                this.node.insertChildrenAt(index+1, toInsert);
            }
        }

        return this;
    }

    XML setChildren(Object xml) {
        //    TODO    Have not carefully considered the spec but it seems to call for this
        if (!isElement()) return this;

        while(this.node.getChildCount() > 0) {
            this.node.removeChild(0);
        }
        XmlNode[] toInsert = getNodesForInsert(xml);
        // append new children
        this.node.insertChildrenAt(0, toInsert);

        return this;
    }

    //
    //    Name and namespace-related methods
    //

    private void addInScopeNamespace(Namespace ns) {
        if (!isElement()) {
            return;
        }
        //    See ECMA357 9.1.1.13
        //    in this implementation null prefix means ECMA undefined
        if (ns.prefix() != null) {
            if (ns.prefix().length() == 0 && ns.uri().length() == 0) {
                return;
            }
            if (node.getQname().getNamespace().getPrefix().equals(ns.prefix())) {
                node.invalidateNamespacePrefix();
            }
            node.declareNamespace(ns.prefix(), ns.uri());
        } else {
            return;
        }
    }

    Namespace[] inScopeNamespaces() {
        XmlNode.Namespace[] inScope = this.node.getInScopeNamespaces();
        return createNamespaces(inScope);
    }

    private XmlNode.Namespace adapt(Namespace ns) {
        if (ns.prefix() == null) {
            return XmlNode.Namespace.create(ns.uri());
        } else {
            return XmlNode.Namespace.create(ns.prefix(), ns.uri());
        }
    }

    XML removeNamespace(Namespace ns) {
        if (!isElement()) return this;
        this.node.removeNamespace(adapt(ns));
        return this;
    }

    XML addNamespace(Namespace ns) {
        addInScopeNamespace(ns);
        return this;
    }

    QName name() {
        if (isText() || isComment()) return null;
        if (isProcessingInstruction()) return newQName("", this.node.getQname().getLocalName(), null);
        return newQName(node.getQname());
    }

    Namespace[] namespaceDeclarations() {
        XmlNode.Namespace[] declarations = node.getNamespaceDeclarations();
        return createNamespaces(declarations);
    }

    Namespace namespace(String prefix) {
        if (prefix == null) {
            return createNamespace( this.node.getNamespaceDeclaration() );
        } else {
            return createNamespace( this.node.getNamespaceDeclaration(prefix) );
        }
    }

    String localName() {
        if (name() == null) return null;
        return name().localName();
    }

    void setLocalName(String localName) {
        //    ECMA357 13.4.4.34
        if (isText() || isComment()) return;
        this.node.setLocalName(localName);
    }

    void setName(QName name) {
        //    See ECMA357 13.4.4.35
        if (isText() || isComment()) return;
        if (isProcessingInstruction()) {
            //    Spec says set the name URI to empty string and then set the [[Name]] property, but I understand this to do the same
            //    thing, unless we allow colons in processing instruction targets, which I think we do not.
            this.node.setLocalName(name.localName());
            return;
        }
        node.renameNode(name.getDelegate());
    }

    void setNamespace(Namespace ns) {
        //    See ECMA357 13.4.4.36
        if (isText() || isComment() || isProcessingInstruction()) return;
        setName(newQName(ns.uri(), localName(), ns.prefix()));
    }

    final String ecmaClass() {
        //    See ECMA357 9.1

        //    TODO    See ECMA357 9.1.1 last paragraph for what defaults should be

        if (node.isTextType()) {
            return "text";
        } else if (node.isAttributeType()) {
            return "attribute";
        } else if (node.isCommentType()) {
            return "comment";
        } else if (node.isProcessingInstructionType()) {
            return "processing-instruction";
        } else if (node.isElementType()) {
            return "element";
        } else {
            throw new RuntimeException("Unrecognized type: " + node);
        }
    }

    public String getClassName() {
        //    TODO:    This appears to confuse the interpreter if we use the "real" class property from ECMA.  Otherwise this code
        //    would be:
        //    return ecmaClass();
        return "XML";
    }

    private String ecmaValue() {
        return node.ecmaValue();
    }

    private String ecmaToString() {
        //    See ECMA357 10.1.1
        if (isAttribute() || isText()) {
            return ecmaValue();
        }
        if (this.hasSimpleContent()) {
            StringBuffer rv = new StringBuffer();
            for (int i=0; i < this.node.getChildCount(); i++) {
                XmlNode child = this.node.getChild(i);
                if (!child.isProcessingInstructionType() &&
                    !child.isCommentType())
                {
                    // TODO: Probably inefficient; taking clean non-optimized
                    // solution for now
                    XML x = new XML(getLib(), getParentScope(),
                                    (XMLObject)getPrototype(), child);
                    rv.append(x.toString());
                }
            }
            return rv.toString();
        }
        return toXMLString();
    }

    public String toString() {
        return ecmaToString();
    }

    String toXMLString() {
        return this.node.ecmaToXMLString(getProcessor());
    }

    final boolean isAttribute() {
        return node.isAttributeType();
    }

    final boolean isComment() {
        return node.isCommentType();
    }

    final boolean isText() {
        return node.isTextType();
    }

    final boolean isElement() {
        return node.isElementType();
    }

    final boolean isProcessingInstruction() {
        return node.isProcessingInstructionType();
    }

    //    Support experimental Java interface
    org.w3c.dom.Node toDomNode() {
        return node.toDomNode();
    }
}