org.xmlbeam.AutoValue Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of xmlprojector Show documentation
The coolest XML library for Java around. Define typesafe views (projections) to xml. Use XPath to read and write XML. Bind XML to Java collections. Requires at least Java6, supports Java8 features and has no further runtime dependencies.
There is a newer version: 1.4.24
Show newest version
/**
 *  Copyright 2016 Sven Ewald
 *
 *  Licensed 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.
 */
package org.xmlbeam;

import java.util.Iterator;

import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;

import org.w3c.dom.Attr;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xmlbeam.dom.DOMAccess;
import org.xmlbeam.evaluation.DefaultXPathEvaluator;
import org.xmlbeam.evaluation.InvocationContext;
import org.xmlbeam.types.XBAutoValue;
import org.xmlbeam.util.intern.DOMHelper;

/**
 *
 */
class AutoValue implements XBAutoValue {

    private final InvocationContext invocationContext;
    private Node dataNode;
    private Node baseNode = null;
//    private Element parent;

    private final DomChangeTracker domChangeTracker = new DomChangeTracker() {
        @Override
        void refresh(final boolean forWrite) throws XPathExpressionException {
            final NodeList nodes = (NodeList) invocationContext.getxPathExpression().evaluate(baseNode, XPathConstants.NODESET);;
            if ((nodes.getLength() == 0) && forWrite) {
                //  parent = invocationContext.getDuplexExpression().ensureParentExistence(baseNode);
                dataNode = invocationContext.getDuplexExpression().ensureExistence(baseNode);
                return;
            } else {
                // parent = nodes.getLength() == 0 ? null : (Element) nodes.item(0).getParentNode();
            }
            dataNode = nodes.getLength() == 0 ? null : nodes.item(0);
        }
    };

    /**
     * @param baseNode
     * @param invocationContext
     */
    public AutoValue(final Node baseNode, final InvocationContext invocationContext) {
        this.baseNode = baseNode;
        this.invocationContext = invocationContext;
        invocationContext.getProjector().addDOMChangeListener(domChangeTracker);

    }

    @Override
    public E get() {
        domChangeTracker.refreshForReadIfNeeded();
        if (dataNode == null) {
            return null;
        }
        return DefaultXPathEvaluator.convertToComponentType(invocationContext, dataNode, invocationContext.getTargetComponentType());
    }

    @Override
    public E set(final E element) {
        if (dataNode == null) {
            domChangeTracker.domChanged();
        }
        domChangeTracker.refreshForReadIfNeeded();
        Node prevNode = dataNode;
//        domChangeTracker.refreshForWriteIfNeeded();
        E result = DefaultXPathEvaluator.convertToComponentType(invocationContext, prevNode, invocationContext.getTargetComponentType());
        Node oldNode = dataNode;
        domChangeTracker.domChanged();
        domChangeTracker.refreshForWriteIfNeeded();
        if (element instanceof Node) {
            Node newNode = ((Node) element).cloneNode(true);
            oldNode.getParentNode().replaceChild(oldNode, newNode);
            dataNode = newNode;
            return result;
        }
        if (element instanceof DOMAccess) {
            Node newNode = ((DOMAccess) element).getDOMBaseElement().cloneNode(true);
            oldNode.getParentNode().replaceChild(oldNode, newNode);
            dataNode = newNode;
            return result;
        }

        final String asString = invocationContext.getProjector().config().getStringRenderer().render(element.getClass(), element, invocationContext.getDuplexExpression().getExpressionFormatPattern());
        dataNode.setTextContent(asString);
        return result;
    }

    @Override
    public E remove() {
        // refresh done in get()
        //domChangeTracker.refreshForReadIfNeeded();
        E oldValue = get();
        if (dataNode == null) {
            return oldValue;
        }
        if (dataNode.getNodeType() == Node.ATTRIBUTE_NODE) {
            DOMHelper.removeAttribute((Attr) dataNode);
            dataNode = null;
            return oldValue;
        }

        if (dataNode.getParentNode() == null) {
            return oldValue;
        }
        DOMHelper.trim(dataNode);
        dataNode.getParentNode().removeChild(dataNode);
        dataNode = null;
        return oldValue;
    }

    @Override
    public boolean isPresent() {
        domChangeTracker.refreshForReadIfNeeded();
        return dataNode != null;
    }

    @Override
    public Iterator iterator() {
        return new Iterator() {
            boolean read = !(isPresent());

            @Override
            public boolean hasNext() {
                return (!read) && (isPresent());
            }

            @Override
            public E next() {
                if (read) {
                    throw new IllegalStateException();
                }
                read = true;
                return get();
            }

            @Override
            public void remove() {
                if ((!read) || (!isPresent())) {
                    throw new IllegalStateException();
                }
                AutoValue.this.remove();
            }
        };
    }

    @Override
    public XBAutoValue rename(final String newName) {
        domChangeTracker.domChanged();
        domChangeTracker.refreshForWriteIfNeeded();
        if (dataNode == null) {
            throw new IllegalStateException("Can not rename when no value is present.");
        }
        dataNode = DOMHelper.renameNode(dataNode, newName);
        domChangeTracker.domChanged();
        return this;
    }

    @Override
    public String getName() {
        domChangeTracker.refreshForReadIfNeeded();
        if (dataNode == null) {
            throw new IllegalStateException("No value is present.");
        }
        return dataNode.getNodeName();
    }

    Node getNode() {
        domChangeTracker.refreshForReadIfNeeded();
        return dataNode;
    }

    @Override
    public boolean equals(final Object o) {
        if (!isPresent()) {
            return false;
        }
        E e = get();
        if (e == null) {
            return false;
        }
        return e.equals(o);
    }

    @Override
    public int hashCode() {
        if (!isPresent()) {
            return 0;
        }
        E e = get();
        if (e == null) {
            return 0;
        }
        return get().hashCode();
    }

}