net.sourceforge.tink.model.impl.TinkResource Maven / Gradle / Ivy

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/**
 * Copyright 2008,2009 Ivan SZKIBA
 * 
 * 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.
 * under the License.
 */

package net.sourceforge.tink.model.impl;

import net.sourceforge.tink.model.Page;
import net.sourceforge.tink.model.TinkContext;
import net.sourceforge.tink.model.TinkException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import java.net.URI;
import java.net.URISyntaxException;

import java.util.ArrayList;
import java.util.List;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathException;
import javax.xml.xpath.XPathFactory;

public class TinkResource extends AbstractTinkComponent
{
    private XPath xpath;

    public List findResources(Page page) throws TinkException
    {
        Document doc = page.getDocument();
        List refs = new ArrayList();

        try
        {
            findReferences(refs, doc, "//img", "src");
            findReferences(refs, doc, "//script", "src");
            findReferences(refs, doc, "//link", "href");
        }
        catch (XPathException x)
        {
            throw new TinkException(x);
        }

        // TODO complete this list, add all element with URI attributes....
        return refs;
    }

    @Override public void init(TinkContext ctx) throws TinkException
    {
        super.init(ctx);
        xpath = XPathFactory.newInstance().newXPath();
    }

    private void findReferences(List refs, Document doc, String expr, String attr) throws XPathException
    {

        // TODO investigate script without src problem !
        NodeList nodes = (NodeList) xpath.evaluate(expr, doc, XPathConstants.NODESET);

        for (int i = 0; i < nodes.getLength(); i++)
        {
            Element element = (Element) nodes.item(i);

            if (element.hasAttribute(attr))
            {
                try
                {
                    refs.add(new URI(element.getAttribute(attr)));
                }
                catch (URISyntaxException x)
                {
                    out.error(x, "Invalid attribute value. %s=%s", attr, element.getAttribute(attr));
                }
            }
        }
    }
}