org.ow2.mind.plugin.ConfigurationElementImpl.java Source code

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Here is the source code for org.ow2.mind.plugin.ConfigurationElementImpl.java

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/**
 * Copyright (C) 2010 STMicroelectronics
 *
 * This file is part of "Mind Compiler" is free software: you can redistribute 
 * it and/or modify it under the terms of the GNU Lesser General Public License 
 * as published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Contact: mind@ow2.org
 *
 * Authors: Matthieu Leclercq
 * Contributors: 
 */

package org.ow2.mind.plugin;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.objectweb.fractal.adl.CompilerError;
import org.objectweb.fractal.adl.error.GenericErrors;
import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;

class ConfigurationElementImpl implements ConfigurationElement {

    private final PluginImpl plugin;
    private final Object parent;
    private final String name;
    private final Map<String, String> attributes;
    private final List<ConfigurationElement> children;

    ConfigurationElementImpl(final PluginImpl plugin, final Object parent, final Element element) {
        this.plugin = plugin;
        this.parent = parent;
        name = element.getNodeName();
        final NamedNodeMap attrs = element.getAttributes();
        attributes = new HashMap<String, String>(attrs.getLength());
        for (int i = 0; i < attrs.getLength(); i++) {
            final Attr attr = (Attr) attrs.item(i);
            attributes.put(attr.getName(), attr.getValue());
        }

        final NodeList childNodes = element.getChildNodes();
        children = new ArrayList<ConfigurationElement>();
        for (int i = 0; i < childNodes.getLength(); i++) {
            final Node node = childNodes.item(i);
            if (!(node instanceof Element))
                continue;
            children.add(new ConfigurationElementImpl(plugin, this, (Element) node));
        }
    }

    public String getName() {
        return name;
    }

    public String getAttribute(final String name) {
        return attributes.get(name);
    }

    public String getAttribute(final String name, final String defaultValue) {
        return attributes.containsKey(name) ? attributes.get(name) : defaultValue;
    }

    public Map<String, String> getAttributes() {
        return Collections.unmodifiableMap(attributes);
    }

    public <T> T createInstance(final String attrName, final Class<T> expectedType) {
        final String className = getAttribute(attrName);
        if (className == null)
            return null;
        Class<?> uncastedClass;
        try {
            uncastedClass = plugin.getClassLoader().loadClass(className);
        } catch (final ClassNotFoundException e) {
            throw new CompilerError(GenericErrors.GENERIC_ERROR, e, "Can't load class '" + className + "'");
        }
        Class<? extends T> castedClass;
        try {
            castedClass = uncastedClass.asSubclass(expectedType);
        } catch (final ClassCastException e) {
            throw new CompilerError(GenericErrors.GENERIC_ERROR, e,
                    "Class '" + className + "' is not a sub-class of '" + expectedType.getName() + "'.");
        }
        return plugin.getPluginManager().getInstance(castedClass);
    }

    public Iterable<ConfigurationElement> getChildren() {
        return Iterables.unmodifiableIterable(children);
    }

    public ConfigurationElement getChild() {
        if (children.isEmpty())
            return null;
        else
            return children.get(0);
    }

    public Iterable<ConfigurationElement> getChildren(final String name) {
        return Iterables.filter(children, new Predicate<ConfigurationElement>() {

            public boolean apply(final ConfigurationElement input) {
                return input.getName().equals(name);
            }
        });
    }

    public ConfigurationElement getChild(final String name) {
        final Iterator<ConfigurationElement> children = getChildren(name).iterator();
        return children.hasNext() ? children.next() : null;
    }

    public Object getParent() {
        return parent;
    }

    void setAttribute(final String name, final String value) {
        attributes.put(name, value);
    }

}