de.xwic.appkit.webbase.editors.mappers.MapperFactory.java Source code

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Here is the source code for de.xwic.appkit.webbase.editors.mappers.MapperFactory.java

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/*
 * Copyright 2015 xWic group (http://www.xwic.de)
 *
 * 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 de.xwic.appkit.webbase.editors.mappers;

import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import de.jwic.base.IControl;
import de.xwic.appkit.core.config.editor.UIElement;
import de.xwic.appkit.core.config.model.EntityDescriptor;
import de.xwic.appkit.core.registry.ExtensionRegistry;
import de.xwic.appkit.core.registry.IExtension;
import de.xwic.appkit.webbase.editors.EditorConfigurationException;
import de.xwic.appkit.webbase.editors.builders.Builder;
import de.xwic.appkit.webbase.editors.builders.BuilderRegistry;

import javax.swing.text.html.HTML;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Creates a mapper instance of the specified type. This factory knows only the
 * standard mappers. Custom mappers need to be created during the build phase.
 * 
 * @author Lippisch
 */
public class MapperFactory {

    public final static String EXP_ENTITY_EDITOR_MAPPER = "entityEditorMapper";

    private final static Log log = LogFactory.getLog(MapperFactory.class);

    private static MapperFactory instance = null;

    private Map<String, Class<? extends PropertyMapper<?>>> knownMappers = new HashMap<String, Class<? extends PropertyMapper<?>>>();

    /**
     * Private constructor, turning this class into a singleton.
     */
    @SuppressWarnings("unchecked")
    private MapperFactory() {

        knownMappers.put(InputboxMapper.MAPPER_ID, InputboxMapper.class);
        knownMappers.put(HtmlEditorMapper.MAPPER_ID, HtmlEditorMapper.class);
        knownMappers.put(NumericInputboxMapper.MAPPER_ID, NumericInputboxMapper.class);
        knownMappers.put(PicklistEntryMapper.MAPPER_ID, PicklistEntryMapper.class);
        knownMappers.put(PicklistEntrySetMapper.MAPPER_ID, PicklistEntrySetMapper.class);
        knownMappers.put(YesNoRadioGroupMapper.MAPPER_ID, YesNoRadioGroupMapper.class);
        knownMappers.put(EntitySelectorMapper.MAPPER_ID, EntitySelectorMapper.class);
        knownMappers.put(DatePickerMapper.MAPPER_ID, DatePickerMapper.class);
        knownMappers.put(ListViewMapper.MAPPER_ID, ListViewMapper.class);

        // register 'extensions'
        List<IExtension> extensions = ExtensionRegistry.getInstance().getExtensions(EXP_ENTITY_EDITOR_MAPPER);
        for (IExtension ex : extensions) {
            try {
                String mapperClazz = ex.getClassName();
                Class<PropertyMapper<?>> clazz = (Class<PropertyMapper<?>>) Class.forName(mapperClazz);
                if (knownMappers.containsKey(ex.getId())) {
                    log.info(
                            "Mapper with ID '" + ex.getId() + "' is already registered. Mapper will be overriden.");
                }
                knownMappers.put(ex.getId(), clazz);
                log.info("Registered mapper with id " + ex.getId());
            } catch (Exception e) {
                log.error("Error registering custom builder id '" + ex.getId() + "'", e);
            }
        }

    }

    /**
     * Returns the single instance of the StandardMapperFactory.
     * @return
     */
    public static MapperFactory instance() {
        if (instance == null) {
            synchronized (MapperFactory.class) {
                if (instance == null) {
                    instance = new MapperFactory();
                }
            }
        }
        return instance;
    }

    /**
     * Create a mapper instance fo the given type.
     * @param mapperId
     * @return
     * @throws EditorConfigurationException 
     */
    @SuppressWarnings("rawtypes")
    public PropertyMapper<IControl> createMapper(String mapperId, EntityDescriptor descriptor)
            throws EditorConfigurationException {

        Class<? extends PropertyMapper<?>> clazz = knownMappers.get(mapperId);
        if (clazz == null) {
            throw new IllegalArgumentException("A mapper with the id '" + mapperId + "' is unknown.");
        }

        try {
            Constructor<? extends PropertyMapper> constructor = clazz.getConstructor(EntityDescriptor.class);
            @SuppressWarnings("unchecked")
            PropertyMapper<IControl> mapper = constructor.newInstance(descriptor);
            return mapper;

        } catch (Exception e) {
            throw new EditorConfigurationException(
                    "Cannot create mapper id '" + mapperId + "' (" + clazz.getName() + ")", e);
        }

    }

}