ListPropertyConverter.java

/*
 * Copyright 2010-2025 James Pether Sörling
 *
 * 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.
 *
 *  $Id$
 *  $HeadURL$
*/
package com.hack23.cia.web.impl.ui.application.views.common.converters;

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.PropertyUtilsBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.vaadin.data.Converter;
import com.vaadin.data.Result;
import com.vaadin.data.ValueContext;
import com.vaadin.data.ValueProvider;

/**
 * The Class ListPropertyRenderer.
 */
public final class ListPropertyConverter implements Converter<String, List<?>>,ValueProvider<Object, String> {

    /** The Constant CONTENT_SEPARATOR. */
    private static final char CONTENT_SEPARATOR = ' ';

    /** The Constant END_TAG. */
    private static final char END_TAG = ']';

    /** The Constant LOGGER. */
    private static final Logger LOGGER = LoggerFactory.getLogger(ListPropertyConverter.class);

    /** The Constant PROPERTY_UTILS_BEAN. */
    private static final PropertyUtilsBean PROPERTY_UTILS_BEAN= new PropertyUtilsBean();

    /** The Constant serialVersionUID. */
    private static final long serialVersionUID = 1L;

    /** The Constant START_TAG. */
    private static final char START_TAG = '[';

    /** The column. */
    private final String column;

    /** The fallback column. */
    private final String fallbackColumn;

    /** The property. */
    private final String property;

    /**
     * Instantiates a new collection property converter.
     * @param property
     *            the property
     * @param column
     *            the column
     */
    public ListPropertyConverter(final String property, final String column) {
        super();
        this.property = property;
        this.column = column;
        this.fallbackColumn = null;
    }

    /**
     * Instantiates a new list property converter.
     * @param property
     *            the property
     * @param column
     *            the column
     * @param fallbackColumn
     *            the fallback column
     */
    public ListPropertyConverter(final String property, final String column, final String fallbackColumn) {
        super();
        this.property = property;
        this.column = column;
        this.fallbackColumn = fallbackColumn;
    }


    /**
     * Adds the fallback value.
     *
     * @param stringBuilder the string builder
     * @param object        the object
     * @throws IllegalAccessException    the illegal access exception
     * @throws InvocationTargetException the invocation target exception
     * @throws NoSuchMethodException     the no such method exception
     */
    private void addFallbackValue(final StringBuilder stringBuilder, final Object object)
            throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        if (fallbackColumn != null) {
            final String beanPropertyFallBack = BeanUtils.getProperty(object, fallbackColumn);
            if (beanPropertyFallBack != null) {
                stringBuilder.append(beanPropertyFallBack);
            }
        }
    }

    /**
     * Append object presentation.
     *
     * @param stringBuilder
     *            the string builder
     * @param object
     *            the object
     */
    private void appendObjectPresentation(final StringBuilder stringBuilder, final Object object) {
        try {
            final String beanProperty = BeanUtils.getProperty(object, property);

            if (beanProperty != null) {
                stringBuilder.append(beanProperty);
            } else {
                addFallbackValue(stringBuilder, object);
            }

        } catch (final IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
            LOGGER.warn("Problem getting property {}, object {} , exception {}", property, object, e);
        }
        stringBuilder.append(CONTENT_SEPARATOR);
    }

    @Override
    public String apply(final Object source) {
        List<?> list;
        try {
            list = (List<?>) PROPERTY_UTILS_BEAN.getProperty(source, column);
            return convertToPresentation(list,null);
        } catch (final IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
            LOGGER.warn("Problem getting list {}, object {} , exception {}", property, column, e);
        }
        return "";
    }

    @Override
    public Result<List<?>> convertToModel(final String value, final ValueContext context) {
        return Result.ok(new ArrayList<>());
    }

    @Override
    public String convertToPresentation(final List<?> value, final ValueContext context) {
        final StringBuilder stringBuilder = new StringBuilder();

        if (value != null) {
            stringBuilder.append(START_TAG);
            for (final Object object : value) {
                appendObjectPresentation(stringBuilder, object);
            }
            stringBuilder.append(END_TAG);
        }


        return stringBuilder.toString();
    }

    /**
     * Gets the column.
     *
     * @return the column
     */
    public String getColumn() {
        return column;
    }

}