SortInfoListValidator.java

/*
 * (C) Copyright 2010 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * 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.
 *
 * Contributors:
 *     Anahide Tchertchian
 */
package org.nuxeo.ecm.platform.ui.web.validator;

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

import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.validator.Validator;
import javax.faces.validator.ValidatorException;

import org.apache.commons.lang.StringUtils;
import org.nuxeo.ecm.core.api.SortInfo;

import com.sun.faces.util.MessageFactory;

/**
 * Validator for a list of {@link SortInfo} elements, checking that there is no conflicting sort information (several
 * sorts on same criterion)
 *
 * @author Anahide Tchertchian
 */
public class SortInfoListValidator implements Validator {

    public static final String VALIDATOR_ID = "SortInfoListValidator";

    /**
     * The message identifier of the {@link javax.faces.application.FacesMessage} to be created if the value to validate
     * is not a list of sort infos.
     */
    public static final String INVALID_VALUE_MESSAGE_ID = "error.sortInfoValidator.invalidValue";

    /**
     * The message identifier of the {@link javax.faces.application.FacesMessage} to be created if the value to validate
     * is a list of sort infos with conflicting criteria (several sorts on the same criterion).
     * <p>
     * The message format string for this message may optionally include the following placeholders:
     * <ul>
     * <li><code>{0}</code> replaced by the first found duplicate criterion.</li>
     * </ul>
     */
    public static final String CONFLICTING_CRITERIA_MESSAGE_ID = "error.sortInfoValidator.conflictingCriteria";

    /**
     * The message identifier of the {@link javax.faces.application.FacesMessage} to be created if the value to validate
     * contains a sort info with an empty sort criterion.
     */
    public static final String EMPTY_CRITERION_MESSAGE_ID = "error.sortInfoValidator.emptyCriterion";

    @Override
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
        if (context == null || component == null) {
            throw new IllegalArgumentException();
        }
        if (value != null) {
            if (value instanceof List) {
                try {
                    List sortInfos = (List) value;
                    List<String> criteria = new ArrayList<String>();
                    for (Object sortInfo : sortInfos) {
                        String criterion = null;
                        if (sortInfo instanceof SortInfo) {
                            criterion = ((SortInfo) sortInfo).getSortColumn();
                        } else {
                            // assume it's a map
                            SortInfo sortInfoValue = SortInfo.asSortInfo((Map) sortInfo);
                            if (sortInfoValue == null) {
                                throw new ValidatorException(MessageFactory.getMessage(context,
                                        INVALID_VALUE_MESSAGE_ID));
                            }
                            criterion = sortInfoValue.getSortColumn();
                        }
                        if (criterion == null || StringUtils.isEmpty(criterion.trim())) {
                            throw new ValidatorException(MessageFactory.getMessage(context, EMPTY_CRITERION_MESSAGE_ID));
                        }
                        if (criteria.contains(criterion)) {
                            throw new ValidatorException(MessageFactory.getMessage(context,
                                    CONFLICTING_CRITERIA_MESSAGE_ID, criterion));
                        } else {
                            criteria.add(criterion);
                        }
                    }
                } catch (ClassCastException e) {
                    throw new ValidatorException(MessageFactory.getMessage(context, INVALID_VALUE_MESSAGE_ID));
                }
            }
        }
    }
}