FiltersUtils.java

/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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 org.opencastproject.index.service.util;

import org.opencastproject.index.service.resources.list.api.ResourceListFilter;
import org.opencastproject.index.service.resources.list.api.ResourceListFilter.SourceType;
import org.opencastproject.index.service.resources.list.query.AbstractListFilter;
import org.opencastproject.util.data.Option;

import org.apache.commons.lang3.StringUtils;

/**
 * Utility class providing helpers for all operations related to the filters.
 */
public final class FiltersUtils {

  private FiltersUtils() {

  }

  /**
   * Create a new {@link ResourceListFilter} following the parameters given
   * 
   * @param value
   *          The value of the filter wrapped in an {@link Option}. Can be {@link Option#none()}
   * @param name
   *          The name of the filter, required.
   * @param label
   *          The label of the filter, required.
   * @param type
   *          the {@link SourceType}
   * @param valuesListName
   *          The name of the list from a list provider providing the possible values wrapped in a {@link Option}.Can be
   *          {@link Option#none()}
   * @throws IllegalArgumentException
   *           if the name, label or type is null or empty.
   * @return a new {@link ResourceListFilter} with the parameters given
   */
  public static <A> ResourceListFilter<A> generateFilter(final Option<A> value, final String name, final String label,
          final SourceType type, final Option<String> valuesListName) throws IllegalArgumentException {
    if (StringUtils.isBlank(name) || StringUtils.isBlank(label) || type == null)
      throw new IllegalArgumentException("The filter label, name or type must not be null!");

    return new AbstractListFilter<A>(value) {

      @Override
      public String getName() {
        return name;
      }

      @Override
      public String getLabel() {
        return label;
      }

      @Override
      public Option<String> getValuesListName() {
        return valuesListName != null ? valuesListName : Option.<String> none();
      }

      @Override
      public SourceType getSourceType() {
        return type;
      }

    };
  }
}