com.vaynberg.wicket.select2.Select2GroupedMultiChoice Maven / Gradle / Ivy

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/*
 * Copyright 2017 Justin Graham
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with
 * the License. You may obtain a copy of the License in the LICENSE file, or 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 com.vaynberg.wicket.select2;

import org.apache.wicket.model.IModel;
import org.json.JSONException;
import org.json.JSONWriter;

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

/**
 * @author Justin Graham
 * @since 4/19/17
 */
public class Select2GroupedMultiChoice extends Select2MultiChoice {

    /** The key to group values which have null or empty groups */
    private static final String UNGROUPED = "UNGROUPED";

    public Select2GroupedMultiChoice(String id, IModel> model, ChoiceProvider provider) {
        super(id, model, provider);
    }

    public Select2GroupedMultiChoice(String id, IModel> model) {
        super(id, model);
    }

    public Select2GroupedMultiChoice(String id) {
        super(id);
    }

    /**
     * Handles building the grouped JSON structure to provide to Select2
     *
     * {@code
     * {
     *   "results": [
     *     {
     *       "text": "group1",
     *       "children": [
     *         {
     *           "id": 1,
     *           "text": "Some Text"
     *         },
     *         {
     *           "id": 2,
     *           "text": "Some More Text"
     *         }
     *       ]
     *     },
     *     {
     *       "text": "group2",
     *       "children": [
     *         {
     *           "id": 3,
     *           "text": "Another Item"
     *         }
     *       ]
     *     }
     *   ],
     *   "more": true
     * }
     * }
     *
     * @param json the writer to append the JSON nodes to
     * @param response Iterable collection of objects extending {@link GroupedValue}
     * @throws JSONException if the response contains malformed JSON
     */
    @Override
    protected void addValues(final JSONWriter json, final Iterable response) throws JSONException {
        final Map> groupedItems = groupItems(response);
        for (Map.Entry> entry : groupedItems.entrySet()) {
            if (UNGROUPED.equals(entry.getKey())) {
                super.addValues(json, entry.getValue());
                continue;
            }
            json.object().key("text").value(entry.getKey()).key("children").array();
            super.addValues(json, entry.getValue());
            json.endArray().endObject();
        }
    }

    /**
     * Groups the {@link Iterable} on the {@link GroupedValue#group}. If the value's group is null or
     * empty its added as {@link Select2GroupedMultiChoice#UNGROUPED}
     *
     * @param response Iterable collection of objects extending {@link GroupedValue}
     * @return the sorted values
     */
    protected Map> groupItems(final Iterable response) {
        final Map> groupedItems = new HashMap>();
        for (final T item : response) {
            final String group = item.getGroup();
            final String key = (group == null || group.isEmpty()) ? UNGROUPED : group;
            if (groupedItems.containsKey(key)) {
                groupedItems.get(key).add(item);
                continue;
            }
            groupedItems.put(key, new ArrayList() {{
                add(item);
            }});
        }
        return groupedItems;
    }
}