com.vaynberg.wicket.select2.Select2MultiChoice.java Source code

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Here is the source code for com.vaynberg.wicket.select2.Select2MultiChoice.java

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/*
 * Copyright 2012 Igor Vaynberg
 * 
 * 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 java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;

import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.markup.head.OnDomReadyHeaderItem;
import org.apache.wicket.model.IModel;
import org.apache.wicket.util.string.Strings;
import org.json.JSONException;

import com.vaynberg.wicket.select2.json.JsonBuilder;

/**
 * Multi-select Select2 component. Should be attached to a {@code <input type='hidden'/>} element.
 * 
 * @author igor
 * 
 * @param <T>
 *            type of choice object
 */
public class Select2MultiChoice<T> extends AbstractSelect2Choice<T, Collection<T>> {

    public Select2MultiChoice(String id, IModel<Collection<T>> model, ChoiceProvider<T> provider) {
        super(id, model, provider);
    }

    public Select2MultiChoice(String id, IModel<Collection<T>> model) {
        super(id, model);
    }

    public Select2MultiChoice(String id) {
        super(id);
    }

    @Override
    protected void convertInput() {

        String input = getWebRequest().getRequestParameters().getParameterValue(getInputName()).toString();

        final Collection<T> choices;
        if (Strings.isEmpty(input)) {
            choices = new ArrayList<T>();
        } else {
            choices = getProvider().toChoices(Arrays.asList(input.split(",")));
        }

        setConvertedInput(choices);
    }

    @Override
    public void updateModel() {
        Collection<T> choices = getModelObject();
        Collection<T> selection = getConvertedInput();

        if (choices == null) {
            setModelObject(selection);
        } else {
            choices.clear();
            choices.addAll(selection);
            setModelObject(choices);
        }
    }

    @Override
    protected void onInitialize() {
        super.onInitialize();
        getSettings().setMultiple(true);
    }

    @Override
    protected String getModelValue() {
        Collection<T> values = getModelObject();

        // if values is null or empty set value attribute to an empty string rather then '[]' which does not make sense
        if (values == null || values.isEmpty()) {
            return "";
        }

        return super.getModelValue();
    }

    @Override
    protected void renderInitializationScript(IHeaderResponse response) {
        Collection<? extends T> choices = hasRawInput() ? getConvertedInput() : getModelObject();
        if (choices != null && !choices.isEmpty()) {

            JsonBuilder selection = new JsonBuilder();

            try {
                selection.array();
                for (T choice : choices) {
                    selection.object();
                    getProvider().toJson(choice, selection);
                    selection.endObject();
                }
                selection.endArray();
            } catch (JSONException e) {
                throw new RuntimeException("Error converting model object to Json", e);
            }

            response.render(OnDomReadyHeaderItem
                    .forScript(JQuery.execute("$('#%s').select2('data', %s);", getMarkupId(), selection.toJson())));
        }
    }

}