com.googlecode.wicket.kendo.ui.repeater.dataview.DataProviderBehavior.java Source code

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Here is the source code for com.googlecode.wicket.kendo.ui.repeater.dataview.DataProviderBehavior.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package com.googlecode.wicket.kendo.ui.repeater.dataview;

import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.apache.wicket.Application;
import org.apache.wicket.behavior.AbstractAjaxBehavior;
import org.apache.wicket.markup.repeater.data.IDataProvider;
import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.IRequestParameters;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.http.WebResponse;

import com.googlecode.wicket.jquery.core.renderer.ITextRenderer;
import com.googlecode.wicket.jquery.core.template.IJQueryTemplate;
import com.googlecode.wicket.jquery.core.utils.BuilderUtils;
import com.googlecode.wicket.jquery.core.utils.ListUtils;

/**
 * Provides the {@link IDataProvider} data source {@link AbstractAjaxBehavior}
 *
 * @param <T> the type of the model object
 * @author Sebastien Briquet - sebfz1
 */
public class DataProviderBehavior<T> extends AbstractAjaxBehavior {
    private static final long serialVersionUID = 1L;

    private final IDataProvider<T> provider;
    private final ITextRenderer<? super T> renderer;
    private final IJQueryTemplate template;

    /**
     * Constructor
     *
     * @param provider the {@link IDataProvider}
     */
    public DataProviderBehavior(final IDataProvider<T> provider, ITextRenderer<? super T> renderer) {
        this(provider, renderer, null);
    }

    public DataProviderBehavior(final IDataProvider<T> provider, ITextRenderer<? super T> renderer,
            IJQueryTemplate template) {
        this.provider = provider;
        this.renderer = renderer;
        this.template = template;
    }

    /**
     * Gets the property set that should be appended to the JSON response.<br/>
     * The value corresponding to the property is retrieved from the {@link ITextRenderer#getText(Object, String)}
     *
     * @return the property list
     */
    protected List<String> getProperties() {
        if (this.template != null) {
            return ListUtils.exclude(this.template.getTextProperties(), this.renderer.getFields()); // #198
        }

        return Collections.emptyList();
    }

    @Override
    public void onRequest() {
        final RequestCycle requestCycle = RequestCycle.get();
        final IRequestParameters parameters = requestCycle.getRequest().getQueryParameters();
        final int first = parameters.getParameterValue("skip").toInt(0);
        final int count = parameters.getParameterValue("take").toInt(Integer.MAX_VALUE);

        requestCycle.scheduleRequestHandlerAfterCurrent(this.newRequestHandler(first, count));
    }

    /**
     * Gets the new {@link IRequestHandler} that will respond the data in a json format
     *
     * @param first the first row number
     * @param count the count of rows
     * @return a new {@code IRequestHandler}
     */
    private IRequestHandler newRequestHandler(final int first, final int count) {
        return new DataProviderRequestHandler(first, count);
    }

    /**
     * Provides the {@link IRequestHandler}
     */
    protected class DataProviderRequestHandler implements IRequestHandler {
        private final int first;
        private final int count;

        public DataProviderRequestHandler(int first, int count) {
            this.first = first;
            this.count = count;
        }

        @Override
        public void respond(final IRequestCycle requestCycle) {
            WebResponse response = (WebResponse) requestCycle.getResponse();

            final String encoding = Application.get().getRequestCycleSettings().getResponseRequestEncoding();
            response.setContentType("application/json; charset=" + encoding);
            response.disableCaching();

            // final long size = provider.size();
            final Iterator<? extends T> iterator = provider.iterator(first, count);

            // builds JSON result //
            StringBuilder builder = new StringBuilder("[");

            if (iterator != null) {
                for (int index = 0; iterator.hasNext(); index++) {
                    T object = iterator.next();

                    if (index > 0) {
                        builder.append(", ");
                    }

                    builder.append("{ ");

                    // ITextRenderer //
                    builder.append(renderer.render(object));

                    // Additional properties (like template properties) //
                    List<String> properties = DataProviderBehavior.this.getProperties();

                    for (String property : properties) {
                        builder.append(", ");
                        BuilderUtils.append(builder, property, renderer.getText(object, property));
                    }

                    builder.append(" }");
                }
            }

            builder.append(" ]");

            response.write(builder);
        }

        @Override
        public void detach(final IRequestCycle requestCycle) {
            provider.detach();
        }
    }
}