com.googlecode.wicket.jquery.ui.form.autocomplete.AutoCompleteSourceBehavior.java Source code

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Here is the source code for com.googlecode.wicket.jquery.ui.form.autocomplete.AutoCompleteSourceBehavior.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.jquery.ui.form.autocomplete;

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

import org.apache.wicket.Application;
import org.apache.wicket.ajax.AbstractDefaultAjaxBehavior;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.http.WebResponse;

import com.googlecode.wicket.jquery.core.Options;
import com.googlecode.wicket.jquery.core.renderer.ITextRenderer;

/**
 * Provides the {@link AbstractDefaultAjaxBehavior} for the {@link AutoCompleteTextField}
 *
 * @author Sebastien Briquet - sebfz1
 *
 * @param <T> the type of the model object
 */
abstract class AutoCompleteSourceBehavior<T> extends AbstractDefaultAjaxBehavior {
    private static final long serialVersionUID = 1L;
    private static final String QUERY = "term";

    private final ITextRenderer<? super T> renderer;

    public AutoCompleteSourceBehavior(ITextRenderer<? super T> renderer) {
        this.renderer = renderer;
    }

    /**
     * Gets choices matching the provided input
     * @param input String that represent the query
     * @return the list of choices
     */
    protected abstract List<T> getChoices(String input);

    /**
     * Gets the property list that should be appended to the JSON response. The value corresponding to the property is retrieved from the {@link ITextRenderer#getText(Object, String)}
     * @return the property list
     */
    protected List<String> getProperties() {
        return Collections.emptyList();
    }

    @Override
    protected void respond(AjaxRequestTarget target) {
        final RequestCycle requestCycle = RequestCycle.get();
        final String value = requestCycle.getRequest().getQueryParameters().getParameterValue(QUERY).toString();

        final IRequestHandler handler = this.newRequestHandler(value);
        requestCycle.scheduleRequestHandlerAfterCurrent(handler);
    }

    /**
     * Gets a new {@link IRequestHandler} that will call {@link #getChoices(String)} and will build be JSON response corresponding to the specified 'input' argument.
     * @param input user input
     * @return a new {@link IRequestHandler}
     */
    private IRequestHandler newRequestHandler(final String input) {
        return new IRequestHandler() {
            @Override
            public void respond(final IRequestCycle requestCycle) {
                WebResponse response = (WebResponse) requestCycle.getResponse();

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

                List<T> choices = AutoCompleteSourceBehavior.this.getChoices(input);
                List<String> properties = AutoCompleteSourceBehavior.this.getProperties();

                if (choices != null) {
                    StringBuilder builder = new StringBuilder("[ ");

                    int index = 0;
                    for (T choice : choices) {
                        if (index++ > 0) {
                            builder.append(", ");
                        }

                        builder.append("{ ");
                        builder.append(Options.QUOTE).append("id").append(Options.QUOTE).append(": ")
                                .append(Options.QUOTE).append(Integer.toString(index))
                                .append(Options.QUOTE); /* id is a reserved word */
                        builder.append(", ");
                        builder.append(Options.QUOTE).append("value").append(Options.QUOTE).append(": ")
                                .append(Options.QUOTE).append(renderer.getText(choice))
                                .append(Options.QUOTE); /* value is a reserved word */

                        if (properties != null) {
                            for (String property : properties) {
                                builder.append(", ");
                                builder.append(Options.QUOTE).append(property).append(Options.QUOTE).append(": ")
                                        .append(Options.QUOTE).append(renderer.getText(choice, property))
                                        .append(Options.QUOTE);
                            }
                        }

                        builder.append(" }");
                    }

                    builder.append(" ]");

                    response.write(builder);
                }
            }

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