de.spartusch.nasfvi.client.SuggestRequest.java Source code

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Here is the source code for de.spartusch.nasfvi.client.SuggestRequest.java

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/*
 * Copyright 2011 Stefan Partusch
 *
 * Licensed 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 de.spartusch.nasfvi.client;

import java.util.ArrayList;

import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.RequestException;
import com.google.gwt.http.client.Response;
import com.google.gwt.http.client.URL;
import com.google.gwt.json.client.JSONArray;
import com.google.gwt.json.client.JSONParser;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.SuggestOracle;

/**
 * A request for suggestions from the server. When run this class requests
 * suggestions from the server and provides the suggestions to a {@link
 * com.google.gwt.user.client.ui.SuggestOracle SuggestOracle}.
 * @author Stefan Partusch
 * @see {@link Suggestions}
 *
 */
public class SuggestRequest extends Timer implements RequestCallback {
    private String url;
    private SuggestOracle.Request soRequest;
    private SuggestOracle.Callback soCallback;

    /**
     * Creates a new request for suggestions from the server.
     * @param url URL to request suggestions from
     * @param soRequest Query to request suggestions for
     * @param soCallback Callback to provide retrieved suggestions
     * to a SuggestOracle
     */
    public SuggestRequest(final String url, final SuggestOracle.Request soRequest,
            final SuggestOracle.Callback soCallback) {
        this.url = url;
        this.soRequest = soRequest;
        this.soCallback = soCallback;
    }

    @Override
    public final void run() {
        try {
            String getUrl = url + URL.encodeQueryString(soRequest.getQuery());
            RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, getUrl);
            builder.setCallback(this);
            builder.send();
        } catch (RequestException e) {
            Main.displayError(e.getLocalizedMessage(), e.toString());
        }
    }

    @Override
    public final void onError(final Request request, final Throwable exception) {
        Main.displayError(exception.getLocalizedMessage(), exception.toString());
    }

    @Override
    public final void onResponseReceived(final Request request, final Response response) {
        if (response.getStatusCode() == Response.SC_OK) {
            ArrayList<Suggestions.Sentence> suggestions = new ArrayList<Suggestions.Sentence>();

            JSONArray arr = JSONParser.parseLenient(response.getText()).isArray();
            JSONArray sentences = arr.get(1).isArray();

            for (int i = 0; i < sentences.size(); i++) {
                suggestions.add(new Suggestions.Sentence(sentences.get(i)));
            }

            soCallback.onSuggestionsReady(soRequest, new SuggestOracle.Response(suggestions));
        }
    }
}