TDS.Shared.Messages.MessageJson.java Source code

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Here is the source code for TDS.Shared.Messages.MessageJson.java

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/*******************************************************************************
 * Educational Online Test Delivery System 
 * Copyright (c) 2014 American Institutes for Research
 *   
 * Distributed under the AIR Open Source License, Version 1.0 
 * See accompanying file AIR-License-1_0.txt or at
 * http://www.smarterapp.org/documents/American_Institutes_for_Research_Open_Source_Software_License.pdf
 ******************************************************************************/
package TDS.Shared.Messages;

import java.io.IOException;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang.StringUtils;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonGenerator;

import TDS.Shared.Data.ReturnStatus;
import TDS.Shared.Exceptions.ReturnStatusException;

// Example:
// {"c_l":"ESN",
// "c_a":[{"c":"Global",
// "m_a":[{"id":10884,
// "m":"Global.Path.Help",
// "t_a":[{"t":"..\/Projects\/Oregon\/Help\/help.html",
// "l":"ENU"}]
// },
// {"id":11690,
// "m":"Messages.Label.XHRError",
// "t_a":[{"t":"Select Yes to try again or No to log out.",
// "l":"ENU"}]
// }
// ]
// }
// ]
// }

public class MessageJson {

    private final MessageSystem _messageSystem;
    private final String _language;
    private final String _subject;
    private final String _grade;

    public MessageJson(MessageSystem messageSystem) {
        _messageSystem = messageSystem;
        _language = null;
        _subject = null;
        _grade = null;
    }

    public MessageJson(MessageSystem messageSystem, String language) {
        _messageSystem = messageSystem;
        _language = language;
        _subject = null;
        _grade = null;
    }

    public MessageJson(MessageSystem messageSystem, String language, String subject, String grade) {
        _messageSystem = messageSystem;
        _language = language;
        _subject = subject;
        _grade = grade;
    }

    // / <summary>
    // / Write out the context group.
    // / </summary>
    private void writeContextElement(MessageContext messageContext, JsonGenerator jsonWriter)
            throws JsonGenerationException, IOException {
        jsonWriter.writeStartObject(); // {
        jsonWriter.writeStringField("c", messageContext.getName()); // "c": "name"
        jsonWriter.writeFieldName("m_a"); // "m_a":
        jsonWriter.writeStartArray(); // [
        List<Message> messages = messageContext.getMessages();
        for (Message message : messages) {
            writeMessageElement(message, jsonWriter);
        }
        jsonWriter.writeEndArray(); // ]
        jsonWriter.writeEndObject(); // }
    }

    // / <summary>
    // / Write out the message id and key.
    // / </summary>
    private void writeMessageElement(Message message, JsonGenerator jsonWriter)
            throws JsonGenerationException, IOException {
        // {"id":10884,
        // "m":"Global.Path.Help",
        // "t_a":[{"t":"..\/Projects\/Oregon\/Help\/help.html",
        // "l":"ENU"}]
        // }
        jsonWriter.writeStartObject(); // {
        jsonWriter.writeNumberField("id", message.getMessageId());
        jsonWriter.writeStringField("m", message.getMessageKey());

        jsonWriter.writeFieldName("t_a"); // "t_a":
        jsonWriter.writeStartArray(); // [

        List<MessageTranslation> translations;

        // if there is no language specified they get all translations
        if (StringUtils.isEmpty(_language)) {
            translations = message.getTranslations();
        } else {
            // if a language is provided then find the best language and only
            // include that
            MessageTranslation defaultTranslation = message.getTranslation(_language, _subject, _grade);
            translations = new ArrayList<MessageTranslation>();
            translations.add(defaultTranslation);
        }

        for (MessageTranslation translation : translations) {
            writeTranslationElement(translation, jsonWriter);
        }

        jsonWriter.writeEndArray(); // ]
        jsonWriter.writeEndObject(); // }
    }

    // / <summary>
    // / Write out the translations for a key.
    // / </summary>
    private void writeTranslationElement(MessageTranslation translation, JsonGenerator jsonWriter)
            throws IOException {
        // {"t":"..\/Projects\/Oregon\/Help\/help.html",
        // "l":"ENU"}
        jsonWriter.writeStartObject(); // {
        jsonWriter.writeStringField("t", translation.getText());
        jsonWriter.writeStringField("l", translation.getLanguage());

        if (translation.getSubject() != null)
            jsonWriter.writeStringField("s", translation.getSubject());
        if (translation.getGrade() != null)
            jsonWriter.writeStringField("g", translation.getGrade());
        jsonWriter.writeEndObject(); // }
    }

    public String create(ContextType contextType, List<String> contexts) throws ReturnStatusException {
        MessageContextType messageContextType = null;
        StringWriter sw = new StringWriter();
        JsonFactory jsonFactory = new JsonFactory();
        JsonGenerator jsonWriter;

        try {
            if (_messageSystem != null) {
                messageContextType = _messageSystem.getMessageContextType(contextType);
            }

            if (messageContextType == null)
                return "{}";

            jsonWriter = jsonFactory.createGenerator(sw);
            jsonWriter.writeStartObject();
            jsonWriter.writeStringField("c_l", _language); // "c_l": _language
            jsonWriter.writeFieldName("c_a"); // "c_a" :
            jsonWriter.writeStartArray(); // [

            for (String context : contexts) {
                MessageContext messageContext = messageContextType.getContext(context);
                writeContextElement(messageContext, jsonWriter);
            }

            jsonWriter.writeEndArray(); // ]
            jsonWriter.writeEndObject(); // }

            jsonWriter.close();
            sw.close();
        } catch (IOException e) {
            ReturnStatus rs = new ReturnStatus("failed", "Serialization failed: " + e.getMessage());
            throw new ReturnStatusException(rs);
        }

        return sw.getBuffer().toString();
    }

    // / <summary>
    // / Create a JSON String of all the messages.
    // / </summary>
    public String create() throws ReturnStatusException {
        StringWriter sw = new StringWriter();
        JsonFactory jsonFactory = new JsonFactory();
        JsonGenerator jsonWriter;

        try {
            if (_messageSystem == null)
                return "{}";

            jsonWriter = jsonFactory.createGenerator(sw);
            jsonWriter.writeStartObject();

            jsonWriter.writeStringField("c_l", _language); // "c_l": _language
            jsonWriter.writeFieldName("c_a"); // "c_a" :
            jsonWriter.writeStartArray(); // [

            // get all the message contexts across all the context types
            List<MessageContext> messageContexts = new ArrayList<MessageContext>();
            for (MessageContextType contextType : _messageSystem.getContextTypes()) {
                messageContexts.addAll(contextType.getContexts());
            }

            for (MessageContext messageContext : messageContexts) {
                writeContextElement(messageContext, jsonWriter);
            }

            jsonWriter.writeEndArray(); // ]
            jsonWriter.writeEndObject(); // }

            jsonWriter.close();
            sw.close();
        } catch (IOException e) {
            ReturnStatus rs = new ReturnStatus("failed", "Serialization failed: " + e.getMessage());
            throw new ReturnStatusException(rs);
        }

        return sw.getBuffer().toString();
    }
}