XmlMethodCallSerializer.java

/**
 * \package com.bluevia.android.commons.parser.xmlrpc This package contains the classes in order to manage and parse/serialize xml-rpc calls and responses using Bluevia API.
 */
package com.bluevia.android.commons.parser.xmlrpc;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import org.xmlpull.v1.XmlSerializer;

import android.util.Log;
import android.util.Xml;

import com.bluevia.android.commons.Entity;
import com.bluevia.android.commons.data.xmlrpc.MethodCall;
import com.bluevia.android.commons.parser.ISerializer;
import com.bluevia.android.commons.parser.SerializeException;
import com.bluevia.android.commons.parser.xml.XmlConstants;


/**
 * Xml serializer for RPC MethodCall entities.
 */
public abstract class XmlMethodCallSerializer implements ISerializer {

	private static final String TAG = "XmlMethodCallSerializer";

	public abstract ByteArrayOutputStream serialize(Entity entity) throws SerializeException;

	/**
	 * This function serializes the methodCall tag.
	 * 
	 * @param entity the entity to serialize
	 * @param out out the outputstream to write the serialization result to
	 * @param apiUri the specific API Uri
	 * @param schemaLocation the specific Schema Location for the API
	 * @throws SerializeException 
	 */
	protected void serialize(Entity entity, OutputStream out, String apiUri, String schemaLocation) throws SerializeException {
		
		if (!(entity instanceof MethodCall)) {
			throw new SerializeException("Attempted to parse unsupported entity type");
		}
		
		try {
		
		XmlSerializer serializer = Xml.newSerializer();
		serializer.setOutput(out, "UTF-8");
		serializer.startDocument(null, null);

		// Root tag
		serializer.setPrefix(XmlConstants.UCTRPC, XmlConstants.NS_RPC_COMMON_API_URI);
		serializer.setPrefix(XmlConstants.RPC, XmlConstants.NS_RPC_DEFINITION_URI);
		serializer.setPrefix(XmlConstants.TNS, apiUri);
		serializer.setPrefix(XmlConstants.XSI, XmlConstants.NS_XML_SCHEMA_INSTANCE);
		serializer.startTag(apiUri, XmlConstants.XSD_RPC_METHOD_CALL);
		serializer.attribute(XmlConstants.NS_XML_SCHEMA_INSTANCE, XmlConstants.XSD_TEXTYPE_SCHEMALOCATION, schemaLocation);

		//Serialize MethodCall Attributes
		serializeMethodCallAttributes((MethodCall) entity, serializer, apiUri);

		// Message Params
		if (((MethodCall) entity).getParamsEntity() != null)
		{
			serializer.startTag(apiUri, XmlConstants.XSD_RPC_PARAMS);
			serializeParams(((MethodCall) entity).getParamsEntity(), serializer);
			serializer.endTag(apiUri, XmlConstants.XSD_RPC_PARAMS);
		}

		// End root tag
		serializer.endTag(apiUri, XmlConstants.XSD_RPC_METHOD_CALL);

		serializer.endDocument();;
		serializer.flush();
		} catch (IOException e){
			throw new SerializeException(e);
		}
	}

	/**
	 * Serializes the common attributes of the MethodCall
	 * 
	 * @param methodCall the MethodCall entity
	 * @param serializer the serializer
	 * @throws IOException
	 * @throws SerializeException
	 */
	private void serializeMethodCallAttributes(MethodCall methodCall, XmlSerializer serializer, String apiUri) throws IOException, SerializeException {

		//Id (optional)
		if (methodCall.getId() != null){
			serializer.startTag(XmlConstants.NS_RPC_DEFINITION_URI, XmlConstants.XSD_RPC_ID_ATTR);
			serializer.text(methodCall.getId());
			serializer.endTag(XmlConstants.NS_RPC_DEFINITION_URI, XmlConstants.XSD_RPC_ID_ATTR);
		}

		//Version (mandatory)
		if (methodCall.getVersion() == null)
			throw new SerializeException("Version attribute cannot be null");
		serializer.startTag(XmlConstants.NS_RPC_DEFINITION_URI, XmlConstants.XSD_RPC_VERSION_ATTR);
		serializer.text(methodCall.getVersion());
		serializer.endTag(XmlConstants.NS_RPC_DEFINITION_URI, XmlConstants.XSD_RPC_VERSION_ATTR);

		//Method (mandatory)
		Log.d(TAG, "getting Method:" + methodCall.getMethod());
		if (methodCall.getMethod() == null)
			throw new SerializeException("Method attribute cannot be null");
		serializer.startTag(apiUri, XmlConstants.XSD_RPC_METHOD_ATTR);
		serializer.text(methodCall.getMethod());
		serializer.endTag(apiUri, XmlConstants.XSD_RPC_METHOD_ATTR);
	}

	/**
	 * Abstract function to serialize the params of the Method Call
	 * 
	 * @param entity the specific entity to serialize
	 * @param serializer the serializer
	 * @throws IOException
	 * @throws SerializeException
	 */
	protected abstract void serializeParams(Entity entity, XmlSerializer serializer) throws IOException, SerializeException;

}