MqttGenericBindingProvider.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.mqtt.internal;

import org.apache.commons.lang.StringUtils;
import org.openhab.binding.mqtt.MqttBindingProvider;
import org.openhab.core.binding.BindingChangeListener;
import org.openhab.core.binding.BindingProvider;
import org.openhab.core.items.Item;
import org.openhab.io.transport.mqtt.MqttService;
import org.openhab.model.item.binding.AbstractGenericBindingProvider;
import org.openhab.model.item.binding.BindingConfigParseException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * MQTT Binding provider implementation. Creates MQTT configuration for OpenHAB
 * items.
 *
 * @author Davy Vanherbergen
 * @since 1.3.0
 */
public class MqttGenericBindingProvider extends AbstractGenericBindingProvider implements MqttBindingProvider {

    private static final Logger logger = LoggerFactory.getLogger(MqttGenericBindingProvider.class);

    private MqttService mqttService;

    @Override
    public String getBindingType() {
        return "mqtt";
    }

    @Override
    public void validateItemType(Item item, String bindingConfig) throws BindingConfigParseException {
        // all Item types are accepted for now..
        return;
    }

    @Override
    public void processBindingConfiguration(String context, Item item, String bindingConfig)
            throws BindingConfigParseException {
        super.processBindingConfiguration(context, item, bindingConfig);

        final String itemName = item.getName();
        logger.trace("Starting to load MQTT config for item {}", itemName);

        if (StringUtils.isEmpty(bindingConfig)) {
            throw new BindingConfigParseException("Missing mqtt binding configuration for item " + itemName);
        }

        final MqttItemConfig itemConfig = new MqttItemConfig(item, bindingConfig);

        // register all message consumers
        for (MqttMessageSubscriber subscriber : itemConfig.getMessageSubscribers()) {
            subscriber.setItemName(item.getName());
            mqttService.registerMessageConsumer(subscriber.getBroker(), subscriber);
        }

        // add binding change listener to clean up message consumers on item removal
        addBindingChangeListener(new BindingChangeListener() {

            @Override
            public void bindingChanged(BindingProvider provider, String changedItemName) {
                if (itemName.equals(changedItemName) && !provider.providesBindingFor(itemName)) {
                    logger.debug("Removing message consumers for item {}", itemName);
                    for (MqttMessageSubscriber subscriber : itemConfig.getMessageSubscribers()) {
                        mqttService.unregisterMessageConsumer(subscriber.getBroker(), subscriber);
                    }
                    removeBindingChangeListener(this);
                }
            }

            @Override
            public void allBindingsChanged(BindingProvider provider) {
                if (!provider.providesBindingFor(itemName)) {
                    logger.debug("Removing message consumers for item {}", itemName);
                    for (MqttMessageSubscriber subscriber : itemConfig.getMessageSubscribers()) {
                        mqttService.unregisterMessageConsumer(subscriber.getBroker(), subscriber);
                    }
                    removeBindingChangeListener(this);
                }
            }
        });

        // register all message producers
        for (MqttMessagePublisher publisher : itemConfig.getMessagePublishers()) {
            publisher.setItemName(item.getName());
            mqttService.registerMessageProducer(publisher.getBroker(), publisher);
        }

        // add binding change listener to clean up message publishers on item
        // removal
        addBindingChangeListener(new BindingChangeListener() {

            @Override
            public void bindingChanged(BindingProvider provider, String changedItemName) {
                if (itemName.equals(changedItemName) && !provider.providesBindingFor(itemName)) {
                    logger.debug("Removing message publishers for item {}", itemName);
                    for (MqttMessagePublisher publisher : itemConfig.getMessagePublishers()) {
                        mqttService.unregisterMessageProducer(publisher.getBroker(), publisher);
                    }
                    removeBindingChangeListener(this);
                }
            }

            @Override
            public void allBindingsChanged(BindingProvider provider) {
                if (!provider.providesBindingFor(itemName)) {
                    logger.debug("Removing message publishers for item {}", itemName);
                    for (MqttMessagePublisher publisher : itemConfig.getMessagePublishers()) {
                        mqttService.unregisterMessageProducer(publisher.getBroker(), publisher);
                    }
                    removeBindingChangeListener(this);
                }
            }
        });

        addBindingConfig(item, itemConfig);
    }

    @Override
    public MqttItemConfig getItemConfig(String itemName) {
        return (MqttItemConfig) bindingConfigs.get(itemName);
    }

    /**
     * Setter for Declarative Services. Adds the MqttService instance.
     * 
     * @param mqttService
     *            Service.
     */
    public void setMqttService(MqttService mqttService) {
        this.mqttService = mqttService;
    }

    /**
     * Unsetter for Declarative Services.
     * 
     * @param mqttService
     *            Service to remove.
     */
    public void unsetMqttService(MqttService mqttService) {
        this.mqttService = null;
    }

}