org.jivesoftware.smackx.pubsub.Item Maven / Gradle / Ivy
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/**
*
* Copyright the original author or authors
*
* 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 org.jivesoftware.smackx.pubsub;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.util.XmlStringBuilder;
import org.jivesoftware.smackx.pubsub.form.ConfigureForm;
import org.jivesoftware.smackx.pubsub.provider.ItemProvider;
/**
* This class represents an item that has been, or will be published to a
* PubSub node. An Item has several properties that are dependent
* on the configuration of the node to which it has been or will be published.
*
*
* An Item received from a node (via {@link LeafNode#getItems()} or {@link LeafNode#addItemEventListener(org.jivesoftware.smackx.pubsub.listener.ItemEventListener)}
*
*
* - Will always have an id (either user or server generated) unless node configuration has both
* {@link ConfigureForm#isPersistItems()} and {@link ConfigureForm#isDeliverPayloads()}set to false.
*
- Will have a payload if the node configuration has {@link ConfigureForm#isDeliverPayloads()} set
* to true, otherwise it will be null.
*
*
*
* An Item created to send to a node (via {@link LeafNode#publish()} or {@link LeafNode#publish()}
*
*
* - The id is optional, since the server will generate one if necessary, but should be used if it is
* meaningful in the context of the node. This value must be unique within the node that it is sent to, since
* resending an item with the same id will overwrite the one that already exists if the items are persisted.
*
- Will require payload if the node configuration has {@link ConfigureForm#isDeliverPayloads()} set
* to true.
*
*
*
* To customise the payload object being returned from the {@link PayloadItem#getPayload()} method, you can
* add a custom parser as explained in {@link ItemProvider}.
*
*
* @author Robin Collier
*/
public class Item extends NodeExtension {
public enum ItemNamespace {
pubsub(PubSubElementType.ITEM),
event(PubSubElementType.ITEM_EVENT),
;
private final PubSubElementType type;
ItemNamespace(PubSubElementType type) {
this.type = type;
}
public static ItemNamespace fromXmlns(String xmlns) {
for (ItemNamespace itemNamespace : ItemNamespace.values()) {
if (itemNamespace.type.getNamespace().getXmlns().equals(xmlns)) {
return itemNamespace;
}
}
throw new IllegalArgumentException("Invalid item namespace: " + xmlns);
}
}
private final String itemId;
/**
* Create an empty Item with no id. This is a valid item for nodes which are configured
* so that {@link ConfigureForm#isDeliverPayloads()} is false. In most cases an id will be generated by the server.
* For nodes configured with {@link ConfigureForm#isDeliverPayloads()} and {@link ConfigureForm#isPersistItems()}
* set to false, no Item is sent to the node, you have to use the {@link LeafNode#publish()}
* method in this case.
*/
public Item() {
this(ItemNamespace.pubsub, null, null);
}
/**
* Create an Item with an id but no payload. This is a valid item for nodes which are configured
* so that {@link ConfigureForm#isDeliverPayloads()} is false.
*
* @param itemId The id if the item. It must be unique within the node unless overwriting and existing item.
* Passing null is the equivalent of calling {@link #Item()}.
*/
public Item(String itemId) {
this(ItemNamespace.pubsub, itemId, null);
}
/**
* Create an Item with an id but no payload. This is a valid item for nodes which are configured
* so that {@link ConfigureForm#isDeliverPayloads()} is false.
*
* @param itemNamespace the namespace of the item.
* @param itemId The id if the item. It must be unique within the node unless overwriting and existing item.
* Passing null is the equivalent of calling {@link #Item()}.
*/
public Item(ItemNamespace itemNamespace, String itemId) {
this(itemNamespace, itemId, null);
}
/**
* Create an Item with an id and a node id.
*
* Note: This is not valid for publishing an item to a node, only receiving from
* one as part of {@link Message}. If used to create an Item to publish
* (via {@link LeafNode#publish(Item)}, the server may return an
* error for an invalid packet.
*
* @param itemId The id of the item.
* @param nodeId The id of the node which the item was published to.
*/
public Item(String itemId, String nodeId) {
this(ItemNamespace.pubsub, itemId, nodeId);
}
/**
* Create an Item with an id and a node id.
*
* Note: This is not valid for publishing an item to a node, only receiving from
* one as part of {@link Message}. If used to create an Item to publish
* (via {@link LeafNode#publish(Item)}, the server may return an
* error for an invalid packet.
*
* @param itemNamespace the namespace of the item.
* @param itemId The id of the item.
* @param nodeId The id of the node which the item was published to.
*/
public Item(ItemNamespace itemNamespace, String itemId, String nodeId) {
super(itemNamespace.type, nodeId);
this.itemId = itemId;
}
/**
* Get the item id. Unique to the node it is associated with.
*
* @return The id
*/
public String getId() {
return itemId;
}
@Override
protected void addXml(XmlStringBuilder xml) {
xml.optAttribute("id", getId());
xml.closeEmptyElement();
}
@Override
public String toString() {
return getClass().getName() + " | Content [" + toXML() + "]";
}
}