Smack/documentation/extensions/xhtml.html

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<title>XHTML Support</title>
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<div class="header">XHTML Messages</div><p>
Provides the ability to send and receive formatted messages using XHTML.
<p>Follow these links to learn how to compose, send, receive and discover support for
XHTML messages:</p>
<ul>
<li><a href="#xhtmlcompose">Compose an XHTML Message</a></li>
<li><a href="#xhtmlsend">Send an XHTML Message</a></li>
<li><a href="#xhtmlreceive">Receive an XHTML Message</a></li>
<li><a href="#xhtmldiscover">Discover support for XHTML Messages</a></li>
</ul>
<b>XEP related:</b> <a href="http://www.xmpp.org/extensions/xep-0071.html">XEP-71</a>
<hr>
<div class="subheader"><a name="xhtmlcompose">Compose an XHTML Message</a></div><p>
<b>Description</b><p>
The first step in order to send an XHTML message is to compose it. Smack provides a special
class that helps to build valid XHTML messages hiding any low level complexity.
For special situations, advanced users may decide not to use the helper class and generate
the XHTML by themselves. Even for these situations Smack provides a well defined entry point
in order to add the generated XHTML content to a given message.</p>
<p>
Note: not all clients are able to view XHTML formatted messages. Therefore,
it's recommended that you include a normal body in that message that is either an
unformatted version of the text or a note that XHTML support is required
to view the message contents.</p>
<b>Usage</b><p>
Create an instance of <i><b>XHTMLText</b></i> specifying the style and language of the body.
You can add several XHTML bodies to the message but each body should be for a different language.
Once you have an XHTMLText you can start to append tags and text to it. In order to append tags there
are several messages that you can use. For each XHTML defined tag there is a message that you can send.
In order to add text you can send the message <b>#append(String textToAppend)</b>.</p>
<p>After you have configured the XHTML text, the last step you have to do is to add the XHTML text
to the message you want to send. If you decided to create the XHTML text by yourself, you will have to
follow this last step too. In order to add the XHTML text to the message send the message
<b>#addBody(Message message, String body)</b> to the <i><b>XHTMLManager</b></i> class where <i>message</i>
is the message that will receive the XHTML body and <i>body</i> is the string to add as an XHTML body to
the message.</b></p>
<b>Example</b><p>
In this example we can see how to compose the following XHTML message: <br>
<font color="#0000FF">&lt;body&gt;&lt;p style='font-size:large'&gt;Hey John, this is my new &lt;span
style='color:green'&gt;green&lt;/span&gt;&lt;em&gt;!!!!&lt;/em&gt;&lt;/p&gt;&lt;/body&gt;</font>
<blockquote>
<pre> <font color="#3f7f5f">// Create a message to send</font>
Message msg = chat.createMessage();
msg.setSubject(<font color="#0000FF">"Any subject you want"</font>);
msg.setBody(<font color="#0000FF">"Hey John, this is my new green!!!!"</font>);
<font color="#3f7f5f">// Create an XHTMLText to send with the message</font>
XHTMLText xhtmlText = new XHTMLText(null, null);
xhtmlText.appendOpenParagraphTag(<font color="#0000FF">"font-size:large"</font>);
xhtmlText.append(<font color="#0000FF">"Hey John, this is my new "</font>);
xhtmlText.appendOpenSpanTag(<font color="#0000FF">"color:green"</font>);
xhtmlText.append(<font color="#0000FF">"green"</font>);
xhtmlText.appendCloseSpanTag();
xhtmlText.appendOpenEmTag();
xhtmlText.append(<font color="#0000FF">"!!!!"</font>);
xhtmlText.appendCloseEmTag();
xhtmlText.appendCloseParagraphTag();
<font color="#3f7f5f">// Add the XHTML text to the message</font>
XHTMLManager.addBody(msg, xhtmlText.toString());
</pre>
</blockquote>
<hr>
<div class="subheader"><a name="xhtmlsend">Send an XHTML Message</a></div><p>
<b>Description</b><p>
After you have composed an XHTML message you will want to send it. Once you have added
the XHTML content to the message you want to send you are almost done. The last step is to send
the message as you do with any other message.</p>
<b>Usage</b><p>
An XHTML message is like any regular message, therefore to send the message you can follow
the usual steps you do in order to send a message. For example, to send a message as part
of a chat just use the message <b>#send(Message)</b> of <i><b>Chat</b></i> or you can use
the message <b>#send(Packet)</b> of <i><b>XMPPConnection</b></i>.</p>
<b>Example</b><p>
In this example we can see how to send a message with XHTML content as part of a chat.
<blockquote>
<pre> <font color="#3f7f5f">// Create a message to send</font>
Message msg = chat.createMessage();
<font color="#3f7f5f">// Obtain the XHTML text to send from somewhere</font>
String xhtmlBody = getXHTMLTextToSend();
<font color="#3f7f5f">// Add the XHTML text to the message</font>
XHTMLManager.addBody(msg, xhtmlBody);
<font color="#3f7f5f">// Send the message that contains the XHTML</font>
chat.sendMessage(msg);
</pre>
</blockquote>
<hr>
<div class="subheader"><a name="xhtmlreceive">Receive an XHTML Message</a></div><p>
<b>Description</b><p>
It is also possible to obtain the XHTML content from a received message. Remember
that the specification defines that a message may contain several XHTML bodies
where each body should be for a different language.</p>
<b>Usage</b><p>
To get the XHTML bodies of a given message just send the message <b>#getBodies(Message)</b>
to the class <i><b>XHTMLManager</b></i>. The answer of this message will be an
<i><b>Iterator</b></i> with the different XHTML bodies of the message or null if none.</p>
<b>Example</b><p>
In this example we can see how to create a PacketListener that obtains the XHTML bodies of any received message.
<blockquote>
<pre> <font color="#3f7f5f">// Create a listener for the chat and display any XHTML content</font>
PacketListener packetListener = new PacketListener() {
public void processPacket(Packet packet) {
Message message = (Message) packet;
<font color="#3f7f5f">// Obtain the XHTML bodies of the message</font>
Iterator it = XHTMLManager.getBodies(message);
if (it != null) {
<font color="#3f7f5f">// Display the bodies on the console</font>
while (it.hasNext()) {
String body = (String) it.next();
System.out.println(body);
}
}
};
chat.addMessageListener(packetListener);
</pre>
</blockquote>
<hr>
<div class="subheader"><a name="xhtmldiscover">Discover support for XHTML Messages</a></div><p>
<b>Description</b><p>
Before you start to send XHTML messages to a user you should discover if the user supports XHTML messages.
There are two ways to achieve the discovery, explicitly and implicitly. Explicit is when you first try
to discover if the user supports XHTML before sending any XHTML message. Implicit is when you send
XHTML messages without first discovering if the conversation partner's client supports XHTML and depenging on
the answer (normal message or XHTML message) you find out if the user supports XHTML messages or not. This
section explains how to explicitly discover for XHTML support.</p>
<b>Usage</b><p>
In order to discover if a remote user supports XHTML messages send <b>#isServiceEnabled(XMPPConnection
connection, String userID)</b> to the class <i><b>XHTMLManager</b></i> where connection is the connection
to use to perform the service discovery and userID is the user to check (A fully qualified xmpp ID,
e.g. jdoe@example.com). This message will return true if the specified user handles XHTML messages.</p>
<b>Example</b><p>
In this example we can see how to discover if a remote user supports XHTML Messages.
<blockquote>
<pre> Message msg = chat.createMessage();
<font color="#3f7f5f">// Include a normal body in the message</font>
msg.setBody(getTextToSend());
<font color="#3f7f5f">// Check if the other user supports XHTML messages</font>
if (XHTMLManager.isServiceEnabled(connection, chat.getParticipant())) {
<font color="#3f7f5f">// Obtain the XHTML text to send from somewhere</font>
String xhtmlBody = getXHTMLTextToSend();
<font color="#3f7f5f">// Include an XHTML body in the message</font>
XHTMLManager.addBody(msg, xhtmlBody);
}
<font color="#3f7f5f">// Send the message</font>
chat.sendMessage(msg);
</pre>
</blockquote>
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