IRC Hacks [Electronic resources] نسخه متنی

Hack 47 Write a Plug-in for PPF

Now that you know how to use the PircBot
Plug-in Framework and configure its various plug-ins, let your
creative juices flow by making your own plug-in.

PPF (PircBot Plug-in
Framework) is an open source (http://opensource.org) plug-in framework
built on top of the PircBot IRC API. It provides some basic
functionality, such as connecting to IRC, joining channels, and some
auth levels for access control. The PPF core itself
doesn't really do very much at all, as the
functionality comes from each of the plug-ins you use. Full details
about the project, latest releases, plug-ins, documentation, and
source code (via CVS) can be found at http://www.sourceforge.net/projects/ppf.

The plug-ins can be built quite easily by extending an abstract class
called PPFPlugin. By inheriting the functionality of this
class, a plug-in can include features such as XML configuration, and
it can store persistent data, be internationalizable, and also
provide dynamic online help.

This hack will show you how to create a simple plug-in and
demonstrate some of the features that make it easy to do frequently
performed tasks.

7.5.1 The Code

The simple plug-in will be called Simple, so create a new directory
called Simple under the
plugins directory. Then create the directory
path for the source code under that
(src/net/sourceforge/ppf/plugin/simpleplugin).
You should end up with something like Figure 7-4.

Figure 7-4. The directory structure for the Simple plug-in

Now create a file called SimplePlugin.java in
the simpleplugin directory:

package net.sourceforge.ppf.plugin.simpleplugin;
import net.sourceforge.ppf.PPF;
import net.sourceforge.ppf.PPFPlugin;
import net.sourceforge.ppf.util.PPFHelp;
public class SimplePlugin extends PPFPlugin {
static final String PLUGIN_VERSION = "1.0";
// The commands the plug-in will respond to.
static final String COMMAND_TIME = "!time";
static final String COMMAND_HELLO = "!hello";
public SimplePlugin( ) {
// Set the plug-in version information.
setVersion(PLUGIN_VERSION);
// Set the help responses for this plug-in.
setHelp(COMMAND_TIME, new PPFHelp(COMMAND_TIME, 
"Show the time of the server that the bot is running on",
PPF.AUTH_NONE));
setHelp(COMMAND_HELLO, new PPFHelp(COMMAND_HELLO,
"The bot says hello back to you", PPF.AUTH_NONE));
}
// Respond to channel messages.
public void onMessage(String channel, String sender, String login,
String hostname, String message) {
if(message.equalsIgnoreCase(COMMAND_TIME)) {
String time = new java.util.Date( ).toString( );
getBot( ).sendMessage(channel, sender +
": The time where I am is currently: "+ time);
} else if(message.equalsIgnoreCase(COMMAND_HELLO)) {
getBot( ).sendMessage(channel, "Hi there " + sender + "!");
}
}
}

7.5.2 Running the Hack

PPF uses ANT (http://ant.apache.org) as its build system.
The main build file has the necessary targets ready to call, so you
just need to make a simple build file for the plug-in that sets the
name and location of the plug-in and calls the main build file.

Make a file called build.xml in the new plug-in
directory. An easy way of doing this is to copy an existing one from
another plug-in and change the contents so it looks like this:

<?xml version="1.0"?>
<project basedir="." default="deploy">
<property name = "plugin.project" value = "Simple"/>
<property name = "plugin.name"    value = "Simple"/>
<path id="plugin.classpath">
<fileset dir=".">
<include name="*.jar"/>
</fileset>
</path>
<!-- Call the PPF build script to perform the build. 
You can set the plugin-specific details here and keep 
the PPF classpath in one place -->
<target name="compile">
<ant antfile="../../build.xml" target="compile.plugin" inheritRefs="true"/>
</target>
<target name="deploy" depends="compile">
<jar jarfile="./${plugin.name}.jar" basedir="bin"/>
</target>
</project>

Run the deploy target from the project build file
and the source code will be compiled. The compiled bytecode will be
placed into a JAR file in the plug-in directory named
Simple.jar.

PPF now needs to be configured to load this plug-in. In
PPFConfig.xml, you need to add:

<plugin load="yes">
<name>Simple</name>
<classname>net.sourceforge.ppf.plugin.simpleplugin.SimplePlugin</classname>
</plugin>

If PPF is not yet running, just start it and the Simple plug-in will
be loaded.

If PPF is already running, you can auth as admin
by entering:

/msg BotName auth adminPassword

The plug-in can then be loaded dynamically by entering:

/msg BotName loadplugin Simple

The plug-in is now ready to be used and will respond to
!time and !hello:

<DeadEd> !time
<PPF> DeadEd: The time where I am is currently: Thu Mar 18 13:48:32 EET 2004
<DeadEd> !hello
<PPF> Hi there DeadEd!

7.5.3 Creating Advanced Plug-ins

This is an example of some of the things that
can be achieved with the plug-in framework. All
onXxx methods available from the PircBot
API are passed to the plugin class. Methods are
also available to assist in reading in XML configuration files,
making some information persistent, viewing that information,
internationalization, and dynamic help.

Alex North