This page is loosely based on a great manual written by Patrick Talbot (as found on the Servoy forum), and is done so with the author's approval.

Client plugins are java classes contained in jar files stored under "/ServoyInstallDir/application_server/plugins/" folder, and by which you can add new features to Servoy Developer.

Plugins can be developed in any Java development environment, like Eclipse for example.

Preliminary settings

Example This is an example of a Java project called WhoisPlugin, and the Servoy libraries added to it.

Implementing the plugin

Create a new package under the Java project

A package is a neat way in Java to organize libraries coming from arbitrary sources and make them work together without problems of "Name collision".

You can name the package whatever you want, but, by convention, the package hierarchy should reflect your domain name (if you have any) in reverse (from domain to sub-domains). This will avoid name collision with any other libraries, and will spare you from having to type the "fully qualified name" in your code; Eclipse will automatically do that for you.

Example

This is an example of naming a package: com.servoy.plugins.whois  - where 'com.servoy' is a prefix which follows the rule listed above, and 'whois' is the plugin name.

Implement the plugin interface

In order to implement a client plugin, you need to create a class that implements one or more of the three interfaces: IServerPlugin, ISmartClientPlugin, and IClientPlugin.

Before starting coding, do study these interfaces on api docs.

Example

This example shows the implementation of a component which will query a whois server and retrieve whois information about a domain.

public class WhoisPlugin implements IClientPlugin {

    public static final String PLUGIN_NAME = "whois";
    private WhoisPluginProvider provider;
    
    @Override
    public Properties getProperties() {
        Properties props = new Properties();
        props.put(DISPLAY_NAME, getName());
        return props;
    }

    @Override
    public void load() throws PluginException {
        // ignore
    }

    @Override
    public void unload() throws PluginException {
        provider = null;
    }

    @Override
    public void propertyChange(PropertyChangeEvent arg0) {
        // ignore
    }

    @Override
    public IScriptable getScriptObject() {
        if (provider == null) {
            provider = new WhoisPluginProvider();
        } 
        return provider;
    }

    @Override
    public Icon getImage() {
        URL iconUrl = getClass().getResource("images/whois.png"); //the image is added under a package 'com.servoy.plugins.whois.images' added to the WhoisPlugin project.
        if (iconUrl != null) {
            return new ImageIcon(iconUrl);
        } else {
            return null;
        }
    }

    @Override
    public String getName() {
        return PLUGIN_NAME;
    }

    @Override
    public void initialize(IClientPluginAccess arg0) throws PluginException {
        // ignore
    }
}

Implement the script object

The method getStriptObject inherited by IClientPlugin from IScriptableProvider interface, returns the object that will provide the plugin with scripting properties and methods. So, by convention, it is called a Provider.

A provider implements interfaces IScriptable and IReturnedTypesProvider. Do study them on api docs.

Create a class which implements the two interfaces. This class will provide methods representing the plugin behavior.

Code the plugin main behavior

In order to specify which methods are what, you need to use the JavaDoc annotations system which identifies getter/setter methods for plugin properties, as well as function methods for the plugin functions. The JavaDoc annotation system is also used for documenting the plugin.

For a proper understanding of how to use JavaDoc and how to build the documentation of your plugin, see Documenting your plugin Api.

Example

This example shows the implementation of the WhoisPluginProvider - the scriptable object which provides the behavior for the "whois" plugin.

The plugin will expose an overloaded guery method, as well as three other properties: port, server, and timeout.

The main query method contains JavaDoc which provides a description of the function and a sample. The other overloaded methods will display the same description and sample, having them copied via @clonedesc and @sampleas annotations from the main method.

@ServoyDocumented(publicName = WhoisPlugin.PLUGIN_NAME, scriptingName = "plugins." + WhoisPlugin.PLUGIN_NAME)
public class WhoisPluginProvider implements IScriptable, IReturnedTypesProvider {

    @Override
    public Class<?>[] getAllReturnedTypes() {
        return null;
    }
    
    private String server = "whois.networksolutions.com";
    private int port = 43;
    private int timeout = 30 * 1000; // unit is milliseconds
    
    @JSGetter
    public String getServer() {
        return server;
    }

    @JSSetter
    public void setServer(String server) {
        this.server = server;
    }

    @JSGetter
    public int getPort() {
        return port;
    }

    @JSSetter
    public void setPort(int port) {
        this.port = port;
    }

    @JSGetter
    public int getTimeout() {
        return timeout;
    }

    @JSSetter
    public void setTimeout(int timeout) {
        this.timeout = timeout;
    }

    /**
     * @clonedesc query(String, String, int, int)
     * @sampleas query(String, String, int, int)
     * @param domainName
     */
    @JSFunction
    public String query(String domainName) {
        return query(domainName, this.server, this.port, this.timeout);
    }
    
    /**
     * @clonedesc query(String, String, int, int)
     * @sampleas query(String, String, int, int)
     * @param domainName
     * @param server
     */
    @JSFunction
    public String query(String domainName, String server) {
        return query(domainName, server, this.port, this.timeout);
    }
    
    /**
     * @clonedesc query(String, String, int, int)
     * @sampleas query(String, String, int, int)
     * @param domaninName
     * @param server
     * @param port
     */
    @JSFunction
    public String query(String domainName, String server, int port) {
        return query(domainName, server, port, this.timeout);
    }
    
    /**
     * Calls a whois server to retrieve information about the domain name you provide
     * 
     * @sample
     * // you call a whois server by providing a domain name and get info in return
     * var result = plugins.whois.query('servoy.com');
     * // alternatively you can provide an alternate server (default is networksolutions.com)
     * var result = plugins.whois.query('servoy.com', 'whois.internic.net');
     * // you can also provide a port, if not standard (43 by deafault)
     * var result = plugins.whois.query('servoy.com', 'whois.internic.net', 43);
     * // and you can also provide a timeout length (unit is milliseconds, default is 30 seconds)
     * var result = plugins.whois.query('servoy.com', 'whois.internic.net', 43, 50000);
     * 
     * @param domainName
     * @param server
     * @param port
     * @param timeout
     * @return
     */
    @JSFunction
    public String query(String domainName, String server, int port, int timeout) {
        try {
            // create the socket
            Socket socket = new Socket(server, port);
            socket.setSoTimeout(timeout);
            // create a reader to get the response from the server
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            // create an output stream to send our query to the server
            DataOutputStream out = new DataOutputStream(socket.getOutputStream());
            // call the service with the domainName supplied
            // and terminate with carriage return)
            out.writeBytes(domainName + " \r\n");
            // read the response from the server
            String str1 = null;
            StringBuffer buffer = new StringBuffer();
            while ((str1 = in.readLine()) != null) {
                buffer.append(str1);
                buffer.append("\r\n");
            }
            // close our stream and reader
            out.close();
            in.close();
            // close the socket
            socket.close();
            // return the result as String
            return buffer.toString();
        } catch (IOException ioEx) {
            return ioEx.getLocalizedMessage();
        } catch (Exception ex) {
            return ex.getLocalizedMessage();
        }
    }
}

Make sure you have selected the correct target against which your project is compiled. It needs to be consistent with the Java version your Servoy install is built against. For this, do check Project > Properties > Java Compiler Node > JDK Compliance Panel.

Entry Points

Since the class which implements the IServerPlugin, ISmartClientPlugin or IClientPlugin is one file among many inside your jar, you should indicate which file is the plugin entry point.

The plugin jar can use Java Service Provider to expose Servoy Plugin classes. There should be a file inside the plugin jar at the path: META-INF/services/com.servoy.j2db.plugins.IPlugin which contains a line for each class in the jar that  implements IPlugin). The plugin should also have a default constructor (with no parameters). If file com.servoy.j2db.plugins.IPlugin is missing or contains invalid entries Servoy will automatically scan the jar for all classes that implement interface IPlugin. An example of file content (for whois plugin) is:

com.servoy.plugins.whois.WhoisPlugin

Package the plugin

Testing the plugin

When opening the Servoy Developer, you should see the plugin under Plugins node in Solution Explorer.

Example #1 This example shows how the whois plugin is displayed in the Solution Explorer. Notice the overloaded function query and the three properties.

Example #2 This example shows a small sample solution WhoisTest which tests the whois plugin.

We have a simple test form with two fields based on two form variables domainName and result, and a button Query whois whose action will call the query function.

The Form Editor

The Script Editor

var domainName = "";
var result = "";

function onQueryWhois()
{
	if (domainName != null && domainName.length > 0) {
		result = plugins.whois.query(domainName, "whois.internic.net");
	}
}

Running Smart Client