A "service" is a mechanism by which one plugin can work with other
plugins and avoid a bidirectional build-dependency. For example, the XML
plugin "depends" on Sidekick, but in fact, it is SideKick which creates
and operates on an object (a SideKickParser
, in fact)
defined in the XML plugin. In a way, the dependency is
bidirectional.
Similarly, the SshConsole plugin defines but does not instantiate
a Shell
object. It is the Console plugin which
creates a specific shell for each available service. SideKick and
Console use the ServiceManager
to search for services
offered by other plugins.
Here is an example of a service from the XML plugin, which extends Sidekick:
<!DOCTYPE SERVICES SYSTEM "services.dtd"> <SERVICES> <SERVICE CLASS="sidekick.SideKickParser" NAME="html"> new sidekick.html.HtmlParser(); </SERVICE> [...] </SERVICES>
The value of the CLASS=
should be a
base-class or interface of the object that is returned by
executing the beanshell factory method enclosed in the
<SERVICE>
tag.
In the case above, the returned object
tells Sidekick how it can parse files of a specific type (HTML).
The API docs for SideKickParser
should indicate precisely which methods must be implemented in a plugin
which offers this service.
For more information about services, refer to the ServiceManager
class API documentation. There, you can find out what the tags and
attributes mean, as well as how to register and use services.
You can also inspect the services.xml
file of jEdit
core to see what services are offered by jEdit itself.