This method is called by the implementation of the method
on a newly constructed extension, passing it its relevant configuration
information. Most executable extensions only make use of the first
two call arguments.
Regular executable extensions specify their Java implementation
class name as an attribute of the configuration element for the
extension. For example
In the above example, this method would be called with a reference
<action> element (first argument), and
"run" as the name of the attribute that defined
this executable extension (second argument).
The last parameter is for the specific use of extension adapters
and is typically not used by regular executable extensions.
There are two supported ways of associating additional
adapter-specific data with the configuration in a way that
is transparent to the extension point implementor:
(1) by specifying adapter data as part of the implementation
class attribute value. The Java class name can be followed
by a ":" separator, followed by any adapter data in string
form. For example, if the extension point specifies an attribute
"run" to contain the name of the extension implementation,
an adapter can be configured as
<action run="com.example.ExternalAdapter:./cmds/util.exe -opt 3"/>
(2) by converting the attribute used to specify the executable
extension to a child element of the original configuration element,
and specifying the adapter data in the form of xml markup.
Using this form, the example above would become
<parameter name="exec" value="./cmds/util.exe"/>
<parameter name="opt" value="3"/>
Form (2) will typically only be
used for extension points that anticipate the majority of
extensions configured into it will in fact be in the form
In either case, the specified adapter class is instantiated using its
0-argument public constructor. The adapter data is passed as the
last argument of this method. The data argument is defined as Object.
It can have the following values:
null, if no adapter data was supplied
- in case (1), the initialization data
string is passed as a
- in case (2), the initialization data is passed
Hashtable containing the actual
parameter names and values (both
config - the configuration element used to trigger this execution.
It can be queried by the executable extension for specific
propertyName - the name of an attribute of the configuration element
used on the
createExecutableExtension(String) call. This
argument can be used in the cases where a single configuration element
is used to define multiple executable extensions.
data - adapter data in the form of a