Instantiating objects

Instantiation is the name given to the process of creating an object. This is done with the CREATE statement using the following grammar

OBJECT objname = CREATE strexpr1, strexpr2

Where objname is an object symbol defined in an earlier DIM OBJECT or LOCAL DIM OBJECT statement. The first argument strexpr1 defines the type of object. Currently ServerCOM, ClientCOM, Corba and SOAP are supported.

For COM objects the alpha expression strexpr2 on the right must be either a ProgId or a string ClassId defining the object in the appropriate registry. For example

OBJECT Doc = CREATE "ClientCOM","Word.Basic"
OBJECT rsTable = CREATE "ServerCOM", "ADODB.Recordset"
OBJECT rsTable = CREATE "ServerCOM","{00000535-0000-0010-8000-00AA006D2EA4}"

For Corba objects the alpha expressionstrexpr2 on the right must be either the object name in the naming service, or an Interoperable Object Reference (IOR). KCML must know how to find the naming service with which the object is registered. There are two ways of specifying the location of the naming service, either using the command line switch '-q' to KCML, or specifying additional arguments to CREATE. The exact syntax of the parameters depends on the ORB KCML is using.

Note that you can currently only connect to one ORB, so if you have already called CREATE before, or used the -q option, the additional arguments to CREATE are ignored

An example using MICO would be:

OBJECT Add = CREATE "Corba","Add", "-ORBNamingAddr", "inet:evb:9876" 

Or KCML could be started with "kcml -q -ORBNamingAddr inet:evb:9876", and the object created using only the name:

OBJECT Add = CREATE "Corba","Add"
OBJECT Add = CREATE "Corba","kerridge/my_context/Add/Object/"

The two object names above are equivalent, as KCML assumes a context name of "kerridge", with a type of "my_context" unless both the name and type are given, so if the object name is "Add", with a type of "Object", the name should be "Add/Object/".