ISXDK:Adding a Top-Level Object

Summary

This tutorial is to help explain the basics of adding a Top-Level Object

Adding a Top Level Object

When our extension is loaded Inner Space calls the Initialize function inside of it. In our test extension we have ISXTest::Initialize call the function RegisterTopLevelObjects() to load all the TLOs into LavishScript. Inside RegisterTopLevelObjects() we use pISInterface->AddTopLevelObject(char *Name, fLSTopLevelObject Function) to load each TLO.

Example

void ISXTest::RegisterTopLevelObjects()
{
        pISInterface->AddTopLevelObject("ISXTest",TLO_ISXTest);
}

Removing a Top Level Object

Removing a command is basically just like adding a command. When an extension gets unloaded Inner Space calls the function Shutdown that is a required part of each extension. In our test extension we call the function UnRegisterTopLevelObjects() inside of Shutdown. The function to remove a TLO is pISInterface->RemoveTopLevelObject(char *Name).

Example

void ISXTest::UnRegisterTopLevelObjects()
{
       pISInterface->RemoveTopLevelObject("ISXTest");
}

Creating a Top Level Object function

A top level objects function is where you define the behavior of a TLO.Lets look at the example below and see what each part of the a TLO is.

• bool

This is the functions return type

• __cdecl

This is the calling convention for LavishScript TLO functions

• TLO_ISXTest

This is the name for our TLO function. We use TLO_ prefix for TLO functions as a standard convention, ISXTest is the name of the Top Level Object

• (int argc, char *argv[], LSTYPEVAR &Dest)

int argc is the number of arguments given

char *argv[] is all the arguments given

LSTYPEVAR &Dest is an object identifier structure. It uses a data portion and a type portion. Select a type to "return", and set the data to an appropriate value for that data type. For example, a string would use "Hello World" or an int would simply use an integer value. Be sure to validate the data (e.g. make sure you're not setting the data to NULL and calling it a string!).

• return true

returning true because it successfully set Dest.Ptr and Dest.Type

• printf("ISXTest Sample Command");

This is the main action our command function, its purpose is to display "ISXTest Sample Command" to the InnerSpace session console

• return 0;

This ends our function and returns 0 to anything looking for its return value

Example

bool __cdecl TLO_ISXTest(int argc, char *argv[], LSTYPEVAR &Dest)
{
       Dest.Ptr="Hello World";
       Dest.Type=pStringType;
       return true;
}

See Also

ISXDK