Common Script Interface

Many WSF components use the WSF ‘common script interface’. An WSF component that uses the interface will accept:

  • Definitions of script variables: script_variables … end_script_variables

  • Definitions of scripts: script … end_script

  • Scripting system control commands (e.g., script_call_trace)

  • Common Scripts (defined below)

The WSF components that currently implement common script interface include:

  • The simulation.

  • The platform.

  • Some processors such as WSF_SCRIPT_PROCESSOR, and many others.

  • Some other platform parts, such as sensors.

Example:

processor my-script-proc WSF_SCRIPT_PROCESSOR
   update_interval 10 sec
   on_update
      writeln("T=", TIME_NOW, " ", PLATFORM.Name(), " is updating");
   end_on_update
end_processor

Predefined Variables

All components that use the Common Script Interface will have the following predefined variables as is appropriate for the component:

double TIME_NOW

The current simulation time in seconds. This is available to all scripts.

WsfPlatform PLATFORM

A reference to the platform. This is valid only within the platforms, sensors, and processors that implement the common script interface

Note

This is not available in simulation-level scripts.

WsfProcessor PROCESSOR

A reference to the processor. This is valid only in processors that use the common script interface (e.g., WSF_SCRIPT_PROCESSOR).

Note

This variable is not available in simulation-level or platform-level scripts

WsfSensor SENSOR

A reference to the sensor. This is valid within AFSIM’s predefined sensors, as well as any other sensors that use the common script interface.

Note

This variable is not available in simulation-level or platform-level scripts

WsfRandom RANDOM

A reference to the random number generator used by the simulation.

Note

Use of this object will affect the simulation’s random draws and therefore repeatability of simulation outcomes.

Common Scripts

Every WSF component that uses the common script interface will accept the following common scripts:

execute at_time <time-value> [ absolute | relative ] …script body… end_execute
execute at_interval_of <time-value> …script body… end_execute

These commands allow you define a script that is to execute once at a specific time or repeatedly at a specified time interval.

To execute a script at a specific time:

execute at_time <time-value> [ absolute | relative ]
   Script Body
end_execute

If absolute is specified then the script will be executed at the specified simulation time.

If relative is specified then the script will be executed at the specified time relative to the creation time of the platform.

To execute a script repeatedly at a specified interval:

execute at_interval_of <time-value>
   Script Body
end_execute

Note

If defined in the context of a processor, these scripts will execute even if the system is turned off as the purpose of the script may be to turn the system on!

on_initialize …script_body… end_on_initialize

This command lets one define a script that is executed during phase 1 of platform initialization, if defined within the context of a platform, or during simulation initialization, if defined in the global script context.

During phase 1 initialization one may not assume anything about the state of the platform or any other platform component. If such a requirement is needed use the on_initialize2 script defined below.

on_initialize
   Script Body
end_on_initialize
on_initialize2 …script_body… end_on_initialize2

This command lets one define a script that is executed during phase 2 of platform initialization. Phase 2 initialization occurs when all platforms and their components (including those in the same platform context) have completed phase 1 initialization. Furthermore, phase 2 initialization at the platform context only occurs after phase 1 initialization at the global context.

Note

The on_initialize2 command is not available in the global (simulation-level) script context.

on_initialize2
   Script Body
end_on_initialize2
on_update …script_body… end_on_update

This command lets one define a script that is executed whenever the platform or processor is updated. When specified within the context of a processor, the “update_interval’ command defines the interval at which the simulation invokes the “Update’ method.

Note

Use this with great caution at the platform level as it can have severe performance impacts. The on_update command is not available in the global (simulation-level) script context.

on_update
   Script Body
end_on_update

Military Specific

An WSF component that uses the interface will accept:

Predefined Variables

WsfWeapon WEAPON

A reference to the weapon. This is valid only within weapons that use the common script interface (e.g., WSF_EXPLICIT_WEAPON).

Note

This variable is not available in simulation-level or platform-level scripts.