This mod offers components that run LUA code and interface with each other through a global environment. It makes complex automated railway systems possible.
### atlatc
The mod is sometimes abbreviated as 'atlatc'. This stands for AdvTrainsLuaATC. This short name has been chosen for user convenience, since the name of this mod ('advtrains_luaautomation') is very long.
### Privilege
To perform any operations using this mod (except executing operation panels), players need the "atlatc" privilege.
This privilege should never be granted to anyone except trusted administrators. Even though the LUA environment is sandboxed, it is still possible to DoS the server by coding infinite loops or requesting expotentially growing interrupts.
### Active and passive
Active components are these who have LUA code running in them. They are triggered on specific events. Passive components are dumb, they only have a state and can be set to another state, they can't perform actions themselves.
### Environments
Each active component is assigned to an environment. This is where all data are held. Components in different environments can't inferface with each other.
This system allows multiple independent automation systems to run simultaneously without polluting each other's environment.
/env_create <env_name>
Create environment with the given name. To be able to do anything, you first need to create an environment. Choose the name wisely, you can't change it afterwards.
/env_setup <env_name>
Invoke the form to edit the environment's initialization code. For more information, see the section on active components. You can also delete an environment from here.
### Active components
The code of every active component is run on specific events which are explained soon. When run, every variable written that is not local and is no function or userdata is saved over code re-runs and over server restarts. Additionally, the following global variables are defined:
# event
The variable 'event' contains a table with information on the current event. How this table can look is explained below.
# S
The variable 'S' contains a table which is shared between all components of the environment. Its contents are persistent over server restarts. May not contain functions, every other value is allowed.
Example:
Component 1: S.stuff="foo"
Component 2: print(S.stuff)
-> foo
# F
The variable 'F' also contains a table which is shared between all components of the environment. Its contents are discarded on server shutdown or when the init code gets re-run. Every data type is allowed, even functions.
The purpose of this table is not to save data, but to provide static value and function definitions. The table should be populated by the init code.
# Standard Lua functions
The following standard Lua libraries are available:
string, math, table, os
The following standard Lua functions are available:
Cause LuaAutomation to trigger an 'int' event on this component after the given time in seconds with the specified 'message' field. 'message' can be of any Lua data type.
Not available in init code!
interrupt_pos(pos, message)
Immediately trigger an 'ext_int' event on the active component at position pos. 'message' is like in interrupt().
USE WITH CARE, or better don't use! Incorrect use can result in expotential growth of interrupts.
## Components and events
The event table is a table of the following format:
{
type = "<type>",
<type> = true,
... additional content ...
}
You can check for the event type by either using
if event.type == "wanted" then ...do stuff... end
or
if event.wanted then ...do stuff... end
(if 'wanted' is the event type to check for)
# Init code
The initialization code is not a component as such, but rather a part of the whole environment. It can (and should) be used to make definitions that other components can refer to.
Examples:
A function to define behavior for trains in subway stations:
function F.station()
if event.train then atc_send("B0WOL") end
if event.int and event.message="depart" then atc_send("OCD1SM") end
The init code is run whenever the F table needs to be refilled with data. This is the case on server startup and whenever the init code is changed and you choose to run it.
Functions are run in the environment of the currently active node, regardless of where they were defined. So, the 'event' table always reflects the state of the calling node.
The 'event' table of the init code is always {type="init", init=true}.
# ATC rails
The Lua-controlled ATC rails are the only components that can actually interface with trains. The following event types are generated:
{type="train", train=true, id="<train_id>"}
This event is fired when a train enters the rail. The field 'id' is the unique train ID, which is a long string (generated by concatenating os.time() and os.clock() at creation time). The Itrainmap mod displays the last 4 digits of this ID.
{type="int", int=true, message=<message>}
Fired when an interrupt set by the 'interrupt' function runs out. 'message' is the message passed to the interrupt function.
{type="ext_int", ext_int=true, message=<message>}
Fired when another node called 'interrupt_pos' on this position. 'message' is the message passed to the interrupt_pos function.
In addition to the default environment functions, the following functions are available:
