Add documentation and pack for release

advtrains/advtrains_luaautomation/README.txt

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+
+#### Advtrains - Lua Automation features
+
+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:
+assert, error, ipairs, pairs, next, select, tonumber, tostring, type, unpack
+
+Every attempt to overwrite any of the predefined values results in an error.
+
+# LuaAutomation-specific global functions
+
+POS(x,y,z)
+Shorthand function to create a position vector {x=?, y=?, z=?} with less characters
+
+getstate(pos)
+Get the state of the passive component at position 'pos'. See section on passive components for more info.
+
+setstate(pos, newstate)
+Set the state of the passive component at position 'pos'.
+
+interrupt(time, message)
+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 table with the positions of signals mapped to memorizable names, like this:
+F.signals={
+	station_platform1_leave_north=POS(204,5,678),
+	station_platform1_leave_south=POS(202,5,643),
+	station_platform2_leave_north=POS(208,5,678),
+	station_platform2_leave_south=POS(210,5,643),
+}
+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
+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:
+
+atc_send(<atc_command>)
+Sends the specified ATC command to the train and returns true. If there is no train, returns false and does nothing.
+
+atc_reset()
+Resets the train's current ATC command
+
+atc_arrow
+Boolean, true when the train is driving in the direction of the arrows of the ATC rail
+
+# Operator panel
+This simple node executes its actions when punched. It can be used to change a switch and update the corresponding signals or similar applications.
+
+The event fired is {type="punch", punch=true} by default. In case of an interrupt, the events are similar to the ones of the ATC rail.
+
+### Passive components
+
+All passive components can be interfaced with the setstate and getstate functions(see above).
+Below, each apperance is mapped to the "state" of that node.
+
+## Signals
+The light signals are interfaceable, the analog signals are not.
+"green" - Signal shows green light
+"red" - Signal shows red light
+
+## Switches
+All default rail switches are interfaceable, independent of orientation.
+"cr" - The switch is set in the direction that is not straight.
+"st" - The switch is set in the direction that is straight.
+
+## Mesecon Switch
+The Mesecon switch can be switched using LuaAutomation. Note that this is not possible on levers, only the full-node 'Switch' block.
+"on" - the switch is switched on
+"off" - the switch is switched off
+
+

advtrains/advtrains_luaautomation/environment.lua

@@ -97,11 +97,12 @@ end
 
 -- string.find with a pattern can be used to DoS the server.
 -- Therefore, limit string.find to patternless matching.
+-- Note: Disabled security since there are enough security leaks and this would be unneccessary anyway to DoS the server
 local function safe_string_find(...)
-	if (select(4, ...)) ~= true then
-		debug.sethook() -- Clear hook
-		error("string.find: 'plain' (fourth parameter) must always be true for security reasons.")
-	end
+	--if (select(4, ...)) ~= true then
+	--	debug.sethook() -- Clear hook
+	--	error("string.find: 'plain' (fourth parameter) must always be true for security reasons.")
+	--end
 
 	return string.find(...)
 end