DML/modules/cfxSSBClient.lua

cfxSSBClient = {}
cfxSSBClient.version = "3.0.1"
cfxSSBClient.verbose = false 
cfxSSBClient.singleUse = false -- set to true to block crashed planes
-- NOTE: singleUse (true) requires SSB to disable immediate respawn after kick
cfxSSBClient.reUseAfter = -1 -- seconds for re-use delay
  -- only when singleUse is in effect. -1 means never 
  
cfxSSBClient.requiredLibs = {
	"dcsCommon", -- always
	"cfxGroups", -- for slot access
	"cfxZones", -- Zones, of course 
}

--[[--
Version History
  1.0.0 - initial version
  1.1.0 - detect airfield by action and location, not group name
  1.1.1 - performance tuning. only read player groups once 
        - and remove in-air-start groups from scan. this requires
        - ssb (server) be not modified	
  1.2.0 - API to close airfields: invoke openAirFieldNamed() 
          and closeAirfieldNamed() with name as string (exact match required)
		  to block an airfield for any player aircraft.
		  Works for FARPS as well 
		  API to associate a player group with any airfied's status (nil for unbind):
		  cfxSSBClient.bindGroupToAirfield(group, airfieldName)
		  API shortcut to unbind groups: cfxSSBClient.unbindGroup(group) 
		  verbose messages now identify better: "+++SSB:"
		  keepInAirGroups option 
  2.0.0 - include single-use ability: crashed airplanes are blocked from further use
        - single-use can be turned off 
		- getPlayerGroupForGroupNamed()
		- split setSlotAccess to single accessor 
		  and interator
		- reUseAfter option for single-use  
		- dcsCommon, cfxZones import
  2.0.1 - stricter verbosity: moved more comments to verbose only 
  2.0.2 - health check code (initial) 
		- added verbosity
  2.0.3 - getPlayerName nil-trap on cloned player planes guard 
          in onEvent
  2.1.0 - slotState
        - persistence 
  3.0.0 - closing an airfield will not kick players who are active 
		- much better verbosity
		- open?
		- close? 
		- also persists closed airfield list
  3.0.1 - ability to detect if an airfield doesn't exist (late activate)
		
		
	
WHAT IT IS
SSB Client is a small script that forms the client-side counterpart to
Ciribob's simple slot block. It will block slots for all client airframes
that are on an airfield that does not belong to the faction that currently
owns the airfield. 

REQUIRES CIRIBOB's SIMPLE SLOT BLOCK (SSB) TO RUN ON THE SERVER

If run without SSB, your planes will not be blocked.

In order to work, a plane that should be blocked when the airfield or 
FARP doesn't belong to the player's faction, the group's first unit
must be within 3000 meters of the airfield and on the ground. 
Previous versions of this script relied on group names. No longer.


WARNING:
If you modified ssb's flag values, this script will not work 

YOU DO NOT NEED TO ACTIVATE SBB, THIS SCRIPT DOES SO AUTOMAGICALLY


--]]--

-- below value for enabled MUST BE THE SAME AS THE VALUE OF THE SAME NAME 
-- IN SSB. DEFAULT IS ZERO, AND THIS WILL WORK

cfxSSBClient.enabledFlagValue = 0 -- DO NOT CHANGE, MUST MATCH SSB 
cfxSSBClient.disabledFlagValue = cfxSSBClient.enabledFlagValue + 100 -- DO NOT CHANGE
cfxSSBClient.allowNeutralFields = false -- set to FALSE if players can't spawn on neutral airfields 
cfxSSBClient.maxAirfieldRange = 3000 -- meters to airfield before group is no longer associated with airfield 
-- actions to home in on when a player plane is detected and a slot may 
-- be blocked. Currently, homing in on airfield, but not fly over 
cfxSSBClient.slotActions = {
	"From Runway",
	"From Parking Area",
	"From Parking Area Hot",
	"From Ground Area",
	"From Ground Area Hot",
}
cfxSSBClient.keepInAirGroups = false -- if false we only look at planes starting on the ground 
-- setting this to true only makes sense if you plan to bind in-air starts to airfields 

cfxSSBClient.playerGroups = {}
cfxSSBClient.closedAirfields = {} -- list that closes airfields for any aircrafts
cfxSSBClient.playerPlanes = {} -- names of units that a player is flying
cfxSSBClient.crashedGroups = {} -- names of groups to block after crash of their player-flown plane 
cfxSSBClient.slotState = {} -- keeps a record of which slot has which value. For persistence and debugging 
cfxSSBClient.occupiedUnits = {} -- by unit name if occupied to prevent kicking. clears after crash or leaving plane 
-- will not be persisted because on start all planes are empty 

-- dml zone interface for open/close interface
cfxSSBClient.clientZones = {}

function cfxSSBClient.addClientZone(theZone)
	table.insert(cfxSSBClient.clientZones, theZone)
end

function cfxSSBClient.getClientZoneByName(aName) 
	for idx, aZone in pairs(cfxSSBClient.clientZones) do 
		if aName == aZone.name then return aZone end 
	end
	if cfxSSBClient.verbose then 
		trigger.action.outText("+++ssbc: no client zone with name <" .. aName ..">", 30)
	end 

	return nil 
end

--
-- read client zones 
--
function cfxSSBClient.createClientZone(theZone)
	local thePoint = cfxZones.getPoint(theZone)
	local theAF = cfxSSBClient.getClosestAirbaseTo(thePoint)
	local afName = theAF:getName()
	if cfxSSBClient.verbose or theZone.verbose then 
		trigger.action.outText("+++ssbc: zone <" .. theZone.name .. "> linked to AF/FARP <" .. afName .. ">", 30)
	end
	theZone.afName = afName
	theZone.ssbTriggerMethod = cfxZones.getStringFromZoneProperty(theZone, "ssbTriggerMethod", "change")
	
	if cfxZones.hasProperty(theZone, "open?") then 
		theZone.ssbOpen = cfxZones.getStringFromZoneProperty(theZone, "open?", "none")
		theZone.lastSsbOpen = cfxZones.getFlagValue(theZone.ssbOpen, theZone)
	end
	
	if cfxZones.hasProperty(theZone, "close?") then 
		theZone.ssbClose = cfxZones.getStringFromZoneProperty(theZone, "close?", "none")
		theZone.lastSsbClose = cfxZones.getFlagValue(theZone.ssbClose, theZone)
	end
	
	theZone.ssbOpenOnStart = cfxZones.getBoolFromZoneProperty(theZone, "openOnStart", true)
	if not theZone.ssbOpenOnStart then 
		cfxSSBClient.closeAirfieldNamed(theZone.afName)
	end
end

--
-- Open / Close Airfield API 
--
function cfxSSBClient.closeAirfieldNamed(name)
	if not name then return end 
	cfxSSBClient.closedAirfields[name] = true 
	cfxSSBClient.setSlotAccessByAirfieldOwner()
	if cfxSSBClient.verbose then 
		trigger.action.outText("+++SSB: Airfield " .. name .. " now closed", 30) 
	end
end

function cfxSSBClient.openAirFieldNamed(name)
	cfxSSBClient.closedAirfields[name] = nil 
	cfxSSBClient.setSlotAccessByAirfieldOwner()
	if cfxSSBClient.verbose then 
		trigger.action.outText("+++SSB: Airfield " .. name .. " just opened", 30) 
	end
end

function cfxSSBClient.unbindGroup(groupName)
	cfxSSBClient.bindGroupToAirfield(groupName, nil)
end

function cfxSSBClient.bindGroupToAirfield(groupName, airfieldName)
	if not groupName then return end 
	local airfield = nil
	if airfieldName then airfield = Airbase.getByName(airfieldName) end 
	for idx, theGroup in pairs(cfxSSBClient.playerGroups) do
		if theGroup.name == groupName then 
			if cfxSSBClient.verbose then
				local newBind = "NIL"
				if airfield then newBind = airfieldName end 
				trigger.action.outText("+++SSB: Group " .. theGroup.name .. " changed binding to " .. newBind, 30) 
			end
			theGroup.airfield = airfield
			return
		end
	end
	if not airfieldName then airfieldName = "<NIL>" end 
	trigger.action.outText("+++SSB: Binding Group " .. groupName .. " to " .. airfieldName .. " failed.", 30) 
end


function cfxSSBClient.getClosestAirbaseTo(thePoint)
	local delta = math.huge
	local allYourBase = world.getAirbases() -- get em all
	local closestBase = nil 
	for idx, aBase in pairs(allYourBase) do
		-- iterate them all 
		local abPoint = aBase:getPoint()
		newDelta = dcsCommon.dist(thePoint, {x=abPoint.x, y = 0, z=abPoint.z})
		if newDelta < delta then 
			delta = newDelta
			closestBase = aBase
		end
	end
	return closestBase, delta 
end

function cfxSSBClient.setSlotAccessForGroup(theGroup)
	if not theGroup then return end 
	-- WARNING: theGroup is cfxGroup record  
	local theName = theGroup.name 
	
	-- we now check if any plane of that group is still 
	-- existing and in the air. if so, we skip this check
	-- to prevent players being kicked for losing their 
	-- originating airfield 
	
	-- we now iterate all playerUnits in theGroup.
	-- theGroup is cfxGroup 
	for idx, playerData in pairs (theGroup.playerUnits) do 
		local uName = playerData.name 
		if cfxSSBClient.occupiedUnits[uName] then 
			if cfxSSBClient.verbose then 
				trigger.action.outText("+++ssbc: unit <" .. uName .. "> of group <" .. theName .. "> is occupied, no airfield check", 30)
			end
			return 
		end
	end
	
	-- when we get here, no unit in the entire group is occupied 
	local theMatchingAirfield = theGroup.airfield 
	-- airfield was attached at startup to group 
	if cfxSSBClient.singleUse and cfxSSBClient.crashedGroups[theName] then 
	   -- we don't check, as we know it's blocked after crash 
	   -- and leave it as it is. Nothing to do at all now
		   
	elseif theMatchingAirfield ~= nil then 
		local blockState = cfxSSBClient.enabledFlagValue -- we default to ALLOW the block
		local comment = "available"
		-- we have found a plane that is tied to an airfield 
		-- so this group will receive a block/unblock
		-- we always set all block/unblock every time

		-- see if airfield currently exist (might be dead or late activate)
		if not Object.isExist(theMatchingAirfield) then
			-- airfield does not exits yet/any more 
			blockState = cfxSSBClient.disabledFlagValue
			comment = "!inactive airfield!"
		else 
			local airFieldSide = theMatchingAirfield:getCoalition()
			local groupCoalition = theGroup.coaNum
			
			-- see if airfield is closed 
			local afName = theMatchingAirfield:getName()
			if cfxSSBClient.closedAirfields[afName] then 
				-- airfield is closed. no take-offs 
				blockState = cfxSSBClient.disabledFlagValue
				comment = "!closed airfield!"
			end
				
			-- on top of that, check coalitions
			if groupCoalition ~= airFieldSide then 
				-- we have a problem. sides don't match 
				if airFieldSide == 3 
				or (cfxSSBClient.allowNeutralFields and airFieldSide == 0)
				then 
					-- all is well, airfield is contested or neutral and 
					-- we allow this plane to spawn here
				else 
					-- DISALLOWED!!!!
					blockState = cfxSSBClient.disabledFlagValue
					comment = "!!!BLOCKED!!!"
				end
			end 
		end 
		
		-- now set the ssb flag for this group so the server can see it
		if cfxSSBClient.verbose then 
			local lastState = trigger.misc.getUserFlag(theName)
			if lastState ~= blockState then 
				trigger.action.outText("+++ssbc: <" .. theName .. "> changes from <" .. lastState .. "> to <" .. blockState .. ">", 30)
				trigger.action.outText("+++SSB: group ".. theName .. ": " .. comment, 30)
			end
		end
		trigger.action.setUserFlag(theName, blockState)
		cfxSSBClient.slotState[theName] = blockState
		--if cfxSSBClient.verbose then 
		--end 
	else 
		if cfxSSBClient.verbose then 
			trigger.action.outText("+++SSB: group ".. theName .. " no bound airfield: available", 30)
		end
	end
end

function cfxSSBClient.setSlotAccessForUnit(theUnit) -- calls setSlotAccessForGroup
	if not theUnit then return end 
	local theGroup = theUnit:getGroup()
	if not theGroup then return end 
	local gName = theGroup:getName()
	if not gName then return end 
	local pGroup = cfxSSBClient.getPlayerGroupForGroupNamed(gName)
	if pGroup then   
		cfxSSBClient.setSlotAccessForGroup(pGroup) 
	end
end

function cfxSSBClient.getPlayerGroupForGroupNamed(aName)
	local pGroups = cfxSSBClient.playerGroups
	for idx, theGroup in pairs(pGroups) do
		if theGroup.name == aName then return theGroup end 
	end
	return nil 
end

function cfxSSBClient.setSlotAccessByAirfieldOwner()
	-- get all groups that have a player-controlled aircraft
	-- now uses cached, reduced set of player planes
	local pGroups = cfxSSBClient.playerGroups 
	for idx, theGroup in pairs(pGroups) do
		cfxSSBClient.setSlotAccessForGroup(theGroup)
	end
end

function cfxSSBClient.reOpenSlotForGroupNamed(args)
	-- this is merely the timer shell for opening the crashed slot
	gName = args[1]
	cfxSSBClient.openSlotForCrashedGroupNamed(gName)
end

function cfxSSBClient.openSlotForCrashedGroupNamed(gName)
	if not gName then return end
	local pGroup = cfxSSBClient.getPlayerGroupForGroupNamed(gName)
	if not pGroup then return end 
	cfxSSBClient.crashedGroups[gName] = nil -- set to nil to forget this happened 
	cfxSSBClient.setSlotAccessForGroup(pGroup) -- set by current occupation status 
	if cfxSSBClient.verbose then 
		trigger.action.outText("+++SSBC:SU: re-opened slot for group <" .. gName .. ">", 30)
	end 
end

function cfxSSBClient:onEvent(event) 
	if event.id == 21 then -- S_EVENT_PLAYER_LEAVE_UNIT
		local theUnit = event.initiator
		if not theUnit then
			if cfxSSBClient.verbose then
				trigger.action.outText("+++SSB: No unit left, abort", 30)
			end
			return 
		end 
		local curH = theUnit:getLife()
		local maxH = theUnit:getLife0()
		local uName = theUnit:getName()
		if cfxSSBClient.verbose then 
			trigger.action.outText("+++SSB: Player leaves unit <" .. uName .. ">", 30)
			trigger.action.outText("+++SSB: unit health check: " .. curH .. " of " .. maxH, 30)
		end
		
		cfxSSBClient.occupiedUnits[uName] = nil -- forget I was occupied
		cfxSSBClient.setSlotAccessForUnit(theUnit) -- prevent re-slotting if airfield lost
		return 
	end
	
	if event.id == 10 then -- S_EVENT_BASE_CAPTURED
		if cfxSSBClient.verbose then
			local place = event.place 
			
			trigger.action.outText("+++SSB: CAPTURE EVENT: <" .. place:getName() .. "> now owned by <" .. place:getCoalition() .. "> -- RESETTING SLOTS", 30)
		end
		cfxSSBClient.setSlotAccessByAirfieldOwner()
	end

-- write down player names and planes
	if event.id == 15 then -- birth
		if not event.initiator then return end 
		local theUnit = event.initiator -- we know this exists
		local uName = theUnit:getName()
		if not uName then return end 
		-- player entered unit? 
		-- check if this is a cloned impostor
		if not theUnit.getPlayerName then 
			if cfxSSBClient.verbose then 
				trigger.action.outText("+++SSBC: non-player 'client' " .. uName .. " detected, ignoring.", 30)
			end
			return
		end
		local playerName = theUnit:getPlayerName()
		if not playerName then 
			return -- NPC plane
		end 
		-- remember this unit as player controlled plane
		-- because player and plane can easily disconnect
		cfxSSBClient.playerPlanes[uName] = playerName
		if cfxSSBClient.verbose then 
			trigger.action.outText("+++SSBC:SU: noted " .. playerName .. " piloting player unit " .. uName, 30)
		end 
		-- mark it as occupied to player won't get kicked until they
		-- leave the unit 
		cfxSSBClient.occupiedUnits[uName] = playerName
		return 
	end
	
	if event.id == 5 then -- crash PRE-processing 
		if not event.initiator then return end
		local theUnit = event.initiator 
		local uName = theUnit:getName()
		cfxSSBClient.occupiedUnits[uName] = nil -- no longer occupied
		cfxSSBClient.setSlotAccessForUnit(theUnit) -- prevent re-slotting if airfield lost
	end

	if cfxSSBClient.singleUse and event.id == 5 then -- crash
		--if not event.initiator then return end 
		local theUnit = event.initiator 
		local uName = theUnit:getName()
		if not uName then return end
		local theGroup = theUnit:getGroup()
		if not theGroup then return end 
		-- see if a player plane
		local thePilot = cfxSSBClient.playerPlanes[uName]
		if not thePilot then 
			-- ignore. not a player plane
			if cfxSSBClient.verbose then 
				trigger.action.outText("+++SSBC:SU: ignored crash for NPC unit <" .. uName .. ">", 30)
			end 
			return 
		end
		-- if we get here, a player-owned plane has crashed 
		local gName = theGroup:getName()
		if not gName then return end 
		
		-- block this slot. 
		trigger.action.setUserFlag(gName, cfxSSBClient.disabledFlagValue)
		cfxSSBClient.slotState[gName] = cfxSSBClient.disabledFlagValue
		-- remember this plane to not re-enable if 
		-- airfield changes hands later 
		cfxSSBClient.crashedGroups[gName] = thePilot -- set to crash pilot 
		if cfxSSBClient.verbose then 
			trigger.action.outText("+++SSBC:SU: Blocked slot for group <" .. gName .. ">", 30)
		end 
		
		if cfxSSBClient.reUseAfter > 0 then 
			-- schedule re-opening this slot in <x> seconds
			timer.scheduleFunction(
				cfxSSBClient.reOpenSlotForGroupNamed, 
				{gName}, 
				timer.getTime() + cfxSSBClient.reUseAfter
				)
		end
	end
end

function cfxSSBClient.update()
	-- first, re-schedule me in one minute 
	timer.scheduleFunction(cfxSSBClient.update, {}, timer.getTime() + 60)
	
	-- now establish all slot blocks 
	cfxSSBClient.setSlotAccessByAirfieldOwner()
	
	-- show occupied planes
	if cfxSSBClient.verbose then 
		for uName, pName in pairs (cfxSSBClient.occupiedUnits) do 
			trigger.action.outText("+++ssbc: <" .. uName .. "> occupied by <" .. pName .. ">", 30)
		end
	end
end

function cfxSSBClient.dmlUpdate()
	-- first, re-schedule me in one second 
	timer.scheduleFunction(cfxSSBClient.dmlUpdate, {}, timer.getTime() + 1)
	
	for idx, theZone in pairs (cfxSSBClient.clientZones) do 
		-- see if we received any signals on out inputs
		if theZone.ssbOpen and cfxZones.testZoneFlag(theZone, theZone.ssbOpen, theZone.ssbTriggerMethod, "lastSsbOpen") then 
			if theZone.verbose then 
				trigger.action.outText("+++ssbc: <" .. theZone.name .. "> open input triggered for <" .. theZone.afName .. ">", 30)
			end
			cfxSSBClient.openAirFieldNamed(theZone.afName)
		end
		
		if theZone.ssbClose and cfxZones.testZoneFlag(theZone, theZone.ssbClose, theZone.ssbTriggerMethod, "lastSsbClose") then 
			if theZone.verbose then 
				trigger.action.outText("+++ssbc: <" .. theZone.name .. "> close input triggered for <" .. theZone.afName .. ">", 30)
			end
			cfxSSBClient.closeAirfieldNamed(theZone.afName)
		end
	end
end


-- pre-process static player data to minimize 
-- processor load on checks
function cfxSSBClient.processPlayerData()
	cfxSSBClient.playerGroups = cfxGroups.getPlayerGroup()
	local pGroups = cfxSSBClient.playerGroups
	local filteredPlayers = {}
	for idx, theGroup in pairs(pGroups) do
		if theGroup.airfield ~= nil or cfxSSBClient.keepInAirGroups or 
		cfxSSBClient.singleUse then 
			-- only transfer groups that have airfields (or also keepInAirGroups or when single-use)
			-- attached. Ignore the rest as they are 
			-- always fine
			table.insert(filteredPlayers, theGroup)
		end
	end
	cfxSSBClient.playerGroups = filteredPlayers
end

-- add airfield information to each player group
function cfxSSBClient.processGroupData()
	local pGroups = cfxGroups.getPlayerGroup() -- we want the group.name attribute
	for idx, theGroup in pairs(pGroups) do
		-- we always use the first player's plane as referenced
		local playerData = theGroup.playerUnits[1]
		local theAirfield = nil
		local delta = -1
		local action = playerData.action 
		if not action then action = "<NIL>" end 
		-- see if the data has any of the slot-interesting actions
		if dcsCommon.arrayContainsString(cfxSSBClient.slotActions, action ) then 
			-- yes, fetch the closest airfield 
			theAirfield, delta = cfxSSBClient.getClosestAirbaseTo(playerData.point)
			local afName = theAirfield:getName()
			if cfxSSBClient.verbose then 
				trigger.action.outText("+++SSB: group: " .. theGroup.name .. " closest to AF " .. afName .. ": " .. math.floor(delta) .. "m" , 30)
			end 
			if delta > cfxSSBClient.maxAirfieldRange then 
				-- forget airfield
				 theAirfield = nil
				if cfxSSBClient.verbose then 
					trigger.action.outText("+++SSB: group: " .. theGroup.name .. " unlinked - too far from airfield" , 30)
				end 
			end
			theGroup.airfield = theAirfield
		else 
			if cfxSSBClient.verbose then 
				trigger.action.outText("+++SSB: group: " .. theGroup.name .. " start option " .. action .. " does not concern SSB", 30)
			end 
		end
	end
end

--
-- read config zone
--
function cfxSSBClient.readConfigZone()
	-- note: must match exactly!!!!
	local theZone = cfxZones.getZoneByName("SSBClientConfig") 
	if not theZone then 
		trigger.action.outText("+++SSBC: no config zone!", 30) 
		return 
	end 
	
	trigger.action.outText("+++SSBC: found config zone!", 30) 
	
	cfxSSBClient.verbose = cfxZones.getBoolFromZoneProperty(theZone, "verbose", false)
	
	-- single-use
	cfxSSBClient.singleUse = cfxZones.getBoolFromZoneProperty(theZone, "singleUse", false) -- use airframes only once? respawn after kick must be disabled in ssb
	cfxSSBClient.reUseAfter = cfxZones.getNumberFromZoneProperty(theZone, "reUseAfter", -1)
	
	-- airfield availability 
	cfxSSBClient.allowNeutralFields = cfxZones.getBoolFromZoneProperty(theZone, "allowNeutralFields", false)
	
	cfxSSBClient.maxAirfieldRange = cfxZones.getNumberFromZoneProperty(theZone, "maxAirfieldRange", 3000) -- meters, to find attached airfield

	-- optimization 
	
	cfxSSBClient.keepInAirGroups = cfxZones.getBoolFromZoneProperty(theZone, "keepInAirGroups", false)
	
	-- SSB direct control. 
	-- USE ONLY WHEN YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING
	
	cfxSSBClient.enabledFlagValue = cfxZones.getNumberFromZoneProperty(theZone, "enabledFlagValue", 0)
	
	cfxSSBClient.disabledFlagValue = cfxZones.getNumberFromZoneProperty(theZone, "disabledFlagValue", cfxSSBClient.enabledFlagValue + 100)
end

--
-- load / save 
--
function cfxSSBClient.saveData()
	local theData = {}
	local states = dcsCommon.clone(cfxSSBClient.slotState)
	local crashed = dcsCommon.clone(cfxSSBClient.crashedGroups)
	local closed = dcsCommon.clone(cfxSSBClient.closedAirfields)
	theData.states = states
	theData.crashed = crashed 
	theData.closed = closed 
	return theData
end

function cfxSSBClient.loadData()
	if not persistence then return end 
	local theData = persistence.getSavedDataForModule("cfxSSBClient")
	if not theData then 
		if cfxSSBClient.verbose then 
			trigger.action.outText("+++cfxSSB: no save date received, skipping.", 30)
		end
		return
	end
	
	cfxSSBClient.slotState = theData.states
	if not cfxSSBClient.slotState then
		trigger.action.outText("SSBClient: nil slot state on load", 30)
		cfxSSBClient.slotState = {} 
	end
	for slot, state in pairs (cfxSSBClient.slotState) do 
		trigger.action.setUserFlag(slot, state)
		if state > 0 and cfxSSBClient.verbose then 
			trigger.action.outText("SSB: blocked <" .. slot .. "> on load", 30)
		end
	end
	if theData.crashed then 
		cfxSSBClient.crashedGroups = theData.crashed 
		if not cfxSSBClient.crashedGroups then 
			cfxSSBClient.crashedGroups = {} 		
			trigger.action.outText("SSBClient: nil crashers on load", 30)
		end
	end

	if theData.closed then 
		cfxSSBClient.closedAirfields = theData.closed 
	end
	
end

--
-- start
--
function cfxSSBClient.start()
	-- verify modules loaded 
	if not dcsCommon.libCheck("cfx SSB Client", 
		cfxSSBClient.requiredLibs) then
		return false 
	end
	
	-- read config zone if present 
	cfxSSBClient.readConfigZone()
	
	-- install callback for events in DCS
	world.addEventHandler(cfxSSBClient)
	
	-- process group data to attach airfields 
	cfxSSBClient.processGroupData()
	
	-- process player data to minimize effort and build cache
	-- into cfxSSBClient.playerGroups
	cfxSSBClient.processPlayerData()
	
	-- process ssbc zones 
	-- for in-mission DML interface
	local attrZones = cfxZones.getZonesWithAttributeNamed("ssbClient")
	for k, theZone in pairs(attrZones) do 
		cfxSSBClient.createClientZone(theZone) -- process attributes
		cfxSSBClient.addClientZone(theZone) -- add to list
	end
	
	-- install a timed update just to make sure
	-- and start NOW
	timer.scheduleFunction(cfxSSBClient.update, {}, timer.getTime() + 1)
	
	-- start dml update (on a different timer
	cfxSSBClient.dmlUpdate()
	 
	-- now turn on ssb 
	trigger.action.setUserFlag("SSB",100)
	
	-- persistence: load states 
	if persistence then 
		-- sign up for persistence 
		callbacks = {}
		callbacks.persistData = cfxSSBClient.saveData
		persistence.registerModule("cfxSSBClient", callbacks)
		-- now load my data 
		cfxSSBClient.loadData()
	end
	
	-- say hi!
	trigger.action.outText("cfxSSBClient v".. cfxSSBClient.version .. " running, SBB enabled", 30)
	
	
	return true 
end

if not cfxSSBClient.start() then 
	trigger.action.outText("cfxSSBClient v".. cfxSSBClient.version .. " FAILED loading.", 30)
	cfxSSBClient = nil
end

--[[--
  possible improvements: 
	- use explicitBlockList that with API. planes on that list are always blocked. Use this for special effects, such as allowing a slot only to open from scripts, e.g. when a condition is met like money or goals reached
   
-]]--