Add get_fc() and set_fc() commands

get_fc: returns a table of each wagon's FC codes
set_fc: set a table to overwrite the FC codes of a train's wagons

2 files changed, 50 insertions, 7 deletions

diff --git a/advtrains_luaautomation/README.md b/advtrains_luaautomation/README.md
index 67a4b80..a885075 100644
--- a/advtrains_luaautomation/README.md
+++ b/advtrains_luaautomation/README.md
@@ -255,7 +255,10 @@ In addition to the above environment functions, the following functions are avai
 	The interlocking system uses this property for Automatic Routesetting.
 
 #### Shunting Functions and Variables
-There are several functions available especially for shunting operations. Some of these functions make use of Freight Codes (FC) set in the Wagon Properties of each wagon and/or locomotive:
+There are several functions available especially for shunting operations.
+Some of these functions make use of Freight Codes (FC) set in the Wagon Properties of each wagon and/or locomotive.
+FCs are composed of codes separated by exclamation marks (`!`), for instance `"foo!bar!baz"`.
+Each wagon has a current FC, indicating its next destination.
 
  - `split_at_index(index, atc_command)`
 	Splits the train at the specified index, into a train with index-1 wagons and a second train starting with the index-th wagon. The `atc_command` specified is sent to the second train after decoupling. `"S0"` or `"B0"` is common to ensure any locomotives in the remaining train don't continue to move.
@@ -266,6 +269,18 @@ There are several functions available especially for shunting operations. Some o
 	Command: `split_at_index(4,"S0")`  
 	Result: first train (continues at previous speed): `"foo","foo","foo"`, second train (slows at S0): `"bar","bar","bar"`
 
+ - `get_fc()`
+	Returns a table with the entire FC list for each wagon in the train.  
+	Command: `get_fc()`  
+	Result: `{"", "foo!bar", "testing", "fc_1!fc_2!fc_3!?", "hello_world"}`
+	
+ - `set_fc(fc_list)`
+	Overwrites the FC list according to a table `fc_list`. A false or nil entry will leave the wagon unaffected, however all others will be overwritten.
+	Useful for mass-programming freight trains that use FC-shunting instead of walking to each wagon individually.  
+	Example: train has FC lists: `"", "foo!bar", "testing", "fc_1!fc_2!fc_3!?", "hello_world"`  
+	Command: `set_fc({"", "foo!turtle", nil, "4tehlulz", false})`  
+	Result: `""` `"foo!turtle"` `"testing"` `"4tehlulz"` `"hello_world"`
+
  - `split_at_fc(atc_command, len)`
 	Splits the train in such a way that all cars with non-empty current FC of the first part of the train have the same FC. The
 	`atc_command` specified is sent to the rear part, as with	split_at_index. It returns the fc of the cars of the first part.
@@ -289,15 +304,11 @@ There are several functions available especially for shunting operations. Some o
 	first part of the train as above.
 
  - `step_fc()`
-	Steps the FCs of all train cars forward. FCs are composed of codes
-	separated by exclamation marks (`!`), for instance
-	`"foo!bar!baz"`. Each wagon has a current FC, indicating its next
-	destination. Stepping the freight code forward, selects the next
-	code after the !. If the end of the string is reached, then the
+	Steps the FCs of all train cars forward, selecting the next
+	code after the `!`. If the end of the string is reached, then the
 	first code is selected, except if the string ends with a question
 	mark (`?`), then the order is reversed.
 
-
  - `train_length()`
 	returns the number of cars the train is composed of.
 
diff --git a/advtrains_luaautomation/atc_rail.lua b/advtrains_luaautomation/atc_rail.lua
index 5dde99c..aac11f0 100644..100755
--- a/advtrains_luaautomation/atc_rail.lua
+++ b/advtrains_luaautomation/atc_rail.lua
@@ -91,6 +91,38 @@ function r.fire_event(pos, evtdata, appr_internal)
 			if not train_id then return false end
 			advtrains.train_step_fc(train)
 		end,
+		get_fc = function()
+			if not train_id then return end
+			local fc_list = {}
+			for index,wagon_id in ipairs(train.trainparts) do
+				fc_list[index] = table.concat(advtrains.wagons[wagon_id].fc,"!") or ""
+			end
+			return fc_list
+		end,
+		set_fc = function(fc_list)
+			assertt(fc_list, "table")
+			if not train_id then return false end
+			-- safety type-check for entered values
+			for _,v in ipairs(fc_list) do
+				if v and type(v) ~= "string" then
+					error("FC entries must be a string")
+					return
+				end
+			end
+			for index,wagon_id in ipairs(train.trainparts) do
+				if fc_list[index] then -- has FC to enter to this wagon
+					local data = advtrains.wagons[wagon_id]
+					if data then -- wagon actually exists
+						for _,wagon in pairs(minetest.luaentities) do -- find wagon entity
+							if wagon.is_wagon and wagon.initialized and wagon.id==wagon_id then
+								wagon.set_fc(data,fc_list[index]) -- overwrite to new FC
+								break -- no point cycling through every other entity. we found our wagon
+							end
+						end
+					end
+				end
+			end
+		end,
 		set_shunt = function()
 			-- enable shunting mode
 			if not train_id then return false end