empty variables can now be deleted

fs_edit_general.lua

@@ -994,7 +994,11 @@ yl_speak_up.input_fs_edit_option_related = function(player, formname, fields,
 	-- show var usuage - but this time from the edit dialog for that precondition or effect
 	elseif(fields.show_var_usage_edit_element and x_id) then
 		local dialog = yl_speak_up.speak_to[pname].dialog
-		local element = dialog.n_dialogs[d_id].d_options[o_id][ element_list_name ][ x_id ]
+		local element = nil
+		-- x_id may be "new" and this may be the first element in element_list_name
+		if(dialog.n_dialogs[d_id].d_options[o_id][ element_list_name ]) then
+			element = dialog.n_dialogs[d_id].d_options[o_id][ element_list_name ][ x_id ]
+		end
 		if(not(element) or data.variable_name) then
 			element = {}
 			element[ id_prefix.."variable"] = data.variable_name
@@ -1019,16 +1023,12 @@ yl_speak_up.input_fs_edit_option_related = function(player, formname, fields,
 		end
 	-- allow to delete unused variables
 	elseif(fields.delete_unused_variable) then
-		-- try to delete the variable
+		-- try to delete the variable (button comes from the show usage of variable formspec)
-		local res = yl_speak_up.del_quest_variable(pname, data.variable_name)
+		local text = yl_speak_up.del_quest_variable(pname, data.variable_name, nil)
-		local text = "Deleted successfully."
-		if(not(res)) then
-			text = "Error: Variable could not be deleted."
-		end
 		yl_speak_up.show_fs(player, "msg", {
 			input_to = "yl_speak_up:"..formspec_input_to,
-			formspec = "size[8,2]"..
+			formspec = "size[10,2]"..
-				"label[0.2,0.5;Trying to delete variable \""..
+				"label[0.2,0.0;Trying to delete variable \""..
 					minetest.formspec_escape(tostring(data.variable_name))..
 					"\":\n"..text.."]"..
 				"button[1.5,1.5;2,0.9;back_from_error_msg;Back]"})

quest_api.lua

@@ -73,16 +73,55 @@ end
 
 
 -- accidentally created or no longer needed variables need to be deleted somehow
-yl_speak_up.del_quest_variable = function(owner_name, variable_name)
+-- force_delete if set, the variable will be deleted no matter what; this is for
-	local k = yl_speak_up.restore_complete_var_name(variable_name, owner_name)
+--              manual maintenance and not used in this mod
+yl_speak_up.del_quest_variable = function(owner_name, variable_name, force_delete)
 	if(not(owner_name) or not(variable_name)) then
-		return false
+		return " could not be deleted. Parameters mismatch."
+	end
+	local var_name = yl_speak_up.restore_complete_var_name(variable_name, owner_name)
+	if(not(var_name) or not(yl_speak_up.player_vars[ var_name ])) then
+		return text.." does not exist."
+	end
+	local text = "Variable \""..minetest.formspec_escape(var_name).."\""
+	-- forcefully delete - even if the variable is still beeing used
+	if(force_delete) then
+		yl_speak_up.player_vars[ k ] = nil
+		yl_speak_up.save_quest_variables(true)
+		return text.." deleted by force."
+	end
+	-- check if the player really owns the variable: not that important because only unused
+	-- variables can be deleted;
+	-- check if the variable is used by an NPC
+	local var_data = yl_speak_up.player_vars[ var_name ]
+	if(var_data["$META$"] and var_data["$META$"]["used_by_npc" ]
+	  and type(var_data["$META$"]["used_by_npc" ]) == "table") then
+		for k, v in pairs(var_data["$META$"]["used_by_npc" ]) do
+			if(k) then
+				return text.." could not be deleted.\nIt is used by at least one NPC."
+			end
+		end
+	end
+	-- check if the variable is used by a node position (for quests)
+	if(var_data["$META$"] and var_data["$META$"]["used_by_node_pos" ]
+	  and type(var_data["$META$"]["used_by_node_pos" ]) == "table") then
+		for k, v in pairs(var_data["$META$"]["used_by_node_pos" ]) do
+			if(k) then
+				return text.." could not be deleted.\nIt is used by at least one node pos."
+			end
+		end
+	end
+	-- check if the variable has any values stored
+	for k, v in pairs(var_data) do
+		if(k and k ~= "$META$") then
+			return text.." could not be deleted.\nIt contains at least one stored value."
+		end
 	end
 	-- actually delete the variable
-	yl_speak_up.player_vars[ k ] = nil
+	yl_speak_up.player_vars[ var_name ] = nil
 	-- a variable was deleted - that deserves a forced save
 	yl_speak_up.save_quest_variables(true)
-	return true
+	return text.." deleted successfully."
 end
 
 
@@ -256,8 +295,25 @@ yl_speak_up.input_fs_manage_variables = function(player, formname, fields)
 		var_name = ""
 	end
 
-	-- revoke read or write access to a variable
+
+	-- delete (empty) variable
 	if(fields
+	  and ((fields.delete_variable and fields.delete_variable ~= "")
+	    or (fields.delete_unused_variable and fields.delete_unused_variable ~= ""))
+	  and var_name) then
+		local text = yl_speak_up.del_quest_variable(pname, var_name, nil)
+		yl_speak_up.show_fs(player, "msg", {
+			input_to = "yl_speak_up:manage_variables",
+                        formspec = "size[10,2]"..
+                                "label[0.2,0.0;Trying to delete variable \""..
+                                        minetest.formspec_escape(tostring(var_name))..
+                                        "\":\n"..text.."]"..
+                                "button[1.5,1.5;2,0.9;back_from_msg;Back]"})
+
+		return
+
+	-- revoke read or write access to a variable
+	elseif(fields
 	  and ((fields.revoke_player_var_read_access  and fields.revoke_player_var_read_access ~= "")
 	    or (fields.revoke_player_var_write_access and fields.revoke_player_var_write_access ~= ""))
 	  and var_name) then
@@ -372,7 +428,6 @@ yl_speak_up.input_fs_manage_variables = function(player, formname, fields)
 		yl_speak_up.show_fs(player, "manage_variables")
 		return
 
-	-- TODO: delete variable
 	-- a var name was selected in the dropdown list
 	elseif(fields and fields.list_var_names and fields.list_var_names ~= "") then
 		-- show the same formspec again, with a diffrent variable selected
@@ -402,7 +457,8 @@ yl_speak_up.get_fs_manage_variables = function(player, param)
 	-- "Add variable:" is currently selected
 	local additional_buttons = ""
 	if(not(yl_speak_up.speak_to[pname].tmp_index_variable)
-	   or yl_speak_up.speak_to[pname].tmp_index_variable == 1) then
+	   or yl_speak_up.speak_to[pname].tmp_index_variable == 1
+	   or not(var_list[ yl_speak_up.speak_to[pname].tmp_index_variable - 1])) then
 		yl_speak_up.speak_to[pname].tmp_index_variable = 1
 		additional_buttons = "button[11.4,1.9;2.5,0.9;add_variable;Create variable]"..
 			"tooltip[add_variable;Create a new varialbe with the name\n"..
@@ -785,7 +841,8 @@ yl_speak_up.get_npc_users_of_variable = function(var_name)
 	if(not(var_name)
 	  or not(yl_speak_up.player_vars[ var_name ])
 	  or not(yl_speak_up.player_vars[ var_name ][ "$META$"])
-	  or not(yl_speak_up.player_vars[ var_name ][ "$META$"][ "used_by_npc" ])) then
+	  or not(yl_speak_up.player_vars[ var_name ][ "$META$"][ "used_by_npc" ])
+	  or type(yl_speak_up.player_vars[ var_name ][ "$META$"][ "used_by_npc" ]) ~= "table") then
 		return {}
 	end
 	local npc_list = {}
@@ -875,7 +932,6 @@ yl_speak_up.get_list_of_usage_of_variable = function(var_name, pname, check_prec
 				minetest.colorize("#55FF55", tostring(count_changed).." (Ef)fects")..
 				".]")
 	elseif(not(is_internal_var)) then
-		-- TODO: make delete_unused_variable work
 		table.insert(formspec,
 			"button[0.2,30.6;56.6,1.2;delete_unused_variable;"..
 				minetest.formspec_escape("Delete this unused variable \""..