Affiche seulement la première ligne de la description des items

- Ajoute message de chargement du mod dans le journal "action"

README.md

@@ -15,87 +15,86 @@ Nodes
 
 Using the Exchange
 ==================
-Main Screen
+Overview
 -----------
-The first screen you see is where you can search and post new buy/sell orders.
-Here is an overview of each element:
- - Market Summary - Pressing this will take you to the market summary screen.
- - Your Orders - This will take you to a screen where you can view and cancel
- your existing orders.
- - Item - This field is for entering the item name (e.g. default:cobble) of the
- item you want to search or post an order for.
- - Amount - This field is for entering how many of the item you want to buy/sell
- when posting an order. It has no purpose in searches.
- - Select Item - This button takes you to a screen for choosing your item
- graphically, instead of manually typing an item name.
- - Rate - This field is for entering the desired price per item when posting an
- order. For buy orders, this is the maximum price - your order will also accept
- items that are cheaper. For sell orders, this is the minimum price - your
- order will also accept buyers that are willing to pay more. The Rate field has
- no effect on searches
- - Search - This button searches existing orders for the selected item. If you
- have the "Sell" box checked, it will only display buy orders, and will display
- them in descending rate. If you have the box unchecked, it will show sell
- orders in order of ascending rate.
- - Post Order - This posts a new order for the item with the given amount and
- rate. If the "Sell" box is checked, this is a sell order, so the exchange will
- remove the items from your inventory. If it's unchecked, you are making a buy
- order, so it will deduct credits from your account. If there are already
- matching orders, it will immediately fill your order up to the amount possible,
- and the remainder will stay as a new order.
- - Sell - This checkbox determines what kind of orders to search for, and also
- what kind of order you are posting.
- - Search Results - This will display the results of your search. Clicking on an
- element here will automatically fill the "Amount" and "Rate" fields, so that if
- you click "Post Order", it will match the order you clicked.
+At the top of the exchange form there are four tabs: Market Summary, Buy, Sell,
+and Your Orders. Pressing each tab will take you to the indicated screen as
+described below.
 
 Market Summary
 --------------
 This summarizes the various items available on the exchange. From left to right,
 the columns display the item name, the description (what is shown in inventory),
-the amount requested by buyers, the maximum rate offered by buyers, the amount
-offered by sellers, and the minimum rate offered by sellers. It is updated
-periodically.
+the tool wear if applicable, the amount requested by buyers, the maximum rate
+offered by buyers, the amount offered by sellers, and the minimum rate offered
+by sellers. It is updated periodically.
+
+Buy
+-----------
+The upper-left corner shows the open order book for the selected item,
+consisting of the three best sell offers (lowest asking price and least tool
+wear) followed by the three best buy offers (highest offer price and highest
+acceptable tool wear). To the right is an image of the selected item, entry
+fields for the quantity and offer price, and a drop-down field for the desired
+tool wear: "New" (no wear), "Good" (up to 10% wear), "Worn" (up to 50% wear),
+and "Junk" (any amount of wear). To qualify, a seller must offer an item with
+wear equal to or less than the indicated amount (e.g. if you select "Good" you
+may receive an item with only 5% wear, but not one 15% worn). Similarly, the
+offer price is the highest price you are willing to pay; in practice you may
+pay less depending on the open sell orders. Orders are always fulfilled at the
+price listed in the open order book.
+
+At the bottom of the form is a grid similar to the creative inventory. You can
+page through the available items using the "<<" and ">>" buttons and select the
+item you wish to buy simply by clicking on it.
+
+To finalize the order, press the "Place Bid" button. Note that it is permitted
+to enter an order which exceeds your available funds at the time the order is
+placed. As matching sell orders are located, the order will be fulfulled until
+there are insufficient funds to cover the next item, at which point the
+remainder of the order will be cancelled.
+
+Sell
+-----------
+As with the Buy screen, the upper-left corner shows the open order book for
+the selected item. Instead of a static image, the selected item appears as a
+1x1 inventory. At the bottom of the screen is the standard 8x4 player
+inventory. To choose the type and quantity of items to sell, move the items
+from your player inventory to the exchange inventory. Below the exchange
+inventory is an entry field for the desired asking price. To finalize the
+order, press the "Sell" button. As with buy orders, the asking price is the
+lowest price you are willing to accept, and you may receive a higher price
+depending on the open buy orders.
+
+Unsold items in the exchange inventory are returned to the player inventory
+when the form is closed, or to the player's Inbox if the inventory is full.
+(However, items in the exchange inventory at the time of a server crash, or
+other abnormal condition, may be lost.)
 
 Your Orders
 -----------
 This screen lets you see and cancel your orders. To cancel an order, click the
-order and press the "Cancel" button.
-
-Select Item
------------
-This displays a creative-style inventory menu for selecting an item for searches
-or posting orders. To select an item, drag it from the inventory to the box near
-the bottom of the form
+order and press the "Cancel" button. If the order was sell order, the items
+held in "escrow" are returned to your player inventory. If any of the items do
+not fit in the inventory they are placed in your Inbox instead to be claimed
+later.
 
 Buying/Selling
 ==============
 Once you have opened the exchange, you have a few options. If you don't already
 know what you want to buy or sell, you can look at the Market Summary to get a
 glance at what people are offering. After you have decided on what you are
-going to do, return to the exchange page.
+going to do, return to the Buy or Sell page.
 
-If you are selling an item, you should check the "Sell" checkbox. Otherwise,
-leave it unchecked. Next, you need to select the item you want to deal in. There
-are two ways: typing the item name (e.g. default:cobble) in manually to the item
-field, or using the "Select Item" menu. If you haven't already decided on a price,
-or you want to make sure your order is filled quickly, you can conduct a search.
-To do this, click the "Search" button. This will give you a list of results. If
-you checked the "Sell" box, then these will be buy orders, and will show the
-maximum price per item each buyer is willing to accept. Otherwise, these will be
-sell orders, displaying the minimum price each seller will accept. If you click
-on a search result, it will automatically fill your Amount and Rate fields to
-match.
-
-The Amount and Rate fields are used to decide how much and how expensively you
-want to make your order. When selling, the Rate field is the minimum price you
-will accept. When buying, it is the maximum. Once everything is filled out how
-you want it, press the "Post Order" button. If there are matching offers (when
-you post a buy/sell offer, there are one or more sell/buy offers with a price
-at least as good), then that part of your offer will immediately be filled. For
-example, if you post a buy order for 10 cobblestone at 5 credits each, and there
-is a sell offer for 5 cobblestone 3 credits each, it will give you 5 cobble
-immediately, and leave an order on the exchange for 5 more cobblestone.
+When selling, the Ask field is the minimum price you will accept for each
+item. When buying, the Bid field determines the maximum amount you are willing
+to pay. If there are matching offers (i.e. there are one or more offers with a
+price at least as good and a compatible tool wear level), then that part of
+your offer will immediately be filled. For example, if you post a buy order
+for 10 cobblestone at 5 credits each, and there is a sell offer for 5
+cobblestone at 3 credits each, it will give you 5 cobble immediately at a
+total cost of 15 credits (the order-book price), and leave an order on the
+exchange for 5 more cobblestone at 5 credits each.
 
 Once your offer is on the exchange, you can view or cancel it from the "Your
 Orders" menu.

atm.lua

@@ -1,152 +1,170 @@
 -- A telling machine. Call this file with the exchange argument.
-local exchange = ...
+local exchange, formlib = ...
 
 local atm_form = "global_exchange:atm_form"
+local atm_pos = {}
 
-local main_menu =[[
-size[6,2]
-button[2,0;2,1;info;Account Info]
-button[4,0;2,1;wire;Wire Monies]
-button[1,1;4,1;transaction_log;Transaction Log]
-]]
+local unique = (function(unique_num)
+	return function()
+		unique_num = unique_num + 1
+		return unique_num
+	end
+end)(0)
 
+local coins_convert = {
+	["minercantile:copper_coin"]=1, ["minercantile:silver_coin"]=9, ["minercantile:gold_coin"]=81,
+	["maptools:copper_coin"]=1, ["maptools:silver_coin"]=9, ["maptools:gold_coin"]=81,
+	["bitchange:mineninth"]=729, ["bitchange:minecoin"]=6561, ["bitchange:minecoinblock"]=59049
+}
 
-local function logout(x,y)
-	return "button[" .. x .. "," .. y .. ";2,1;logout;Log Out]"
-end
-
-
-local function label(x,y,text)
-	return "label[" .. x .. "," .. y .. ";"
-		.. minetest.formspec_escape(text) .. "]"
-end
-
-local function field(x,y, w,h, name, label, default)
-	return "field[" .. x .. "," .. y .. ";" .. w .. "," .. h .. ";"
-		.. name .. ";" .. minetest.formspec_escape(label) .. ";"
-		.. minetest.formspec_escape(default) .. "]"
-end
-
-local unique_num = 1
-
-local function unique()
-	local ret = unique_num
-	unique_num = unique_num + 1
-
-	return ret
-end
-
-
-local function info_fs(p_name)
+local function deposit_fs(fs, p_name)
 	local balance = exchange:get_balance(p_name)
+	local spos = atm_pos[p_name].x..","..atm_pos[p_name].y..","..atm_pos[p_name].z
+
+	fs:size(8,9)
 	
-	local fs
 	if not balance then
-		fs = label(0.5,0.5, "You don't have an account.")
+		fs:label(0.5,0.5, "You don't have an account.")
 	else
-		fs = label(0.5,0.5, "Balance: " .. balance)
+		fs:label(0.5,0.5, "Balance: " .. balance)
+		fs:label(1,1,"Put your coins to credit your account")
+		fs:list(3.5,2.5, 1,1, "nodemeta:"..spos, "main")
+		fs:list(0,4, 8,4, "current_player", "main")
+		--fs("list[nodemeta:"..spos..";main;3.5,2.5;1,1;]"..
+		--		"list[current_player;main;0,4.85;8,1;]"..
+		--		"list[current_player;main;0,6.08;8,3;8]" ..
+		fs("listring[nodemeta:"..spos..";main]"..
+				"listring[current_player;main]"
+		)
 	end
 
-	return "size[4,3]" .. fs .. logout(0.5,2)
+	fs:button(1,2, 2,1, "logout", "Log Out")
 end
 
-
-local function wire_fs(p_name)
+local function info_fs(fs, p_name)
 	local balance = exchange:get_balance(p_name)
 
-	local fs = "size[4,5]" .. logout(0,4)
+	fs:size(4,3)
 
-	if not balance then
-		return fs .. label(0.5,0.5, "You don't have an account.")
+	if balance then
+		fs:label(0.5,0.5, "Balance: " .. balance)
+	else
+		fs:label(0.5,0.5, "You don't have an account.")
 	end
 
-	-- To prevent duplicates
-	return fs .. field(-100, -100, 0,0, "trans_id", "", unique()) ..
-		label(0.5,0.5, "Balance: " .. balance) ..
-		field(0.5,1.5, 2,1, "recipient", "Send to:", "") ..
-		field(0.5,2.5, 2,1, "amount", "Amount", "") ..
-		"button[2,4;2,1;send;Send]"
+	fs:button(1,2, 2,1, "logout", "Log Out")
 end
 
 
-local function send_fs(p_name, receiver, amt_str)
-	local fs = "size[7,3]"
+local function wire_fs(fs, p_name)
+	local balance = exchange:get_balance(p_name)
+
+	fs:size(4,5)
+
+	if balance then
+		-- To detect duplicate/stale form submission
+		fs:field(-100, -100, 0,0, "trans_id", "", unique())
+
+		fs:label(0.50,0.325, "Balance: " .. balance)
+		fs:field(0.75,1.750, 3,1, "recipient", "Send to:", "")
+		fs:field(0.75,3.000, 3,1, "amount", "Amount", "")
+
+		fs:button(0,4.25, 2,1, "logout", "Log Out")
+		fs:button(2,4.25, 2,1, "send", "Send")
+	else
+		fs:button(0,4, 2,1, "logout", "Back")
+		fs:label(0.5,0.5, "You don't have an account.")
+	end
+end
+
+
+local function send_fs(fs, p_name, receiver, amt_str)
+	fs:size(10,3)
+
+	fs:button(4,2, 2,1, "wire", "Back")
 
 	local amt = tonumber(amt_str)
+	local msg = nil
 
 	if not amt or amt <= 0 then
-		return fs .. label(0.5,0.5, "Invalid transfer amount.") ..
-			"button[0.5,2;2,1;wire;Back]"
+		msg = "Invalid transfer amount."
+	else
+		local succ, err = exchange:transfer_credits(p_name, receiver, amt)
+
+		if not succ then
+			msg = "Error: " .. err
+		else
+			msg = "Successfully sent " .. amt ..
+				" credits to " .. receiver .. "."
+		end
 	end
 
-	local succ, err = exchange:transfer_credits(p_name, receiver, amt)
-
-	if not succ then
-		return fs .. label(0.5,0.5, "Error: " .. err) ..
-			"button[0.5,2;2,1;wire;Back]"
-	end
-	return fs.. label(0.5,0.5, "Successfully sent " ..
-		amt .. " credits to " .. receiver) ..
-		"button[0.5,2;2,1;wire;Back]"
+	fs:label(0.5,0.5, msg)
 end
 
 
-local function log_fs(p_name)
-	local res = {
-		"size[8,8]label[0,0;Transaction Log]button[0,7;2,1;logout;Log Out]",
-		"tablecolumns[text;text]",
-		"table[0,1;8,6;log_table;Time,Message",
-	}
+local function log_fs(fs, p_name)
+	fs:size(14,8)
 
-	for i, entry in ipairs(exchange:player_log(p_name)) do
-		i = i*4
-		res[i] = ","
-		res[i+1] = tostring(entry.Time)
-		res[i+2] = ","
-		res[i+3] = entry.Message
+	fs:label(0,0, "Transaction Log")
+
+	fs:element("tablecolumns", "text", "text")
+
+	fs("table[0,0.75;13.75,6.75;log_table;Time,Message")
+	for _, entry in ipairs(exchange:player_log(p_name)) do
+		fs(","):escape_list(entry.Time, entry.Message)
 	end
-	res[#res+1] ="]"
+	fs("]")
 
-	return table.concat(res)
+	fs:button(6,7.5, 2,1, "logout", "Log Out")
+end
+
+
+local function main_menu_fs(fs, p_name)
+	fs:size(6,2)
+	fs:button(0,0.125, 2,1, "deposit", "Cash Deposit")
+	fs:button(2,0.125, 2,1, "info", "Account Info")
+	fs:button(4,0.125, 2,1, "wire", "Wire Monies")
+	fs:button(0.50,1.125, 5.0,1, "transaction_log", "Transaction Log")
+end
+
+
+local function show_atm_form(fs_fn, p_name, ...)
+	local fs = formlib.Builder()
+	fs_fn(fs, p_name, ...)
+	minetest.show_formspec(p_name, atm_form, tostring(fs))
 end
 
 
 local trans_ids = {}
 
-
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 	if formname ~= atm_form then return end
 	if fields.quit then return true end
 
 	local p_name = player:get_player_name()
 
-	local this_id = fields.trans_id
+	local this_id = tonumber(fields.trans_id)
 
-	if this_id and this_id == trans_ids[p_name] then
+	if this_id and trans_ids[p_name] and this_id <= trans_ids[p_name] then
+		-- Ignore duplicate/stale form submittal
 		return true
 	end
 
 	trans_ids[p_name] = this_id
 
 	if fields.logout then
-		minetest.show_formspec(p_name, atm_form, main_menu)
-	end
-
-	if fields.info then
-		minetest.show_formspec(p_name, atm_form, info_fs(p_name))
-	end
-
-	if fields.wire then
-		minetest.show_formspec(p_name, atm_form, wire_fs(p_name))
-	end
-
-	if fields.send then
-		minetest.show_formspec(p_name, atm_form,
-			send_fs(p_name, fields.recipient, fields.amount))
-	end
-
-	if fields.transaction_log then
-		minetest.show_formspec(p_name, atm_form, log_fs(p_name))
+		show_atm_form(main_menu_fs, p_name)
+	elseif fields.info then
+		show_atm_form(info_fs, p_name)
+	elseif fields.wire then
+		show_atm_form(wire_fs, p_name)
+	elseif fields.send then
+		show_atm_form(send_fs, p_name, fields.recipient, fields.amount)
+	elseif fields.transaction_log then
+		show_atm_form(log_fs, p_name)
+	elseif fields.deposit then
+		show_atm_form(deposit_fs, p_name)
 	end
 
 	return true
@@ -180,18 +198,19 @@ minetest.register_node("global_exchange:atm_bottom", {
 	selection_box = {
 		type = "fixed",
 		fixed = {
-			{-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
-			{-0.5, 0.5, -0.5, -0.375, 1.125, -0.25},
-			{0.375, 0.5, -0.5, 0.5, 1.125, -0.25},
-			{-0.5, 0.5, -0.25, 0.5, 1.5, 0.5},
-			{-0.5, 1.125, -0.4375, -0.375, 1.25, -0.25},
-			{0.375, 1.125, -0.4375, 0.5, 1.25, -0.25},
-			{-0.5, 1.25, -0.375, -0.375, 1.375, -0.25},
-			{0.375, 1.25, -0.375, 0.5, 1.375, -0.25},
-			{-0.5, 1.375, -0.3125, -0.375, 1.5, -0.25},
-			{0.375, 1.375, -0.3125, 0.5, 1.5, -0.25},
+			{-0.500, -0.500, -0.5000,  0.500, 0.500,  0.50},
+			{-0.500,  0.500, -0.5000, -0.375, 1.125, -0.25},
+			{ 0.375,  0.500, -0.5000,  0.500, 1.125, -0.25},
+			{-0.500,  0.500, -0.2500,  0.500, 1.500,  0.50},
+			{-0.500,  1.125, -0.4375, -0.375, 1.250, -0.25},
+			{ 0.375,  1.125, -0.4375,  0.500, 1.250, -0.25},
+			{-0.500,  1.250, -0.3750, -0.375, 1.375, -0.25},
+			{ 0.375,  1.250, -0.3750,  0.500, 1.375, -0.25},
+			{-0.500,  1.375, -0.3125, -0.375, 1.500, -0.25},
+			{ 0.375,  1.375, -0.3125,  0.500, 1.500, -0.25},
 		},
 	},
+	groups = {cracky=2, atm = 1},
 	on_place = function(itemstack, placer, pointed_thing)
 		local under = pointed_thing.under
 		local pos
@@ -230,10 +249,43 @@ minetest.register_node("global_exchange:atm_bottom", {
 			minetest.remove_node(pos2)
 		end
 	end,
-	groups = {cracky=2, atm = 1},
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("infotext", "ATM")
+		local inv = meta:get_inventory()
+		inv:set_size("main", 1)
+	end,
+	allow_metadata_inventory_put = function(pos, listname, index, stack, player)
+		local itname = stack:get_name()
+		if coins_convert[itname] ~= nil then
+			return stack:get_count()
+		end
+		return 0
+	end,
+	on_metadata_inventory_put = function(pos, listname, index, stack, player)
+		local itname = stack:get_name()
+		if coins_convert[itname] ~= nil then
+			local p_name = player:get_player_name()
+			local meta = minetest.get_meta(pos)
+			local inv = meta:get_inventory()
+			local nb = stack:get_count()
+			local amount = coins_convert[itname] * nb
+			local succ, msg = exchange:give_credits(p_name, amount, "Cash deposit (+"..amount..")")
+			if succ then
+				inv:set_stack(listname, index, nil)
+				minetest.log("action", p_name.." put "..nb.." "..stack:get_name() .. " to ATM at " .. minetest.pos_to_string(pos))
+				show_atm_form(deposit_fs, p_name)
+				--minetest.show_formspec(p_name, atm_form, deposit_fs(p_name))
+			else
+				minetest.log("error", p_name.." want to put "..nb.." "..stack:get_name().." to ATM at ".. minetest.pos_to_string(pos).." but: "..msg)
+			end
+		end
+	end,
 	on_rightclick = function(pos, _, clicker)
+		local p_name = clicker:get_player_name()
+		atm_pos[p_name] = pos
 		minetest.sound_play("atm_beep", {pos = pos, gain = 0.3, max_hear_distance = 5})
-		minetest.show_formspec(clicker:get_player_name(), atm_form, main_menu)
+		show_atm_form(main_menu_fs, clicker:get_player_name())
 	end,
 })
 
@@ -254,15 +306,15 @@ minetest.register_node("global_exchange:atm_top", {
 	node_box = {
 		type = "fixed",
 		fixed = {
-			{-0.5, -0.5, -0.5, -0.375, 0.125, -0.25},
-			{0.375, -0.5, -0.5, 0.5, 0.125, -0.25},
-			{-0.5, -0.5, -0.25, 0.5, 0.5, 0.5},
-			{-0.5, 0.125, -0.4375, -0.375, 0.25, -0.25},
-			{0.375, 0.125, -0.4375, 0.5, 0.25, -0.25},
-			{-0.5, 0.25, -0.375, -0.375, 0.375, -0.25},
-			{0.375, 0.25, -0.375, 0.5, 0.375, -0.25},
-			{-0.5, 0.375, -0.3125, -0.375, 0.5, -0.25},
-			{0.375, 0.375, -0.3125, 0.5, 0.5, -0.25},
+			{-0.500, -0.500, -0.5000, -0.375, 0.125, -0.25},
+			{ 0.375, -0.500, -0.5000,  0.500, 0.125, -0.25},
+			{-0.500, -0.500, -0.2500,  0.500, 0.500,  0.50},
+			{-0.500,  0.125, -0.4375, -0.375, 0.250, -0.25},
+			{ 0.375,  0.125, -0.4375,  0.500, 0.250, -0.25},
+			{-0.500,  0.250, -0.3750, -0.375, 0.375, -0.25},
+			{ 0.375,  0.250, -0.3750,  0.500, 0.375, -0.25},
+			{-0.500,  0.375, -0.3125, -0.375, 0.500, -0.25},
+			{ 0.375,  0.375, -0.3125,  0.500, 0.500, -0.25},
 		}
 	},
 	selection_box = {
@@ -278,10 +330,11 @@ minetest.register_node("global_exchange:atm_top", {
 minetest.register_craft( {
 	output = "global_exchange:atm",
 	recipe = {
-		{ "default:stone", "default:stone", "default:stone" },
+		{ "default:stone", "default:stone",      "default:stone" },
 		{ "default:stone", "default:gold_ingot", "default:stone" },
-		{ "default:stone", "default:stone", "default:stone" },
+		{ "default:stone", "default:stone",      "default:stone" },
 	}
 })
 
 minetest.register_alias("global_exchange:atm", "global_exchange:atm_bottom")
+-- vim:set ts=4 sw=4 noet:

digital_mailbox.lua

@@ -1,60 +1,61 @@
-
-local exchange = ...
+local exchange, formlib = ...
 
 local mailbox_form = "global_exchange:digital_mailbox"
 
 local mailbox_contents = {}
 local selected_index = {}
--- Map from player names to their most recent search result
 
+-- Map from player names to their most recent search result
 local function get_mail(p_name)
 	local mail_maybe = mailbox_contents[p_name]
-	if mail_maybe then
-		return mail_maybe
-	else
-		mailbox_contents[p_name] = {}
-		return mailbox_contents[p_name]
+
+	if not mail_maybe then
+		local _,res = exchange:view_inbox(p_name)
+		mail_maybe = res or {}
+		mailbox_contents[p_name] = mail_maybe
+		selected_index[p_name] = math.min(selected_index[p_name] or 0, #mail_maybe)
 	end
+
+	return mail_maybe
 end
 
 
-local function mk_inbox_list(results, x, y, w, h)
-	local res = {
-		"textlist[",
-		tostring(x),
-		",",
-		tostring(y),
-		";",
-		tostring(w),
-		",",
-		tostring(h),
-		";result_list;"
-	}
-
-	for i, row in ipairs(results) do
-		res[i*2+8] = row.Amount .. " " .. row.Item
-		res[i*2+9] = ","
-	end
-	res[#res+1] = "]"
-
-	return table.concat(res)
+local function wear_string(wear)
+	return "-" .. math.ceil(100 * wear / 65535) .. "%"
 end
 
 
-local function mk_mail_fs(p_name, results, err_str)
-	fs = "size[6,8]" ..
-		"label[0,0;Inbox]"
+local function mk_inbox_list(fs, results, x, y, w, h)
+	fs:textlist(x,y, w,h, "result_list", function(add_row)
+		for i, row in ipairs(results) do
+			local wear_suffix = nil
+			if row.Wear > 0 then
+				wear_suffix = " (" .. wear_string(row.Wear) .. ")"
+			end
+			add_row(row.Amount, " ", row.Item, wear_suffix)
+		end
+	end)
+end
+
+
+local function mk_mail_fs(fs, p_name, results, err_str)
+	fs:size(8,8)
+	fs:label(0,0, "Inbox")
+
 	if err_str then
-		fs = fs .. "label[3,0;Error: " .. err_str .. "]"
+		fs:label(3,0, "Error: " .. err_str)
 	end
 
-	return fs .. mk_inbox_list(results, 0, 1, 6, 6) ..
-		"button[0,7;2,1;claim;Claim]"
+	mk_inbox_list(fs, results, 0, 1, 7.75, 6.25)
+
+	fs:button(3,7.35, 2,1, "claim", "Claim")
 end
 
 
-local function show_mail(p_name, results, err_str)
-	minetest.show_formspec(p_name, mailbox_form, mk_mail_fs(p_name, results, err_str))
+local function show_mail(p_name, err_str)
+	local fs = formlib.Builder()
+	mk_mail_fs(fs, p_name, get_mail(p_name), err_str)
+	minetest.show_formspec(p_name, mailbox_form, tostring(fs))
 end
 
 
@@ -63,35 +64,6 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 	if fields.quit then return true end
 
 	local p_name = player:get_player_name()
-	local idx = selected_index[p_name]
-
-	if fields.claim
-	and idx then
-		local row = get_mail(p_name)[idx]
-
-		if row then
-			local stack = ItemStack(row.Item)
-			stack:set_count(row.Amount)
-
-			local p_inv = player:get_inventory()
-			if not p_inv:room_for_item("main", stack) then
-				show_mail(p_name, get_mail(p_name), "Not enough room.")
-				return true
-			end
-
-			local succ, res = exchange:take_inbox(row.Id, row.Amount)
-			if not succ then
-				show_mail(p_name, get_mail(p_name), res)
-			end
-
-			stack:set_count(res)
-
-			p_inv:add_item("main", stack)
-
-			table.remove(get_mail(p_name), idx)
-			show_mail(p_name, get_mail(p_name))
-		end
-	end
 
 	if fields.result_list then
 		local event = minetest.explode_textlist_event(fields.result_list)
@@ -101,22 +73,48 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		end
 	end
 
+	if fields.claim then
+		local idx = selected_index[p_name]
+		local row = get_mail(p_name)[idx]
+
+		if row then
+			local stack = ItemStack(row.Item)
+			stack:set_count(row.Amount)
+			stack:set_wear(row.Wear)
+
+			local p_inv = player:get_inventory()
+			local leftover = p_inv:add_item("main", stack)
+			local took_amount = row.Amount - leftover:get_count()
+
+			mailbox_contents[p_name] = nil
+
+			local succ, res = exchange:take_inbox(row.Id, took_amount)
+			if succ then
+				show_mail(p_name)
+			else
+				show_mail(p_name, res)
+			end
+		end
+	end
+
 	return true
 end)
 
 
 minetest.register_node("global_exchange:mailbox", {
 	description = "Digital Mailbox",
-	tiles = {"global_exchange_box.png",
+	tiles = {
+		"global_exchange_box.png",
 		"global_exchange_box.png",
 		"global_exchange_box.png^global_exchange_mailbox_side.png",
 	},
+	is_ground_content = false,
+	stack_max = 1,
 	groups = {cracky=2},
 	on_rightclick = function(pos, node, clicker)
 		local p_name = clicker:get_player_name()
-		local _,res = exchange:view_inbox(p_name)
-		mailbox_contents[p_name] = res
-		minetest.show_formspec(p_name, mailbox_form, mk_mail_fs(p_name, res))
+		mailbox_contents[p_name] = nil
+		show_mail(p_name)
 	end,
 })
 
@@ -125,7 +123,8 @@ minetest.register_craft( {
 	output = "global_exchange:mailbox",
 	recipe = {
 		{ "default:stone", "default:gold_ingot", "default:stone" },
-		{ "default:stone", "default:chest", "default:stone" },
-		{ "default:stone", "default:stone", "default:stone" },
+		{ "default:stone", "default:chest",      "default:stone" },
+		{ "default:stone", "default:stone",      "default:stone" },
 	}
 })
+-- vim:set ts=4 sw=4 noet:

exchange_machine.lua

@@ -1,35 +1,63 @@
+local exchange, formlib = ...
 
-local exchange = ...
 local search_cooldown = 2
 local summary_interval = 600
 
+local global_inv = nil
+
+-- NALC split() function
+local function split(str, sep)
+	if not str then return nil end
+	local result = {}
+	local regex = ("([^%s]+)"):format(sep)
+	for each in str:gmatch(regex) do
+		table.insert(result, each)
+	end
+	return result
+end
+
+local function is_integer(x)
+	return math.floor(x) == x
+end
+
+local function wear_string(wear)
+	if wear > 0 then
+		return "-" .. math.ceil(100 * wear / 65535) .. "%"
+	else
+		return "----"
+	end
+end
+
 local summary_fs = ""
 local function mk_summary_fs()
-	local res = {
-		"size[8,8]",
-		"label[0,0;Updated Periodically]",
-		"tablecolumns[text;text;text;text;text;text]",
-		"table[0,1;8,6;summary_table;",
-		"Item,Description,Buy Vol,Buy Max,Sell Vol,Sell Min"
-	}
+	local fs = formlib.Builder()
 
-	local all_items = minetest.registered_items
-	for i, row in ipairs(exchange:market_summary()) do
-		local n = #res+1
-		res[n] = "," .. row.item_name
-		local def = all_items[row.item_name] or {}
-		res[n+1] = "," .. (def.description or "Unknown Item")
-		res[n+2] = "," .. (row.buy_volume or 0)
-		res[n+3] = "," .. (row.buy_max or "N/A")
-		res[n+4] = "," .. (row.sell_volume or 0)
-		res[n+5] = "," .. (row.sell_min or "N/A")
-	end
+	fs:tablecolumns("text", "text", "text", "text", "text", "text", "text")
+	fs:table(0,0, 11.75,9, "summary_table", function(add_row)
+		add_row("Item",
+		        "Description",
+				"Wear",
+		        "Buy Vol",
+		        "Buy Max",
+		        "Sell Vol",
+		        "Sell Min")
 
-	res[#res+1] = "]"
-	res[#res+1] = "button[3,7;2,1;back;Back]"
+		local all_items = minetest.registered_items
+		for i, row in ipairs(exchange:market_summary()) do
+			local def = all_items[row.Item] or {}
+			add_row(row.Item,
+			        split(def.description, "\n")[1] or "Unknown Item",
+					wear_string(row.Wear),
+			        row.Buy_Volume  or 0,
+			        row.Buy_Max     or "N/A",
+			        row.Sell_Volume or 0,
+			        row.Sell_Min    or "N/A")
+		end
+	end)
 
-	summary_fs = table.concat(res)
+	summary_fs = tostring(fs)
 end
+
 minetest.after(0, mk_summary_fs)
 
 
@@ -42,26 +70,34 @@ minetest.register_globalstep(function(dtime)
 	end
 end)
 
-local summary_form = "global_exchange:summary"
-local function show_summary(p_name)
-	minetest.show_formspec(p_name, summary_form, summary_fs)
+
+local wear_levels = {
+	[1] = { index = 1, text = "New (-0%)",    wear = math.floor(0.00*65535) },
+	[2] = { index = 2, text = "Good (-10%)",  wear = math.floor(0.10*65535) },
+	[3] = { index = 3, text = "Worn (-50%)",  wear = math.floor(0.50*65535) },
+	[4] = { index = 4, text = "Junk (-100%)", wear = math.floor(1.00*65535) },
+}
+
+-- Allow lookup by text label as well as index
+for _,v in ipairs(wear_levels) do
+	wear_levels[tostring(v.text)] = v
 end
 
+
 local main_state = {}
--- ^ A per-player state for the main form. It contains these values:
---     old_fields: Keeps track of the fields before this update, when changing
---                 things slightly
---     search_results: The last search results the player obtained
---     last_search_time: The last time the player did a search. Used to implement
---                       a cooldown on searches
---     sell: A boolean whether the player has sell selected
+-- ^ A per-player state for the main form.
 
 minetest.register_on_joinplayer(function(player)
 	exchange:new_account(player:get_player_name()) --just to make sure
 	main_state[player:get_player_name()] = {
-		old_fields = {},
-		search_results = {},
-		last_search_time = 0,
+		tab            = 1,
+		buy_item       = "",
+		buy_wear       = wear_levels[1].text,
+		buy_price      = "",
+		buy_amount     = "1",
+		sell_price     = "",
+		buy_page       = 1,
+		selected_index = 0,
 	}
 end)
 
@@ -70,268 +106,268 @@ minetest.register_on_leaveplayer(function(player)
 end)
 
 
-local main_form = "global_exchange:exchange_main"
-
-
-local tablecolumns =
-	"tablecolumns[text;text;text;text;text;text]"
-
-
-local function table_from_results(results, x, y, w, h, selected)
-	local fs_tab
-
-	local function insert(str)
-		fs_tab[#fs_tab+1] = str
-	end
-
-	fs_tab = {
-		tablecolumns,
-		"table[" .. x .. "," .. y .. ";" .. w .. "," .. h .. ";",
-		"result_table;",
-		"Poster,Type,Item,Description,Amount,Rate"
-	}
-
-	local all_items = minetest.registered_items
-
-	for i, row in ipairs(results) do
-		insert(",")
-		insert(tostring(row.Poster))
-		insert(",")
-		insert(tostring(row.Type))
-		insert(",")
-		insert(tostring(row.Item))
-		insert(",")
-		local def = all_items[row.Item] or {}
-		insert(def.description or "Unknown Item")
-		insert(",")
-		insert(tostring(row.Amount))
-		insert(",")
-		insert(tostring(row.Rate))
-	end
-
-	if selected and selected ~= "" then
-		insert(";")
-		insert(selected)
-	end
-	insert("]")
-
-	return table.concat(fs_tab)
-end
-
-
-local function mk_main_fs(p_name, new_item, err_str, success)
-	local state = main_state[p_name]
-	if not state then return end -- Should have been initialized on player join
-
-	local old_fields = state.old_fields
-	local results = state.search_results
-	local item_def = new_item or old_fields.item or ""
-	local amount_def = old_fields.amount or ""
-	local rate_def = old_fields.rate or ""
-	local sell_def = state.sell or false
-	local selected_def = old_fields.selected or ""
-
-	local bal = exchange:get_balance(p_name)
-
-	local fs
-	if bal then
-		fs = "label[0,0;Balance: " .. bal .. "]"
-	else
-		fs = "label[0.2,0.5;Use an ATM to make your account.]"
-	end
-
-	fs = fs .. "button[4,0;2,1;summary;Market Summary]" ..
-		"button[6,0;2,1;your_orders;Your Orders]" ..
-		"field[0.2,1.5;3,1;item;Item: ;" .. item_def .. "]" ..
-		"field[3.2,1.5;3,1;amount;Amount: ;" .. amount_def .. "]" ..
-		"button[6,1;2,1.4;select_item;Select Item]" ..
-		"checkbox[5,3;sell;Sell;" .. tostring(sell_def) .. "]" ..
-		"field[0.2,2.5;2,1;rate;Rate: ;" .. rate_def .. "]" ..
-		"button[2,2;2,1.4;search;Search]" ..
-		"button[4,2;3,1.4;post_order;Post Order]"
-
-	if err_str then
-		fs = fs .. "label[0,3;Error: " .. err_str .. "]"
-	end
-
-	if success then
-		fs = fs .. "label[0,3;Success!]"
-	end
-
-	return "size[8,9]" .. fs .. table_from_results(results, 0, 4, 8, 5, selected_def)
-end
-
-
-local function show_main(p_name, new_item, err_str, success)
-	minetest.show_formspec(p_name, main_form, mk_main_fs(p_name, new_item, err_str, success))
-end
-
-
 -- Something similar to creative inventory
 local pagemax = 1
+local pagewidth = 12
+local pageheight = 4
+local pageitems = pagewidth * pageheight
+local selectable_list = {}
 
--- Create detached inventory after loading all mods
+-- Create inventory list after loading all mods
 minetest.after(0, function()
-	local inv = minetest.create_detached_inventory("global_exchange", {
-		allow_move = function(inv, from_list, _, to_list, _,_, player)
-			local p_name = player:get_player_name()
-
-			if from_list == "main"
-			and to_list == "p_" .. p_name then
-				return 1
-			else
-				return 0
-			end
-		end,
-		allow_put = function()
-			return 0
-		end,
-		allow_take = function()
-			return 0
-		end,
-		on_move = function(inv, _, _, _, _, _, player)
-			local p_name = player:get_player_name()
-			local p_list = "p_" .. p_name
-
-			local item_name = inv:get_list(p_list)[1]:get_name()
-			inv:set_list(p_list, {})
-			inv:add_item("main", item_name)
-			show_main(p_name, item_name)
-		end,
-	})
-
-	local selectable_list,n = {},1
 	for name, def in pairs(minetest.registered_items) do
-		if (not def.groups.not_in_creative_inventory
-			or def.groups.not_in_creative_inventory == 0)
-		and def.description
-		and def.description ~= "" then
-			selectable_list[n] = name
-			n = n+1
+		if (def.groups.not_in_creative_inventory or 0) == 0 and
+		(split(def.description, "\n")[1] or "") ~= "" then
+			selectable_list[#selectable_list + 1] = name
 		end
 	end
 	table.sort(selectable_list)
-	inv:set_size("main", #selectable_list)
-	for _,itemstring in ipairs(selectable_list) do
-		inv:add_item("main", ItemStack(itemstring))
+
+	pagemax = math.max(math.ceil(#selectable_list / pageitems), 1)
+end)
+
+local main_form = "global_exchange:exchange_main"
+
+local function table_from_results(fs, results, name, x, y, w, h, selected)
+	fs:tablecolumns("text", "text", "text", "text", "text", "text", "text")
+	fs:table(x,y, w,h, name, function(add_row)
+		add_row("Poster", "Type", "Item",
+		        "Description",
+				"Wear", "Amount", "Rate")
+
+		local all_items = minetest.registered_items
+		for i, row in ipairs(results) do
+			local def = all_items[row.Item] or {}
+			add_row(row.Poster, row.Type, row.Item,
+			        split(def.description, "\n")[1] or "Unknown Item",
+					wear_string(row.Wear), row.Amount, row.Rate)
+		end
+	end, math.max(0, tonumber(selected) or 0) + 1)
+end
+
+local function mk_main_market_fs(fs, p_name, state)
+	fs(summary_fs)
+end
+
+local function mk_main_order_book_fs(fs, p_name, x, y, w, h, item_name)
+	local order_book = exchange:order_book("", item_name)
+
+	fs:tablecolumns("text", "text", "text", "text")
+	fs:table(x,y, w,h, "order_book", function(add_row)
+		add_row("Type", "Rate", "Wear", "Amount")
+		for _,row in ipairs(order_book) do
+			add_row(row.Type, row.Rate, wear_string(row.Wear), row.Amount)
+		end
+	end, 1)
+end
+
+local function mk_main_buy_fs(fs, p_name, state)
+	mk_main_order_book_fs(fs, p_name, 0, 0, 8.75, 3.75, state.buy_item)
+
+	fs:item_image_button(9,0, 1,1, "buy_item", state.buy_item)
+
+	fs:field(10.25,0.40, 2,1, "buy_amount", "Quantity", state.buy_amount, false)
+
+	local wear = wear_levels[state.buy_wear] or wear_levels[1]
+	fs:dropdown(9,1, 3, "buy_wear", function(add_item)
+		for _,v in ipairs(wear_levels) do
+			add_item(v.text)
+		end
+	end, wear.index)
+
+	fs:field(9.35,2.40, 2.9,1, "buy_price", "Bid (ea.)", state.buy_price, false)
+
+	fs:button(9,3, 3,1, "buy", "Place Bid")
+
+	fs:container(0,4, function()
+		fs:button( 0,0.25, 1,1, "buy_left",  "<<")
+		fs:button( 5,0.25, 2,1, "position",  state.buy_page .. "/" .. pagemax)
+		fs:button(11,0.25, 1,1, "buy_right", ">>")
+
+		local firstitem = ((state.buy_page - 1) * pageitems)
+		for y=0,(pageheight-1) do
+			for x=0,(pagewidth-1) do
+				local index = firstitem + (pagewidth * y) + x + 1
+				if selectable_list[index] then
+					fs:item_image_button(x,1.25+y, 1,1, "select_" .. index,
+						selectable_list[index])
+				end
+			end
+		end
+	end)
+end
+
+local function mk_main_sell_fs(fs, p_name, state)
+	local sell_stack = global_inv:get_stack("p_" .. p_name, 1)
+	local sell_item = (not sell_stack:is_empty()
+	                   and sell_stack:get_name()) or ""
+
+	mk_main_order_book_fs(fs, p_name, 0, 0, 8.75, 3.75, sell_item)
+
+	fs:list(9,0, 1,1, "detached:global_exchange", "p_" .. p_name)
+
+	fs:field(9.35,2.40, 2.9,1, "sell_price", "Ask (ea.)", state.sell_price, false)
+
+	fs:button(9,3, 3,1, "sell", "Sell")
+
+	fs:box(1.9375,5.1875, 7.96875,4.03, "#00000020")
+
+	fs:list(2,5.25, 8,4, "current_player", "main")
+end
+
+local function mk_main_own_orders_fs(fs, p_name, state)
+	if not state.own_results then
+		state.own_results = exchange:search_player_orders(p_name) or {}
 	end
 
-	pagemax = math.ceil((#selectable_list - 1) / (8 * 4))
-end)
+	state.selected_index = math.min(state.selected_index or 0, #state.own_results)
+
+	table_from_results(fs, state.own_results, "result_table", 0, 0, 11.75, 8.5, state.selected_index)
+	fs:button(4.5,8.5, 3,1, "cancel", "Cancel Order")
+end
+
+local main_tabs = {
+	[1] = { text = "Market",    mk_fs = mk_main_market_fs     },
+	[2] = { text = "Buy",       mk_fs = mk_main_buy_fs        },
+	[3] = { text = "Sell",      mk_fs = mk_main_sell_fs       },
+	[4] = { text = "My Orders", mk_fs = mk_main_own_orders_fs },
+}
+
+local function mk_main_fs(fs, p_name, err_str, success)
+	local state = main_state[p_name]
+	if not state then return end -- Should have been initialized on player join
+	
+	fs:size(12,10)
+	fs:bgcolor("#606060", false)
+
+	fs:tabheader(0,0.65, "tab", function(add_tab)
+		for _,tab in ipairs(main_tabs) do
+			add_tab(tab.text)
+		end
+	end, state.tab or 1, false, true)
+
+	local bal = exchange:get_balance(p_name)
+	fs:label(0,0.37, "Balance: " .. bal)
+
+	if err_str then
+		fs:label(4,0.37, err_str)
+	elseif success then
+		fs:label(4,0.37, "Success!")
+	end
+
+	if main_tabs[state.tab] then
+		fs:container(0,1, main_tabs[state.tab].mk_fs, p_name, state)
+	end
+end
+
+
+local function show_main(p_name, err_str, success)
+	local fs = formlib.Builder()
+	mk_main_fs(fs, p_name, err_str, success)
+	minetest.show_formspec(p_name, main_form, tostring(fs))
+end
 
 
 minetest.register_on_joinplayer(function(player)
-	-- the inventory list name is "p_"..player_name
-	minetest.get_inventory({
-		type="detached",
-		name="global_exchange"
-	}):set_size("p_" .. player:get_player_name(), 1)
+	-- the inventory list name (for selling) is "p_"..player_name
+	global_inv:set_size("p_"  .. player:get_player_name(), 1)
 end)
 
 
-local select_form = "global_exchange:select_form"
-
-
-local function mk_select_formspec(p_name, start_i, pagenum)
-	return "size[9.3,8]" ..
-		"list[detached:global_exchange;main;0.3,0.5;8,4;" .. tostring(start_i) .. "]" ..
-		"button[0.3,4.5;1.6,1;select_prev;<<]"..
-		"button[6.7,4.5;1.6,1;select_next;>>]"..
-		"label[2.0,5.55;"..tostring(math.floor(pagenum)).."/"..tostring(pagemax).."]"..
-		"list[detached:global_exchange;p_" .. p_name .. ";0.3,7;1,1;]"
-end
-
-
-local player_pages = {}
-
-
-local function show_select(p_name)
-	local pagenum = player_pages[p_name] or 1
-	local start_i = (pagenum - 1) * 8 * 4
-
-	local fs = mk_select_formspec(p_name, start_i, pagenum)
-	minetest.show_formspec(p_name, select_form, fs)
-end
-
-
-local own_form = "global_exchange:my_orders"
-
-local own_state = {}
--- ^ Per=player state for the own orders form. Contains these fields:
---     selected_index: The selected index
---     own_results: Results for own orders.
-
-local function mk_own_orders_fs(p_name, results, selected)
-	return "size[8,8]" ..
-		"label[0.5,0.2;Your Orders]" ..
-		"button[6,0;2,1;refresh;Refresh]" ..
-		table_from_results(results, 0, 2, 8, 4.5, selected or "") ..
-		"button[0,7;2,1;cancel;Cancel]" ..
-		"button[3,7;2,1;back;Back]"
-end
-
-
-local function show_own_orders(p_name, results, selected)
-	minetest.show_formspec(p_name, own_form, mk_own_orders_fs(p_name, results, selected))
-end
-
-
 -- Returns success, and also returns an error message if failed.
-local function post_order(player, ex_name, order_type, item_name, amount_str, rate_str)
+local function post_buy(player, ex_name, item_name, wear_str, amount_str, rate_str)
 	local p_name = player:get_player_name()
 
-	if item_name == "" then
+	if (item_name or "") == "" then
 		return false, "You must input an item"
-	end
-
-	if not minetest.registered_items[item_name] then
+	elseif not minetest.registered_items[item_name] then
 		return false, "That item does not exist."
 	end
 
+	local wear_level = wear_levels[wear_str]
+	if not wear_level then
+		return false, "Invalid wear."
+	end
+
 	local amount = tonumber(amount_str)
-	local rate = tonumber(rate_str)
+	local rate   = tonumber(rate_str)
 
-	if not amount then
+	if not amount or not is_integer(amount) or amount < 1 then
 		return false, "Invalid amount."
-	end
-
-	if not rate then
+	elseif not rate or not is_integer(rate) or rate < 1 then
 		return false, "Invalid rate."
 	end
 
-	if amount > 1000 then
-		return false, "Max amount is 1000"
-	end
-
 	local p_inv = player:get_inventory()
 	local stack = ItemStack(item_name)
-	stack:set_count(amount)
 
-	if order_type == "buy" then
-		if not p_inv:room_for_item("main", stack) then
-			return false, "Not enough space in inventory."
-		end
-
-		local succ, res = exchange:buy(p_name, ex_name, item_name, amount, rate)
-		if not succ then
-			return false, res
-		end
-
-		stack:set_count(res)
-		p_inv:add_item("main", stack)
-	else
-		if not p_inv:contains_item("main", stack) then
-			return false, "Items not in inventory."
-		end
-
-		local succ, res = exchange:sell(p_name, ex_name, item_name, amount, rate)
-		if not succ then
-			return false, res
-		end
-
-		p_inv:remove_item("main", stack)
+	local succ, res = exchange:buy(p_name, ex_name, item_name, wear_level.wear, amount, rate)
+	if not succ then
+		return false, res
 	end
 
+	for _,row in ipairs(res) do
+		stack:set_count(row.amount)
+		stack:set_wear(row.wear)
+
+		local leftover = p_inv:add_item("main", stack)
+
+		-- Put anything that won't fit in the inventory in the player's inbox
+		if not leftover:is_empty() then
+			exchange:put_in_inbox(p_name, item_name, row.wear, leftover:get_count())
+		end
+	end
+
+	-- Refresh market summary "soonish"
+	elapsed = math.max(elapsed, summary_interval - 5)
+
+	return true
+end
+
+-- Returns success, and also returns an error message if failed.
+-- The item to sell is determined by the player's list in global_inv.
+local function post_sell(player, ex_name, rate_str)
+	local p_name = player:get_player_name()
+	local stack  = global_inv:get_stack("p_" .. p_name, 1)
+
+	if not stack or stack:is_empty() then
+		return false, "You must input an item"
+	elseif not minetest.registered_items[stack:get_name()] then
+		return false, "That item does not exist."
+	end
+
+	if stack.get_meta then
+		local meta     = stack:get_meta()
+		local def_meta = ItemStack(stack:get_name()):get_meta()
+
+		if not stack:get_meta():equals(def_meta) then
+			return false, "Cannot sell an item with metadata."
+		end
+	elseif (stack:get_metadata() or "") ~= "" then
+		return false, "Cannot sell an item with metadata."
+	end
+
+	local rate = tonumber(rate_str)
+
+	if not rate or not is_integer(rate) or rate < 1 then
+		return false, "Invalid rate."
+	end
+
+	local item_name = stack:get_name()
+	local wear      = stack:get_wear()
+	local amount    = stack:get_count()
+
+	local succ, res = exchange:sell(p_name, ex_name, item_name, wear, amount, rate)
+	if not succ then
+		return false, res
+	end
+
+	stack:clear()
+	global_inv:set_stack("p_" .. p_name, 1, stack)
+
+	-- Refresh market summary "soonish"
+	elapsed = math.max(elapsed, summary_interval - 5)
+
 	return true
 end
 
@@ -339,185 +375,113 @@ end
 local function handle_main(player, fields)
 	local p_name = player:get_player_name()
 	local state = main_state[p_name]
-	local old_fields = state.old_fields
 
-	for k, v in pairs(fields) do
-		old_fields[k] = v
+	local copy_fields = {
+		"buy_wear",
+		"buy_amount",
+		"buy_price",
+		"sell_price"
+	}
+	for _,k in ipairs(copy_fields) do
+		if fields[k] then
+			state[k] = fields[k]
+		end
 	end
 
-	if fields.select_item then
-		show_select(p_name)
-	end
-
-	if fields.search then
-		local now = os.time()
-		local last_search = state.last_search_time
-
-		if now - last_search < search_cooldown then
-			show_main(p_name, nil, "Please wait before searching again.")
-			return
-		end
-
-		-- If the player is selling, she wants "buy" type offers.
-		local order_type
-		if state.sell then
-			order_type = "buy"
-		else
-			order_type = "sell"
-		end
-		local item_name = fields["item"]
-
-		local results = exchange:search_orders("", order_type, item_name)
-		state.search_results = results
-		state.last_search_time = now
-
+	if fields.tab then
+		state.tab = tonumber(fields.tab) or 1
 		show_main(p_name)
 	end
 
+	if fields.buy_left then
+		state.buy_page = (((state.buy_page or 1) + ((2*pagemax-1) - 1)) % pagemax) + 1
+		show_main(p_name)
+	end
+
+	if fields.buy_right then
+		state.buy_page = (((state.buy_page or 1) + ((2*pagemax-1) + 1)) % pagemax) + 1
+		show_main(p_name)
+	end
+
+	for name in pairs(fields) do
+		local index = tonumber(string.match(name, "select_([0-9]+)"))
+		if index and index >= 1 and index < #selectable_list then
+			state.buy_item = selectable_list[index]
+			show_main(p_name)
+		end
+	end
+
+	if fields.buy then
+		local succ, err =
+			post_buy(player, "", state.buy_item, fields.buy_wear,
+			         fields.buy_amount, fields.buy_price)
+		if succ then
+			state.buy_amount = "1"
+			state.buy_price = ""
+			state.own_results = nil
+			show_main(p_name, nil, true)
+		else
+			show_main(p_name, err)
+		end
+	end
+
 	if fields.sell then
-		state.sell = fields.sell == "true"
-	end
-
-
-	if fields.post_order then
-		local now = os.time()
-		local last_search = state.last_search_time
-
-		if now - last_search < search_cooldown then
-			show_main(p_name, nil, "Please wait before posting.")
-			return
-		end
-
-		local order_type
-		if state.sell then
-			order_type = "sell"
-		else
-			order_type = "buy"
-		end
-
-		local succ, err =
-			post_order(player, "", order_type, fields.item, fields.amount, fields.rate)
-
+		local succ, err = post_sell(player, "", fields.sell_price)
 		if succ then
-			state.search_results = {}
-			show_main(p_name, nil, nil, true)
+			state.sell_price = ""
+			state.own_results = nil
+			show_main(p_name, nil, true)
 		else
-			show_main(p_name, nil, err)
+			show_main(p_name, err)
 		end
 	end
 
-
-	if fields.result_table then
-		local results = state.search_results
-		local event = minetest.explode_table_event(fields.result_table)
-
-		if event.type ~= "CHG" then
-			return
-		end
-
-		local index = event.row - 1
-		result = results[index]
-
-		if result then
-			old_fields.amount = tostring(result.Amount)
-			old_fields.rate = tostring(result.Rate)
-		end
-
-		show_main(p_name)
-	end
-
-	if fields.summary then
-		show_summary(p_name)
-	end
-
-	if fields.your_orders then
-		if not own_state[p_name] then
-			own_state[p_name] = {}
-		end
-		local o_state = own_state[p_name]
-
-		o_state.own_results = exchange:search_player_orders(p_name) or {}
-
-		show_own_orders(p_name, o_state.own_results)
-	end
-end
-
-
-local function handle_select(player, fields)
-	local p_name = player:get_player_name()
-
-	local pagenum = player_pages[p_name] or 1
-
-	if fields.select_prev then
-		player_pages[p_name] = math.max(1, pagenum - 1)
-		show_select(p_name)
-	elseif fields.select_next then
-		player_pages[p_name] = math.min(pagemax, pagenum + 1)
-		show_select(p_name)
-	end
-end
-
-
-local function handle_own_orders(player, fields)
-	local p_name = player:get_player_name()
-
-	local state = own_state[p_name] or {}
-	local results = state.own_results or {}
 	local idx = state.selected_index
+	local own_results = state.own_results or {}
 
-	if fields.refresh then
-		state.own_results = exchange:search_player_orders(p_name) or {}
-		show_own_orders(p_name, state.own_results)
-	end
-
-	if fields.cancel and idx then
-		local row = results[idx]
-		if not row then return true end
-		local p_inv = player:get_inventory()
-
-		local amount = row.Amount
-		local item = row.Item
-		local stack = ItemStack(item)
-		stack:set_count(amount)
-		if row.Type == "sell" then
-			if not p_inv:room_for_item("main", stack) then
-				show_own_orders(p_name, state.own_results, "Not enough room.")
-				return true
-			end
-		end
-
-		local succ, err =
-			exchange:cancel_order(p_name, row.Id, row.Type, row.Item, row.Amount, row.Rate)
+	if fields.cancel and own_results[idx] then
+		local succ, res = exchange:cancel_order(p_name, own_results[idx].Id)
 		if succ then
-			table.remove(results, idx)
-			if row.Type == "sell" then
-				p_inv:add_item("main", stack)
+			if res.Type == "sell" then
+				local p_inv = player:get_inventory()
+				local stack = ItemStack(res.Item)
+				stack:set_count(res.Amount)
+				stack:set_wear(res.Wear)
+				local leftover = p_inv:add_item("main", stack)
+
+				-- Put anything that won't fit in the inventory in the player's inbox
+				if not leftover:is_empty() then
+					exchange:put_in_inbox(p_name, res.Item, res.Wear, leftover:get_count())
+				end
 			end
-		else
-			-- Refresh the results, since there might have been a problem.
-			state.own_results = exchange:search_player_orders(p_name) or {}
+
+			-- Refresh market summary "soonish"
+			elapsed = math.max(elapsed, summary_interval - 5)
 		end
 
-		show_own_orders(p_name, state.own_results)
+		state.own_results = nil
+		show_main(p_name)
 	end
 
 	if fields.result_table then
 		local event = minetest.explode_table_event(fields.result_table)
 		if event.type == "CHG" then
 			state.selected_index = event.row - 1
-			show_own_orders(p_name, results, event.row)
+			show_main(p_name)
 		end
 	end
 
-	if fields.back then
-		show_main(p_name)
-	end
-end
+	if fields.quit then
+		-- Return the player's unsold inventory, if any
+		local stack = global_inv:get_stack("p_" .. p_name, 1)
+		local p_inv = player:get_inventory()
+		local leftover = p_inv:add_item("main", stack)
 
+		-- Whatever doesn't fit in the player's inventory stays in the form.
+		-- Note that any items in the form when the server exits are lost.
+		global_inv:set_stack("p_" .. p_name, 1, leftover)
 
-local function handle_summary(player, fields)
-	if fields.back then
-		show_main(player:get_player_name())
+		state.own_results = nil
 	end
 end
 
@@ -525,12 +489,6 @@ end
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 	if formname == main_form then
 		handle_main(player, fields)
-	elseif formname == select_form then
-		handle_select(player, fields)
-	elseif formname == own_form then
-		handle_own_orders(player, fields)
-	elseif formname == summary_form then
-		handle_summary(player, fields)
 	else
 		return
 	end
@@ -538,6 +496,37 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 end)
 
 
+global_inv = minetest.create_detached_inventory("global_exchange", {
+	allow_move = function(inv,from_list,from_index,to_list,to_index,count,player)
+		return 0
+	end,
+	allow_put = function(inv,to_list,to_index,stack,player)
+		local p_name = player:get_player_name()
+
+		if to_list == "p_" .. p_name then
+			return stack:get_count()
+		else
+			return 0
+		end
+	end,
+	allow_take = function(inv,from_list,from_index,stack,player)
+		local p_name = player:get_player_name()
+
+		if from_list == "p_" .. p_name then
+			return stack:get_count()
+		else
+			return 0
+		end
+	end,
+	on_put = function(inv,to_list,to_index,stack,player)
+		show_main(player:get_player_name())
+	end,
+	on_take = function(inv,from_list,from_index,stack,player)
+		show_main(player:get_player_name())
+	end,
+})
+
+
 minetest.register_node("global_exchange:exchange", {
 	description = "Exchange Terminal",
 	drawtype = "nodebox",
@@ -552,18 +541,19 @@ minetest.register_node("global_exchange:exchange", {
 	paramtype = "light",
 	paramtype2 = "facedir",
 	groups = {cracky=2},
+	is_ground_content = false,
 	stack_max = 1,
 	light_source = 3,
 	node_box = {
 		type = "fixed",
 		fixed = {
-			{-8/16, -4/16, 3/16, 0.5, 0.5, 5/16},--screens
-			{-1/16, -7/16, 5/16, 1/16, 5/16, 7/16},--screen leg
-			{-3/16, -8/16, 4/16, 3/16, -7/16, 8/16},--leg platform
+			{-8/16, -4/16,  3/16, 8/16,  8/16,  5/16},--screens
+			{-1/16, -7/16,  5/16, 1/16,  5/16,  7/16},--screen leg
+			{-3/16, -8/16,  4/16, 3/16, -7/16,  8/16},--leg platform
 			{-7/16, -8/16, -8/16, 2/16, -6/16, -3/16},--keyboard
-			{3/16, -8/16, -3/16, 7/16, -7/16, 3/16},--phone low
-			{4/16, -7/16, -1/16, 6/16, -6/16, 3/16},--phone hi
-			{2/16, -7/16, 0, 8/16, -5/16, 2/16},--phone speaker
+			{ 3/16, -8/16, -3/16, 7/16, -7/16,  3/16},--phone low
+			{ 4/16, -7/16, -1/16, 6/16, -6/16,  3/16},--phone hi
+			{ 2/16, -7/16,  0/16, 8/16, -5/16,  2/16},--phone speaker
 		}
 	},
 	on_rightclick = function(_, _, clicker)
@@ -581,8 +571,9 @@ minetest.register_node("global_exchange:exchange", {
 minetest.register_craft( {
 	output = "global_exchange:exchange",
 	recipe = {
-		{ "default:steel_ingot", "default:steel_ingot", "default:steel_ingot" },
-		{ "default:mese_crystal", "default:steel_ingot", "default:diamond" },
-		{ "default:steel_ingot", "default:steel_ingot", "default:steel_ingot" },
+		{ "default:steel_ingot",  "default:steel_ingot", "default:steel_ingot" },
+		{ "default:mese_crystal", "default:steel_ingot", "default:diamond"     },
+		{ "default:steel_ingot",  "default:steel_ingot", "default:steel_ingot" },
 	}
 })
+-- vim:set ts=4 sw=4 noet:

formlib.lua

@@ -0,0 +1,172 @@
+local formlib = {}
+local builder_methods = {}
+
+function formlib.escape(x)
+	if x == nil then return "" end
+	return minetest.formspec_escape(tostring(x))
+end
+
+function formlib.bool(x)
+	-- nil and false are returned as-is, everything else maps to true
+	return x and true
+end
+
+function builder_methods.append(fs, ...)
+	for i=1,select("#", ...) do
+		local x = select(i, ...)
+		if x ~= nil then table.insert(fs, tostring(x)) end
+	end
+	return fs
+end
+
+function builder_methods.escape(fs, ...)
+	for i=1,select("#", ...) do
+		local x = select(i, ...)
+		if x ~= nil then table.insert(fs, formlib.escape(x)) end
+	end
+	return fs
+end
+
+function builder_methods.escape_list(fs, ...)
+	for i=1,select("#", ...) do
+		local x = select(i, ...)
+		if i > 1 then fs(",") end
+		fs:escape(x)
+	end
+	return fs
+end
+
+function builder_methods.escape_groups(fs, ...)
+	for i=1,select("#", ...) do
+		local group = select(i, ...)
+		if i > 1 then fs(";") end
+		if type(group) == "table" then
+			fs:escape_list(unpack(group))
+		else
+			fs:escape(group)
+		end
+	end
+	return fs
+end
+
+function builder_methods.element(fs, name, ...)
+	return fs(name, "["):escape_groups(...):append("]")
+end
+
+function builder_methods.size(fs, w,h, fixed)
+	if fixed == nil then
+		return fs:element("size", {w,h})
+	else
+		return fs:element("size", {w,h, formlib.bool(fixed)})
+	end
+end
+
+function builder_methods.bgcolor(fs, color, fullscreen)
+	if fullscreen == nil then
+		return fs:element("bgcolor", {color})
+	else
+		return fs:element("bgcolor", {color}, {formlib.bool(fullscreen)})
+	end
+end
+
+function builder_methods.list(fs, x,y, w,h, inv_loc, inv_list, start_idx)
+	return fs:element("list", {inv_loc}, {inv_list}, {x,y}, {w,h}, {start_idx})
+end
+
+function builder_methods.button(fs, x,y, w,h, name, text)
+	return fs:element("button", {x,y}, {w,h}, {name}, {text})
+end
+
+function builder_methods.item_image_button(fs, x,y, w,h, name, item, text)
+	return fs:element("item_image_button", {x,y}, {w,h}, {item}, {name}, {text})
+end
+
+function builder_methods.label(fs, x,y, text)
+	return fs:element("label", {x,y}, {text})
+end
+
+function builder_methods.field(fs, x,y, w,h, name, label, default, close_on_enter)
+	fs:element("field", {x,y}, {w,h}, {name}, {label}, {default})
+	if close_on_enter ~= nil then
+		fs:element("field_close_on_enter", {name}, {formlib.bool(close_on_enter)})
+	end
+	return fs
+end
+
+function builder_methods.box(fs, x,y, w,h, color)
+	return fs:element("box", {x,y}, {w,h}, {color})
+end
+
+function builder_methods.dropdown(fs, x,y, w, name, body_fn, selected_idx)
+	fs("dropdown["):escape_groups({x,y}, {w}, {name}):append(";")
+	local first = true
+	local results = { body_fn(function(...)
+		if first then first = false else fs(",") end
+		fs:escape(...)
+	end) }
+	if selected_idx ~= nil then fs(";"):escape(selected_idx) end
+	return fs("]"), unpack(results)
+end
+
+function builder_methods.tabheader(fs, x,y, name, body_fn, current_tab, transparent, draw_border)
+	fs("tabheader["):escape_groups({x,y}, {name}):append(";")
+	local first = true
+	local results = { body_fn(function(...)
+		if first then first = false else fs(",") end
+		fs:escape(...)
+	end) }
+	fs(";"):escape_groups({current_tab}, {formlib.bool(transparent)}, {formlib.bool(draw_border)})
+	return fs("]"), unpack(results)
+end
+
+function builder_methods.textlist(fs, x,y, w,h, name, body_fn, selected_idx, transparent)
+	fs("textlist["):escape_groups({x,y}, {w,h}, {name}):append(";")
+	local first = true
+	local results = { body_fn(function(...)
+		if first then first = false else fs(",") end
+		fs:escape(...)
+	end) }
+	fs(";"):escape_groups({selected_idx}, {formlib.bool(transparent)})
+	return fs("]"), unpack(results)
+end
+
+function builder_methods.tableoptions(fs, ...)
+	return fs:element("tableoptions", ...)
+end
+
+function builder_methods.tablecolumns(fs, ...)
+	return fs:element("tablecolumns", ...)
+end
+
+function builder_methods.table(fs, x,y, w,h, name, body_fn, selected_idx)
+	fs("table["):escape_groups({x,y}, {w,h}, {name}):append(";")
+	local first = true
+	local results = { body_fn(function(...)
+		if first then first = false else fs(",") end
+		fs:escape_list(...)
+	end) }
+	if selected_idx ~= nil then fs(";"):escape(selected_idx) end
+	return fs("]"), unpack(results)
+end
+
+function builder_methods.container(fs, x,y, sub_fn, ...)
+	fs:element("container", {x,y})
+	local results = { sub_fn(fs, ...) }
+	return fs("container_end[]"), unpack(results)
+end
+
+local builder_meta = {
+	__metatable = "protected",
+	__index = builder_methods,
+	__call = builder_methods.append,
+	__tostring = table.concat,
+}
+
+function formlib.Builder()
+	local fs = {}
+	setmetatable(fs, builder_meta)
+	return fs
+end
+
+return formlib
+-- vim:set ts=4 sw=4 noet:

init.lua

@@ -1,53 +1,45 @@
-
 local insecure_env = minetest.request_insecure_environment()
-assert(insecure_env,
-	"global_exchange needs to be trusted to run under mod security.")
+assert(insecure_env, "global_exchange needs to be trusted to run under mod security.")
 
 local modpath = minetest.get_modpath(minetest.get_current_modname()) .. "/"
 
-local income = tonumber(minetest.setting_get("citizens_income")) or 10
-local income_interval = 1200
-local income_msg = "You receive your citizen's income (+" .. income .. ")"
-
-local next_payout = os.time() + income_interval
-
-local exchange =
-        assert(loadfile(modpath .. "exchange.lua"))(insecure_env).open_exchange(
-		minetest.get_worldpath() .. "/global_exchange.db"
-)
+local exchange = assert(loadfile(modpath .. "exchange.lua"))(insecure_env).
+   open_exchange(minetest.get_worldpath() .. "/global_exchange.db")
 
+local formlib = assert(loadfile(modpath .. "formlib.lua"))()
 
 minetest.register_on_shutdown(function()
-	exchange:close()
+   exchange:close()
 end)
 
-
-local function check_giving()
-	local now = os.time()
-	if now < next_payout then
-		return
-	end
-
-	next_payout = now + income_interval
-
-	for _, player in ipairs(minetest.get_connected_players()) do
-		local p_name = player:get_player_name()
-
-		local succ = exchange:give_credits(p_name, income,
-			"Citizen's Income (+" .. income .. ")")
-
-		if succ then
-			minetest.chat_send_player(p_name, income_msg)
-		end
-	end
-
-	minetest.after(5, check_giving)
+local function handle_setbalance_command(caller, name, newbalance)
+   return exchange:set_balance(name, newbalance)
 end
 
-minetest.after(5, check_giving)
+minetest.register_privilege("balance", {
+   description = "Can use /setbalance",
+   give_to_singleplayer = false
+})
 
+minetest.register_chatcommand("setbalance", {
+   params      = "[<name>] <balance>",
+   description = "set a player's trading balance",
+   privs       = {balance=true},
+   func = function(caller, param)
+      local name, balancestr = string.match(param, "([^ ]+) ([0-9]+)")
+      if not name or not balancestr then
+         name = caller
+         balancestr = string.match(param, "([0-9]+)")
+         if not balancestr then
+            return false, "Invalid parameters (see /help setbalance)"
+         end
+      end
+      return handle_setbalance_command(caller, name, tonumber(balancestr))
+   end,
+})
 
+assert(loadfile(modpath .. "atm.lua"))(exchange, formlib)
+assert(loadfile(modpath .. "exchange_machine.lua"))(exchange, formlib)
+assert(loadfile(modpath .. "digital_mailbox.lua"))(exchange, formlib)
 
-assert(loadfile(modpath .. "atm.lua"))(exchange)
-assert(loadfile(modpath .. "exchange_machine.lua"))(exchange)
-assert(loadfile(modpath .. "digital_mailbox.lua"))(exchange)
+minetest.log("action", "[global_exchange] loaded.")