Red-out lines for recipes that require a rank we don't have yet

GnomishVendorShrinker.lua

@@ -240,6 +240,13 @@ local function Knowable(link)
 end
 
 
+local function RecipeNeedsRank(link)
+	local _, _, _, _, _, class = GetItemInfo(link)
+	if class ~= RECIPE then return end
+	return ns.unmet_requirements[link]
+end
+
+
 local default_grad = {0,1,0,0.75, 0,1,0,0} -- green
 local grads = setmetatable({
 	red = {1,0,0,0.75, 1,0,0,0},
@@ -273,6 +280,9 @@ local function ShowMerchantItem(row, i)
 			if ns.knowns[link] then
 				color = quality_colors[0]
 				row.backdrop:Hide()
+			elseif RecipeNeedsRank(link) then
+				row.backdrop:SetGradientAlpha("HORIZONTAL", unpack(grads.red))
+				row.backdrop:Show()
 			else
 				row.backdrop:SetGradientAlpha("HORIZONTAL", unpack(grads[quality]))
 				row.backdrop:Show()

KnownScanner.lua

@@ -26,3 +26,27 @@ ns.knowns = setmetatable({}, {
 		end
 	end
 })
+
+
+-- "Requires Previous Rank"
+local PREV_RANK = TOOLTIP_SUPERCEDING_SPELL_NOT_KNOWN
+local function NeedsRank(link)
+	ns.scantip:SetHyperlink(link)
+	for i=1,ns.scantip:NumLines() do
+		print(ns.scantip.L[i], ns.scantip.L[i] == PREV_RANK)
+		if ns.scantip.L[i] == PREV_RANK then return true end
+	end
+end
+
+
+ns.unmet_requirements = setmetatable({}, {
+	__index = function(t, i)
+		local id = ns.ids[i]
+		if not id then return end
+
+		if NeedsRank(i) then
+			t[i] = true
+			return true
+		end
+	end
+})