initialize

RSS/feeds.lua

@@ -0,0 +1,128 @@
+local FEEDS = {
+    feeds = {}
+}
+
+local FEEDS_PATH = "./feeds"
+local SLAXML = require('slaxml')
+local LOG = require('log')
+
+-- Retrieve feeds from config files and prepare them for use
+function FEEDS:Load()
+    self.feeds = {}
+
+    local files = fs.find(FEEDS_PATH .. "/*.json")
+    for _, v in ipairs(files) do
+        local file = fs.open(v, "r")
+        local contents = file.readAll()
+        local feed = textutils.unserialiseJSON(contents)
+
+        local response, err, _ = http.get(feed.link)
+        if response == nil then
+            LOG:Error("HTTP Error loading feed (" .. v .. "): " .. err)
+        else
+            local xml = response.readAll()
+            response.close()
+            local element
+            local in_item = false
+            local function startElement(name, nsURI, nsPrefix)
+                -- Track the current element name
+                element = name
+                if element == "item" then
+                    in_item = true
+                end
+            end
+            local function text(text, cdata)
+                -- Store the text content based on the current element name
+                if element == 'title' and not feed.title then
+                    feed.title = text
+                elseif in_item and not feed.last and element == 'guid' then
+                    feed.last = text
+                end
+            end
+            local parser = SLAXML:parser{
+                startElement = startElement,
+                text = text
+            }
+            parser:parse(xml)
+
+            if feed.title_override then
+                feed.title = feed.title_override
+            end
+
+            table.insert(self.feeds, feed)
+            LOG:Info("Loaded feed " .. feed.title)
+        end
+    end
+    if #self.feeds == 0 then
+        LOG:Info("No feeds loaded, nothing to do")
+        return true
+    end
+    return nil
+end
+
+function FEEDS:ParseLatest()
+    local output = {}
+    for _, feed in ipairs(self.feeds) do
+        local response, err, _ = http.get(feed.link)
+        if response == nil then
+            LOG:Error("HTTP Error fetching feed: " .. err)
+        else
+            local xml = response.readAll()
+            response.close()
+
+            local element
+            local new_last
+            local done = false
+            local current_item = {
+                colour = feed.colour,
+                source = feed.title
+            }
+            local in_item = false
+            local function startElement(name, nsURI, nsPrefix)
+                if done then return end
+
+                -- Track the current element name
+                element = name
+                if element == "item" then
+                    in_item = true
+                    current_item = {
+                        colour = feed.colour,
+                        source = feed.title
+                    }
+                end
+            end
+            local function closeElement(name, nsURI, nsPrefix)
+                if done then return end
+
+                if name == 'item' and not done then
+                    table.insert(output, current_item)
+                end
+            end
+            local function text(text, cdata)
+                if done or not in_item then return end
+
+                -- Store the text content based on the current element name
+                if element == 'title' then
+                    current_item.title = text
+                elseif in_item and element == 'guid' then
+                    if not new_last then
+                        new_last = text
+                    end
+                    if feed.last == text then
+                        done = true
+                    end
+                end
+            end
+            local parser = SLAXML:parser{
+                startElement = startElement,
+                closeElement = closeElement,
+                text = text
+            }
+            parser:parse(xml)
+            feed.last = new_last
+        end
+    end
+    return output
+end
+
+return FEEDS

RSS/feeds/nytimes.json

@@ -0,0 +1,5 @@
+{
+    "link": "https://rss.nytimes.com/services/xml/rss/nyt/Technology.xml",
+    "title_override": "NYT",
+    "colour": "9"
+}

RSS/feeds/tass.json

@@ -0,0 +1,5 @@
+{
+    "link": "https://tass.ru/rss/v2.xml",
+    "title_override": "TACC",
+    "colour": "b"
+}

RSS/feeds/youtube_generic.json

@@ -0,0 +1,5 @@
+{
+    "link": "https://www.youtube.com/@tag",
+    "title_override": "Youtuber name",
+    "colour": "e"
+}

RSS/graphics.lua

@@ -0,0 +1,71 @@
+local GRAPHICS = {
+    target = nil,
+    contents = {}
+}
+
+local LOG = require('log')
+
+-- Set target's colorscheme to gruvbox for better visuals
+function GRAPHICS:SetColours()
+    if self.target == nil then
+        return
+    end
+    self.target.setPaletteColour(colours.red, 0xfb4934)
+    self.target.setPaletteColour(colours.blue, 0x83a598)
+    self.target.setPaletteColour(colours.green, 0xb8bb26)
+    self.target.setPaletteColour(colours.purple, 0xd3869b)
+    self.target.setPaletteColour(colours.cyan, 0x8ec07c)
+    self.target.setPaletteColour(colours.white, 0xf9f5d7)
+    self.target.setPaletteColour(colours.black, 0x1d2021)
+end
+
+-- Set target output for our graphics
+function GRAPHICS:SetTarget(target)
+    self.target = target
+    if self.target == nil then
+        LOG:Error("Nil display target, items will not display")
+    end
+    target.clear()
+    target.setTextScale(0.5)
+    self:Refresh(true)
+end
+
+function GRAPHICS:Refresh(full)
+    if self.target == nil then
+        return
+    end
+    local _, y = self.target.getSize()
+    while #self.contents > y do
+        table.remove(self.contents, 1)
+    end
+
+    if full then
+        self.target.scroll(#self.contents)
+        for k, entry in ipairs(self.contents) do
+            self.target.setCursorPos(1, y - k + 1)
+            local output = "[" .. entry.source .. "] " .. entry.title
+            local fg_blit = "0" .. (entry.colour):rep(#entry.source) .. ("0"):rep(#entry.title + 2)
+            self.target.blit(output, fg_blit, ("f"):rep(#output))
+        end
+    else
+        self.target.scroll(1)
+        self.target.setCursorPos(1, y)
+        local entry = self.contents[#self.contents]
+        local output = "[" .. entry.source .. "] " .. entry.title
+        local fg_blit = "0" .. (entry.colour):rep(#entry.source) .. ("0"):rep(#entry.title + 2)
+        self.target.blit(output, fg_blit, ("f"):rep(#output))
+    end
+end
+
+function GRAPHICS:AddEntry(entry)
+    table.insert(self.contents, entry)
+    self:Refresh()
+end
+
+function GRAPHICS:Add(entries)
+    for _, entry in ipairs(entries) do
+        self:AddEntry(entry)
+    end
+end
+
+return GRAPHICS

RSS/log.lua

@@ -0,0 +1,98 @@
+local LOG = {
+    target = term,
+    history = {},
+    history_cutoff = 50,
+    log_path = "./logs/",
+    debug = false
+}
+
+-- Set target's colorscheme to gruvbox for better visuals
+function LOG:SetColours()
+    self.target.setPaletteColour(colours.red, 0xfb4934)
+    self.target.setPaletteColour(colours.blue, 0x83a598)
+    self.target.setPaletteColour(colours.green, 0xb8bb26)
+    self.target.setPaletteColour(colours.purple, 0xd3869b)
+    self.target.setPaletteColour(colours.cyan, 0x8ec07c)
+    self.target.setPaletteColour(colours.white, 0xf9f5d7)
+    self.target.setPaletteColour(colours.black, 0x1d2021)
+end
+
+-- Set target output for our log
+function LOG:SetTarget(target)
+    self.target = target
+    target.clear()
+    target.setTextScale(0.5)
+end
+
+function LOG:SetDebug(value)
+    self.debug = value
+end
+
+-- Utility function to output some kind of log message
+local function genericLog(log, level, message, col)
+    if #level ~= 4 or #col ~= 1 then
+        LOG:Error("Incorrect generic log format")
+        return
+    end
+
+    local target = log.target
+    target.scroll(1)
+    local _, y = target.getSize()
+    target.setCursorPos(1, y)
+
+    local time = os.date("%T", os.epoch("local") / 1000)
+    local output = "[" .. time .. "|" .. level .. "] " .. message
+    local fg_blit = ("0"):rep(#time + 2) .. (col):rep(4) .. ("0"):rep(#message + 2)
+    target.blit(output, fg_blit, ("f"):rep(#output))
+
+    table.insert(log.history, output)
+    if #log.history > log.history_cutoff then
+        table.remove(log.history, 1)
+    end
+end
+
+function LOG:Info(message)
+    genericLog(self, "INFO", message, "b")
+end
+
+function LOG:Success(message)
+    genericLog(self, "SCCS", message, "d")
+end
+
+function LOG:Debug(message)
+    if not self.debug then return end
+    genericLog(self, "DBUG", message, "8")
+end
+
+function LOG:Warning(message)
+    genericLog(self, "WARN", message, "4")
+end
+
+function LOG:Error(message)
+    genericLog(self, "ERRO", message, "e")
+end
+
+function LOG:Critical(message)
+    genericLog(self, "CRIT", message, "e")
+    self:Dump()
+    error("critical exception occured, read above")
+end
+
+function LOG:Clear()
+    self.history = {}
+end
+
+-- Put all recent log messages into a file for later study
+function LOG:Dump()
+    local out = ""
+    for _, v in ipairs(self.history) do
+        out = out + v .. "\n"
+    end
+    local time = os.date("%F-%T", os.epoch("local") / 1000)
+    local file = fs.open(string.format("%s/dump_%s.log", self.log_path, time), "w")
+    file.write(out)
+    file.close()
+    return out
+end
+
+return LOG

RSS/main.lua

@@ -0,0 +1,28 @@
+local LOG = require('log')
+local GRAPHICS = require('graphics')
+local FEEDS = require('feeds')
+
+local REFRESH_INTERVAL = 8
+local DEBUG = true
+local MONITOR = assert(peripheral.find('monitor'), "No monitor detected")
+
+local function main()
+    LOG:Info("RSS System init")
+    LOG:SetDebug(DEBUG)
+    LOG:SetTarget(term)
+    LOG:SetColours()
+    GRAPHICS:SetTarget(MONITOR)
+    GRAPHICS:SetColours()
+    local err = FEEDS:Load()
+    if err ~= nil then
+        return
+    end
+    LOG:Success("System fully loaded, beginning RSS processing")
+
+    while true do
+        GRAPHICS:Add(FEEDS:ParseLatest())
+        sleep(REFRESH_INTERVAL)
+    end
+end
+
+main()

RSS/slaxml.lua

@@ -0,0 +1,259 @@
+--[=====================================================================[
+v0.8 Copyright © 2013-2018 Gavin Kistner <!@phrogz.net>; MIT Licensed
+See http://github.com/Phrogz/SLAXML for details.
+--]=====================================================================]
+local SLAXML = {
+	VERSION = "0.8",
+	_call = {
+		pi = function(target,content)
+			print(string.format("<?%s %s?>",target,content))
+		end,
+		comment = function(content)
+			print(string.format("<!-- %s -->",content))
+		end,
+		startElement = function(name,nsURI,nsPrefix)
+			                 io.write("<")
+			if nsPrefix then io.write(nsPrefix,":") end
+			                 io.write(name)
+			if nsURI    then io.write(" (ns='",nsURI,"')") end
+			                 print(">")
+		end,
+		attribute = function(name,value,nsURI,nsPrefix)
+			                 io.write('  ')
+			if nsPrefix then io.write(nsPrefix,":") end
+			                 io.write(name,'=',string.format('%q',value))
+			if nsURI    then io.write(" (ns='",nsURI,"')") end
+			                 io.write("\n")
+		end,
+		text = function(text,cdata)
+			print(string.format("  %s: %q",cdata and 'cdata' or 'text',text))
+		end,
+		closeElement = function(name,nsURI,nsPrefix)
+			                 io.write("</")
+			if nsPrefix then io.write(nsPrefix,":") end
+			                 print(name..">")
+		end,
+	}
+}
+
+function SLAXML:parser(callbacks)
+	return { _call=callbacks or self._call, parse=SLAXML.parse }
+end
+
+function SLAXML:parse(xml,options)
+	if not options then options = { stripWhitespace=false } end
+
+	-- Cache references for maximum speed
+	local find, sub, gsub, char, push, pop, concat = string.find, string.sub, string.gsub, string.char, table.insert, table.remove, table.concat
+	local first, last, match1, match2, match3, pos2, nsURI
+	local unpack = unpack or table.unpack
+	local pos = 1
+	local state = "text"
+	local textStart = 1
+	local currentElement={}
+	local currentAttributes={}
+	local currentAttributeCt -- manually track length since the table is re-used
+	local nsStack = {}
+	local anyElement = false
+
+	local utf8markers = { {0x7FF,192}, {0xFFFF,224}, {0x1FFFFF,240} }
+	local function utf8(decimal) -- convert unicode code point to utf-8 encoded character string
+		if decimal<128 then return char(decimal) end
+		local charbytes = {}
+		for bytes,vals in ipairs(utf8markers) do
+			if decimal<=vals[1] then
+				for b=bytes+1,2,-1 do
+					local mod = decimal%64
+					decimal = (decimal-mod)/64
+					charbytes[b] = char(128+mod)
+				end
+				charbytes[1] = char(vals[2]+decimal)
+				return concat(charbytes)
+			end
+		end
+	end
+	local entityMap  = { ["lt"]="<", ["gt"]=">", ["amp"]="&", ["quot"]='"', ["apos"]="'" }
+	local entitySwap = function(orig,n,s) return entityMap[s] or n=="#" and utf8(tonumber('0'..s)) or orig end
+	local function unescape(str) return gsub( str, '(&(#?)([%d%a]+);)', entitySwap ) end
+
+	local function finishText()
+		if first>textStart and self._call.text then
+			local text = sub(xml,textStart,first-1)
+			if options.stripWhitespace then
+				text = gsub(text,'^%s+','')
+				text = gsub(text,'%s+$','')
+				if #text==0 then text=nil end
+			end
+			if text then self._call.text(unescape(text),false) end
+		end
+	end
+
+	local function findPI()
+		first, last, match1, match2 = find( xml, '^<%?([:%a_][:%w_.-]*) ?(.-)%?>', pos )
+		if first then
+			finishText()
+			if self._call.pi then self._call.pi(match1,match2) end
+			pos = last+1
+			textStart = pos
+			return true
+		end
+	end
+
+	local function findComment()
+		first, last, match1 = find( xml, '^<!%-%-(.-)%-%->', pos )
+		if first then
+			finishText()
+			if self._call.comment then self._call.comment(match1) end
+			pos = last+1
+			textStart = pos
+			return true
+		end
+	end
+
+	local function nsForPrefix(prefix)
+		if prefix=='xml' then return 'http://www.w3.org/XML/1998/namespace' end -- http://www.w3.org/TR/xml-names/#ns-decl
+		for i=#nsStack,1,-1 do if nsStack[i][prefix] then return nsStack[i][prefix] end end
+		error(("Cannot find namespace for prefix %s"):format(prefix))
+	end
+
+	local function startElement()
+		anyElement = true
+		first, last, match1 = find( xml, '^<([%a_][%w_.-]*)', pos )
+		if first then
+			currentElement[2] = nil -- reset the nsURI, since this table is re-used
+			currentElement[3] = nil -- reset the nsPrefix, since this table is re-used
+			finishText()
+			pos = last+1
+			first,last,match2 = find(xml, '^:([%a_][%w_.-]*)', pos )
+			if first then
+				currentElement[1] = match2
+				currentElement[3] = match1 -- Save the prefix for later resolution
+				match1 = match2
+				pos = last+1
+			else
+				currentElement[1] = match1
+				for i=#nsStack,1,-1 do if nsStack[i]['!'] then currentElement[2] = nsStack[i]['!']; break end end
+			end
+			currentAttributeCt = 0
+			push(nsStack,{})
+			return true
+		end
+	end
+
+	local function findAttribute()
+		first, last, match1 = find( xml, '^%s+([:%a_][:%w_.-]*)%s*=%s*', pos )
+		if first then
+			pos2 = last+1
+			first, last, match2 = find( xml, '^"([^<"]*)"', pos2 ) -- FIXME: disallow non-entity ampersands
+			if first then
+				pos = last+1
+				match2 = unescape(match2)
+			else
+				first, last, match2 = find( xml, "^'([^<']*)'", pos2 ) -- FIXME: disallow non-entity ampersands
+				if first then
+					pos = last+1
+					match2 = unescape(match2)
+				end
+			end
+		end
+		if match1 and match2 then
+			local currentAttribute = {match1,match2}
+			local prefix,name = string.match(match1,'^([^:]+):([^:]+)$')
+			if prefix then
+				if prefix=='xmlns' then
+					nsStack[#nsStack][name] = match2
+				else
+					currentAttribute[1] = name
+					currentAttribute[4] = prefix
+				end
+			else
+				if match1=='xmlns' then
+					nsStack[#nsStack]['!'] = match2
+					currentElement[2]      = match2
+				end
+			end
+			currentAttributeCt = currentAttributeCt + 1
+			currentAttributes[currentAttributeCt] = currentAttribute
+			return true
+		end
+	end
+
+	local function findCDATA()
+		first, last, match1 = find( xml, '^<!%[CDATA%[(.-)%]%]>', pos )
+		if first then
+			finishText()
+			if self._call.text then self._call.text(match1,true) end
+			pos = last+1
+			textStart = pos
+			return true
+		end
+	end
+
+	local function closeElement()
+		first, last, match1 = find( xml, '^%s*(/?)>', pos )
+		if first then
+			state = "text"
+			pos = last+1
+			textStart = pos
+
+			-- Resolve namespace prefixes AFTER all new/redefined prefixes have been parsed
+			if currentElement[3] then currentElement[2] = nsForPrefix(currentElement[3])    end
+			if self._call.startElement then self._call.startElement(unpack(currentElement)) end
+			if self._call.attribute then
+				for i=1,currentAttributeCt do
+					if currentAttributes[i][4] then currentAttributes[i][3] = nsForPrefix(currentAttributes[i][4]) end
+					self._call.attribute(unpack(currentAttributes[i]))
+				end
+			end
+
+			if match1=="/" then
+				pop(nsStack)
+				if self._call.closeElement then self._call.closeElement(unpack(currentElement)) end
+			end
+			return true
+		end
+	end
+
+	local function findElementClose()
+		first, last, match1, match2 = find( xml, '^</([%a_][%w_.-]*)%s*>', pos )
+		if first then
+			nsURI = nil
+			for i=#nsStack,1,-1 do if nsStack[i]['!'] then nsURI = nsStack[i]['!']; break end end
+		else
+			first, last, match2, match1 = find( xml, '^</([%a_][%w_.-]*):([%a_][%w_.-]*)%s*>', pos )
+			if first then nsURI = nsForPrefix(match2) end
+		end
+		if first then
+			finishText()
+			if self._call.closeElement then self._call.closeElement(match1,nsURI) end
+			pos = last+1
+			textStart = pos
+			pop(nsStack)
+			return true
+		end
+	end
+
+	while pos<#xml do
+		if state=="text" then
+			if not (findPI() or findComment() or findCDATA() or findElementClose()) then
+				if startElement() then
+					state = "attributes"
+				else
+					first, last = find( xml, '^[^<]+', pos )
+					pos = (first and last or pos) + 1
+				end
+			end
+		elseif state=="attributes" then
+			if not findAttribute() then
+				if not closeElement() then
+					error("Was in an element and couldn't find attributes or the close.")
+				end
+			end
+		end
+	end
+
+	if not anyElement then error("Parsing did not discover any elements") end
+	if #nsStack > 0 then error("Parsing ended with unclosed elements") end
+end
+
+return SLAXML

RSS/todo.txt

@@ -0,0 +1,3 @@
+* Add test file that checks entire system/functions before startup? or at least improve error checking
+* Enhance customisation per-feed e.g. define 14 colours and set which color each char in feed title is
+* Pre-Processing for russian language