Added event logging, improved error handling, added link caching

This commit is contained in:
benji7425 2016-10-31 23:28:17 +00:00
parent 1c782a2530
commit 5661af7b66
3 changed files with 77 additions and 46 deletions

View File

@ -1,5 +1,6 @@
{
"feedUrl": "https://www.youtube.com/feeds/videos.xml?user=EthosLab",
"channelID": "241238530376990722",
"pollingInterval": 5000
"pollingInterval": 5000,
"numLinksToCache": 10
}

View File

@ -1,10 +1,11 @@
var console = require("console");
var Dns = require("dns");
var Url = require("url");
var Discord = require("discord.io");
var FeedRead = require("feed-read");
var BotConfig = require("./botConfig.json");
var Config = require("./config.json");
var console = require("console"); //for console logging
var Dns = require("dns"); //for connectivity checking
var Url = require("url"); //for url parsing
var Uri = require("urijs"); //for finding urls within message strings
var Discord = require("discord.io"); //for obvious reasons
var FeedRead = require("feed-read"); //for rss feed reading
var BotConfig = require("./botConfig.json"); //bot config file containing bot token
var Config = require("./config.json"); //config file containing other settings
//get a URL object from the feedUrl so we can examine it and check connectivity later
var url = Url.parse(Config.feedUrl);
@ -12,9 +13,24 @@ var url = Url.parse(Config.feedUrl);
//placeholder for our bot - we need to check for connectivity before assigning this though
var bot;
var linkRegExp = new RegExp(["http", "https", "www"].join("|"));
var cachedLinks = [];
//caches a link so we can check again later
function cacheLink(link) {
//store the new link if not stored already
if (!cachedLinks.includes(link)){
cachedLinks.push(link);
logEvent("Cached URL: " + link);
}
//get rid of the first array element if we have reached our cache limit
if (cachedLinks.length > (Config.numLinksToCache || 10))
cachedLinks.shift();
}
//check if we can connect to discordapp.com to authenticate the bot
Dns.resolve("discordapp.com", function (err) {
if (err) console.log("CONNECTION ERROR: Unable to locate discordapp.com to authenticate the bot (you are probably not connected to the internet). Details: " + (err.message || err));
if (err) reportError("CONNECTION ERROR: Unable to locate discordapp.com to authenticate the bot (you are probably not connected to the internet). Details: " + (err.message || err));
else {
//if there was no error, go ahead and create and authenticate the bot
bot = new Discord.Client({
@ -24,18 +40,20 @@ Dns.resolve("discordapp.com", function (err) {
//when the bot is ready, set a polling interval for the rss feed
bot.on("ready", function () {
console.log(bot.username + " - (" + bot.id + ")");
logEvent(new Date().toLocaleString() + " Registered bot " + bot.username + " - (" + bot.id + ")");
//as we don't have any links cached, we need to check recent messages
checkPreviousMessagesForLinks();
logEvent("Setting up timer to check feed every " + Config.pollingInterval + " milliseconds");
setInterval(checkFeedAndPost, Config.pollingInterval);
});
//easy way to check if the bot is active - replies "pong" when you type "ping" in discord
bot.on("message", function (user, userID, channelID, message) {
if (message === "ping") {
bot.sendMessage({
to: channelID,
message: "pong"
});
//check if the message is a link, cache it if it is
if (new RegExp(linkRegExp.test(message))){
logEvent("Detected user posted link: " + message);
cacheLink(Uri.withinString(message, function (url) { return url; }));
}
});
}
@ -44,43 +62,54 @@ Dns.resolve("discordapp.com", function (err) {
function checkFeedAndPost() {
//check that we have an internet connection (well not exactly - check that we have a connection to the host of the feedUrl)
Dns.resolve(url.host, function (err) {
if (err) console.log("CONNECTION ERROR: Cannot resolve host (you are probably not connected to the internet). Details: " + (err.message || err));
else {
//check the feed asynchronously, check the latest link when done
FeedRead(Config.feedUrl, function (err, articles) {
try {
checkLinkAndPost(err, articles);
}
catch (ex) {
//checkFeedAndPost is async due to being called by setInterval so the console log has to be here
console.log("FEED ERROR: " + (ex.message || ex));
}
});
}
if (err) reportError("CONNECTION ERROR: Cannot resolve host (you are probably not connected to the internet). Details: " + (err.message || err));
else FeedRead(Config.feedUrl, checkLinkAndPost);
});
}
//checks if the link has been posted previously, posts if not
function checkLinkAndPost(err, articles) {
if (err) throw "Error reading RSS feed: " + (err.message || err);
var latestLink = articles[0].link;
//get the latest 100 messages (100 is the limit)
bot.getMessages({
channelID: Config.channelID,
limit: 100
}, function (err, messages) {
if (err) throw err;
//get an array of strings from the array of message objects
var messageContents = messages.map((message) => { return message.content; });
//if the messageContents array doesn't include the latest link, post it
if (!messageContents.includes(latestLink))
if (err) reportError("FEED ERROR: Error reading RSS feed. Details: " + (err.message || err));
else {
//get the latest link and check if it has already been posted and cached
var latestLink = articles[0].link;
if (!cachedLinks.includes(latestLink)) {
logEvent("Attempting to post new link: " + latestLink);
bot.sendMessage({
to: Config.channelID,
message: latestLink
});
cacheLink(latestLink);
}
}
}
//gets last 100 messages and extracts any links found (for use on startup)
function checkPreviousMessagesForLinks() {
var limit = 100;
logEvent("Attempting to check past " + limit + " messages for links");
bot.getMessages({
channelID: Config.channelID,
limit: limit
}, function (err, messages) {
if (err) reportError("Error fetching discord messages. Details: " + (err.message || err));
else {
logEvent("Pulled last " + messages.length + " messages, scanning for links");
var messageContents = messages.map((x) => { return x.content; });
for (var message in messageContents) {
message = messageContents[message];
if (linkRegExp.test(message))
cacheLink(Uri.withinString(message, function (url) { return url; }));
}
}
});
}
function logEvent(message){
console.log(new Date().toLocaleDateString() + " " + message);
}
//logs error to console with a timestamp
function reportError(message) {
console.log(new Date().toLocaleString() + " ERROR: " + message);
}

View File

@ -18,6 +18,7 @@
"homepage": "https://github.com/benji7425/discord-feed-bot#readme",
"dependencies": {
"discord.io": "^2.2.4",
"feed-read": "0.0.1"
"feed-read": "0.0.1",
"urijs": "^1.18.2"
}
}