clouddemo2025.js (original) (raw)
const myVersion = "0.4.0", myProductName = "clouddemo";
const fs = require ("fs");
const utils = require ("daveutils");
const qs = require ("querystring");
const request = require ("request");
const davehttp = require ("davehttp");
const xml2js = require ("xml2js");
const reallysimple = require ("reallysimple");
// https://scott2.andysylvester.com/feed/ the feeds I used for my test
// https://rsscloud4.wordpress.com/feed/
var config = {
port: process.env.PORT || 2005, // was 1422, had tried 8080
flPostEnabled: true,
flLogToConsole: true, //davehttp logs each request to the console
flTraceOnError: false, //davehttp does not try to catch the error
defaultFeedUrl: "https://scott2.andysylvester.com/feed/", //4
thisServer: { //how the cloud server should call us back -- //1
domain: "john.mystatustool.com",
port: 80,
feedUpdatedCallback: "/feedupdated"
}
};
var whenLastRequest = new Date (0);
var stats = {
events: new Array () //2
}
var flStatsChanged = false;
const fnameStats = "stats.json";
function readStats (callback) {
fs.readFile (fnameStats, function (err, jsontext) {
try {
stats = JSON.parse (jsontext);
callback (undefined);
}
catch (err) {
callback (err);
}
});
}
function statsChanged () {
flStatsChanged = true;
}
function logEvent (infoAboutEvent) {
if (infoAboutEvent.whenstart !== undefined) {
infoAboutEvent.ctSecs = utils.secondsSince (infoAboutEvent.whenstart);
delete infoAboutEvent.whenstart;
}
infoAboutEvent.when = new Date ().toLocaleString ();
stats.events.push (infoAboutEvent); //insert at beginning
statsChanged ();
}
function requestWithRedirect (theRequest, callback) { //12/11/22 by DW
var myRequest = new Object ();
for (var x in theRequest) {
myRequest [x] = theRequest [x];
}
myRequest.followAllRedirects = false; //we're doing this ourselves
myRequest.maxRedirects = (myRequest.maxRedirects === undefined) ? 0 : myRequest.maxRedirects;
request (myRequest, function (err, response, body) {
const code = response.statusCode;
if ((code == 301) || (code == 302)) { //redirect
if (myRequest.maxRedirects == 0) {
callback (err, response, body);
}
else {
myRequest.maxRedirects--;
myRequest.url = response.headers.location;
requestWithRedirect (myRequest, callback);
}
}
else {
callback (err, response, body);
}
});
}
function getUrlCloudServer (theCloudElement) {
var url = undefined;
if ((theCloudElement !== undefined) && (theCloudElement.type == "rsscloud")) {
url = "http://" + theCloudElement.domain + ":" + theCloudElement.port + theCloudElement.path;
}
return (url);
}
function pleaseNotify (urlCloudServer, feedUrl, thisServer, callback) { //3
function buildParamList (paramtable) { //12/10/22 by DW
if (paramtable === undefined) {
return ("");
}
else {
var s = "";
for (var x in paramtable) {
if (paramtable [x] !== undefined) { //8/4/21 by DW
if (s.length > 0) {
s += "&";
}
s += x + "=" + encodeURIComponent (paramtable [x]);
}
}
return (s);
}
}
const theRequest = {
url: urlCloudServer,
method: "POST",
followAllRedirects: true,
maxRedirects: 5,
headers: {
"Content-Type": "application/x-www-form-urlencoded"
},
body: buildParamList ({
domain: thisServer.domain,
port: thisServer.port,
path: thisServer.feedUpdatedCallback,
url1: feedUrl,
protocol: "http-post"
})
};
requestWithRedirect (theRequest, function (err, response, body) {
if (err) {
callback (err);
}
else {
callback (undefined, body);
}
});
}
function requestNotification (feedUrl, callback) {
const whenstart = new Date ();
function getResponseFromXml (xmltext, callback) {
var options = {
explicitArray: false
};
xml2js.parseString (xmltext, options, function (err, jstruct) {
if (err) {
callback (err);
}
else {
if (jstruct == null) { //12/27/21 by DW
let err = {message: "Internal error: xml2js.parseString returned null."};
callback (err);
}
else {
callback (undefined, jstruct);
}
}
});
}
reallysimple.readFeed (feedUrl, function (err, theFeed) {
if (err) {
console.log (err.message);
if (callback !== undefined) {
callback (err);
}
}
else {
var urlCloudServer = getUrlCloudServer (theFeed.cloud);
pleaseNotify (urlCloudServer, feedUrl, config.thisServer, function (err, xmltext) {
if (err) {
console.log ("requestNotification: err.message == " + err.message + ", urlCloudServer == " + urlCloudServer + ", feedUrl == " + feedUrl);
logEvent ({
type: "requestNotification",
error: err.message,
urlCloudServer,
feedUrl,
whenstart
});
if (callback !== undefined) {
callback (err);
}
}
else {
getResponseFromXml (xmltext, function (err, jstruct) {
var theEvent = {
type: "requestNotification",
urlCloudServer,
response: jstruct.notifyResult ["$"],
feedUrl,
whenstart
}
logEvent (theEvent);
});
if (callback !== undefined) {
callback (undefined, theFeed);
}
}
});
}
});
}
function handlePing (feedUrl, callback) { //5
//12/17/22; 11:14:18 AM by DW
//this is where you'd put code that reads the feed, looks for new or updated items
//it's the punchline, why we did all this stuff in rssCloud, to get you this bit of info
//much faster.
callback (undefined, {status: "Got the update. Thanks! :-)"})
}
function handleHttpRequest (theRequest) {
var now = new Date ();
const params = theRequest.params;
function returnPlainText (theString) {
if (theString === undefined) {
theString = "";
}
theRequest.httpReturn (200, "text/plain", theString);
}
function returnNotFound () {
theRequest.httpReturn (404, "text/plain", "Not found.");
}
function returnError (jstruct) {
theRequest.httpReturn (500, "application/json", utils.jsonStringify (jstruct));
}
switch (theRequest.method) {
case "POST":
switch (theRequest.lowerpath) {
case config.thisServer.feedUpdatedCallback: //6
var jstruct = qs.parse (theRequest.postBody);
handlePing (jstruct.url, function (err, pingResponse) { //read the feed, add new stuff to database, etc.
returnPlainText (pingResponse.status);
logEvent ({
method: "POST",
path: config.thisServer.feedUpdatedCallback,
params: jstruct,
myResponse: pingResponse
});
});
break;
default:
returnNotFound ()
break;
}
break;
case "GET":
switch (theRequest.lowerpath) {
case "/now":
returnPlainText (new Date ());
return (true);
case config.thisServer.feedUpdatedCallback: //7
handlePing (params.url, function (err, pingResponse) { //read the feed, add new stuff to database, etc.
logEvent ({
method: "GET",
path: config.thisServer.feedUpdatedCallback,
params,
myResponse: params.challenge
});
returnPlainText (params.challenge);
});
break;
default:
returnNotFound ();
break;
}
break;
}
}
function everySecond () {
if (utils.secondsSince (whenLastRequest) > 3600) { //request notification once an hour
requestNotification (config.defaultFeedUrl);
whenLastRequest = new Date ();
}
if (flStatsChanged) {
flStatsChanged = false;
fs.writeFile (fnameStats, utils.jsonStringify (stats), function (err) {
if (err) {
console.log ("everySecond: err.message == " + err.message);
}
});
}
}
readStats (function (err) {
davehttp.start (config, handleHttpRequest);
setInterval (everySecond, 1000);
});