TimeStamp Service: Exploring the wonderful World of Node.js

As part of the back end certification from Freecodecamp, I am making a timestamp service. Since, Freecodecamp is “under construction” I had to learn a lot of things myself.

I am using Webstorm on my mac Sirera with Node 6.9.1.

I have done the modules on Freecodecamp using learnyounode to learn the basics of node. One of the lessons on learnyounode was taking a time input and parsing it out into two json objects with natural and unix time objects respectively.

My first move was to create an http server using node.

var http = require('http');
var url = require('url');
var port = process.env.PORT || 3000;
var express = require('express');
var app = express();



var server = http.createServer(function (req,res) {
    
});

server.listen(Number(port));

Then, I tried to find out how to get the the argument from the url:

The time I am meant to parse will be given in in url in this form:

https://timestamp-ms.herokuapp.com/December%2015,%202015

So I ask Mr.Google and I stumbled upon this useful chart on how the requests are parsed when you use ulr.parse from node:

this image is from https://nodejs.org/docs/latest/api/url.html

Realizing that I need the pathname of the request, I checked it just to make sure.

var http = require('http');
var url = require('url');
var port = process.env.PORT || 3000;
var express = require('express');
var app = express();



var server = http.createServer(function (req,res) {
var data = url.parse(req.url,true);
var userinput = data['pathname'];
res.end(userinput['pathname'])
    
});

server.listen(Number(port));

It worked! Woooooooooooooot!

But my output was ugly.

/December%2015,%202015

I needed to clean it up. I split the string into an array, shift()-ed the ‘/’ off, and replaced “%20” with spaces.

This is the result:

December 15, 2015

This, I can put into my Date.parse() function and return a unix timestamp

var http = require('http');
var url = require('url');
var port = process.env.PORT || 3000;
var express = require('express');
var app = express();



var server = http.createServer(function (req,res) {
    var data = url.parse(req.url,true);
    re = /%20/g;
    var userinput = data['pathname'];
    userinput = userinput.replace(re," ");
    userinput = userinput.toString();
    userinput =userinput.split("");
    userinput.shift();
    userinput = userinput.join("");

    var date = new Date(userinput);
    var timestamp = Date.parse(userinput);
    var unixjs = {
        "unixtime": Math.floor(date.getTime())
    };
    res.end(timestamp.toString())
});

server.listen(Number(port), function () {
    console.log("app is listening on" +port)
});

n.b.: The timestamp variable will be a buffer so you must turn it into a string with the toString() function.

At this point, some of you might be thinking, “why doesn’t she just use express?”. Well…

I quickly turned the http.create server into an express server by installing express, requiring it, and creating an instance of it called app.

With the app instance, I exchanged the var server = http.createServer line with app.use and then replaced the server listener at the bottom with app.listen.

After this, I looked up a way to figure out if the input was a date. I used moments for this because it has a verify function that returns a boolean. This is great for if statements because I have to treat the input differently depending on the format.

var http = require('http');
var url = require('url');
var port = process.env.PORT || 3000;
var express = require('express');
var moment = require('moment');
var m = moment();
var app = express();
var path = '/Users/DragonQueen/WebstormProjects/timestampservice/';
app.use(function (req,res) {
    var data = url.parse(req.url,true);
    re = /%20/g;
    var userinput = data['pathname'];
    userinput = userinput.replace(re," ");
    userinput = userinput.toString();
    userinput =userinput.split("");
    userinput.shift();
    userinput = userinput.join("");
    if (userinput !== ""){
    var date = new Date(userinput);
    var output = {};
    if (moment.unix(userinput).isValid() == true){
        var unx =  moment.unix(userinput);
        output['unix'] = parseInt(userinput);
        output['natural'] = unx.format('MMMM Do YYYY');
    }
    else if (moment(userinput).isValid() == true){
        var unx = moment(date);
        output['unix'] = parseInt(date.getTime()/1000);
        output['natural'] = unx.format('MMMM Do YYYY');
    }
    else{
        output['unix'] = null;
        output['natural'] = null;
    }
    res.end(JSON.stringify(output))}

});

This worked wonderfully but I wanted a “home” screen so I created a pug (I have never used it and I wanted to experiment). For this, I had to create another app instance but this time it was an app.get. In that, I set the path for my pug template and just put in some simple text and the current date.

Then I had a second though about the pug. It worked but I felt a bit cocky. I made a simple HTML file that had the information about my app in markdown notation and used the Marked package to transform it. I also changed the font for it to look nicer but since the app is not very elaborate, I just went with simple text explanation (static file).

Now, I want to go ahead and deploy on Heroku.

All this time, I used Webstorm. Webstorm is great but using the built in terminal is annoying so I did all the terminal work in the terminal native to my mac.

I know NOTHING about Heroku so I went here. They have a tutorial for how to get started. I went through the tutorial and I still couldn’t quite get a clear picture in my head of what was happening so I went here. This is a node specific walk through. I went through all the steps on the page and fixed any problems as they arrive. I read the errors very carefully.

One thing to note with node is that you cannot use control z to kill the process. This will only suspend the process and that port will continue to be used by the program. You must use control c this will kill the program. If you are like me, and used to using z to terminate processes, you can go into your terminal and type in:

ps aux | grep node

and you will get a list that looks like this:

the first numbered column is called the process id number or the PID.

you can use the kill -9 tag followed by the PID to kill the process that is running on that port.

To kill my node index.js process, I needed to use:

kill -9 18515

That’s all! But it is a pain to do all the time.

While I was trying to actually deploy the app, I can into a problem. The

git push heroku master command was trying to push to a repo for a project I had deleted so I needed to remove that repo and put the new one as the master. I did that with the commands I found here. It is the answer by Gonzalo S.

I don’t know about the setup that others have, but even though I have root access on my mac, I have to use sudo every time the command has Heroku in it. I don’t know why.

This is what the home screen of my app looks like

What I learned:

1. use control c
2. the terminal is your friend
3. play with different packages butt…
4. try not to mess with the package.json directly

Then I just finished the step-by-step guide and put my app on Heroku. The finished app can be found here:

Marked in the browser

and the github repo can be found here:

Vworri/Backend-Dev-Work

I will be putting this on the portfolio on my website soon.

P.S:

While attempting to put another app on Heroku, I ran into a strange problem. It kept saying the repo I wanted either didn’t exist or that I did not have permission. So I did more research and found another Stackoverflow post that solved this problem. It is the answer by Joost Schuur. I took a screen shot:

hopefully, this can help someone down the line.