part 3 tweaks

Author: mluukkai

src/content/13/en/part13a.md

@@ -112,7 +112,7 @@ We can use the _heroku config_ command to get the <i>connect string</i>, which i
 ```bash
 heroku config -a <app-name>
 === cryptic-everglades-76708 Config Vars
-DATABASE_URL: postgres://<username>:<password>@<host-of-postgres-addon>:5432/<db-name>
+DATABASE_URL: postgres://<username>:thepasswordishere@<host-of-postgres-addon>:5432/<db-name>
 ```
 
 The database can be accessed by running _psql_ command on the Heroku server as follows (note that the command parameters depend on the connection url of the Heroku database):
@@ -317,7 +317,7 @@ If Heroku is used, the connect string can be seen by using the command _heroku c
 
 ```bash
 $ cat .env
-DATABASE_URL=postgres://<username>:<password>@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
+DATABASE_URL=postgres://<username>:thepasswordishere@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
 ```
 
 When using Fly.io, the local connection to the database should first be enabled by [tunneling](https://fly.io/docs/reference/postgres/#connecting-to-postgres-from-outside-fly) 
@@ -339,7 +339,7 @@ The Fly.io connect-string is of the form
 
 ```bash
 $ cat .env
-DATABASE_URL=postgres://postgres:<password>@127.0.0.1:5432/postgres
+DATABASE_URL=postgres://postgres:thepasswordishere@127.0.0.1:5432/postgres
 ```
 
 Password was shown when the database was created, so hopefully you have not lost it!

src/content/13/es/part13a.md

@@ -81,7 +81,7 @@ heroku create
 heroku addons:create heroku-postgresql:hobby-dev -a <app-name>
 heroku config -a <app-name>
 === cryptic-everglades-76708 Config Vars
-DATABASE_URL: postgres://<username>:<password>@<host-of-postgres-addon>:5432/<db-name>
+DATABASE_URL: postgres://<username>:thepasswordishere@<host-of-postgres-addon>:5432/<db-name>
 ```
 
 Particularmente cuando se utiliza una base de datos relacional, también es esencial acceder a la base de datos directamente. Hay muchas maneras de hacer esto, hay varias interfaces gráficas de usuario diferentes, como [pgAdmin](https://www.pgadmin.org/). Sin embargo, utilizaremos la herramienta de línea de comandos de Postgres [psql](https://www.postgresql.org/docs/current/app-psql.html).
@@ -236,7 +236,7 @@ La <i>cadena de conexión</i> de la base de datos, que es revelada por el comand
 
 ```bash
 $ cat .env
-DATABASE_URL=postgres://<username>:<password>@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
+DATABASE_URL=postgres://<username>:thepasswordishere@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
 ```
 
 Probemos una conexión exitosa:

src/content/13/fi/osa13a.md

@@ -108,7 +108,7 @@ heroku create
 heroku addons:create heroku-postgresql:hobby-dev
 heroku config
 === cryptic-everglades-76708 Config Vars
-DATABASE_URL: postgres://<username>:<password>@ec2-44-199-83-229.compute-1.amazonaws.com:5432/<db-name>
+DATABASE_URL: postgres://<username>:thepasswordishere@ec2-44-199-83-229.compute-1.amazonaws.com:5432/<db-name>
 ```
 
 Tietokantaan saadaan psql-konsoliyhteys suorittamalla _psql_ Herokun palvelimella seuraavasti (huomaa, että komennon parametrit riippuvat Heroku-sovelluksen connect urlista):
@@ -308,7 +308,7 @@ Herokua käyttäessäsi saat connect stringin selville komennolla _heroku config
 
 ```bash
 $ cat .env
-DATABASE_URL=postgres://<username>:<password>@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
+DATABASE_URL=postgres://<username>:thepasswordishere@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
 ```
 
 Fly.io:a käyttäessä paikallinen tietokantayhteys taytyy ensin tehdä mahdolliseksi [tunneloimalla](https://fly.io/docs/reference/postgres/#connecting-to-postgres-from-outside-fly) paikallisen koneen portti 5432 Fly.io:n tietokannan porttiin komennolla
@@ -329,7 +329,7 @@ Fly.io:n connect-string on seuraavaa muotoa:
 
 ```bash
 $ cat .env
-DATABASE_URL=postgres://postgres:<password>@localhost:5432/postgres
+DATABASE_URL=postgres://postgres:thepasswordishere@localhost:5432/postgres
 ```
 
 Salasana on se, jonka on otettu talteen tietokantaa luodessa.

src/content/13/zh/part13a.md

@@ -97,7 +97,7 @@ heroku create
 heroku addons:create heroku-postgresql:hobby-dev -a <app-name>
 heroku config -a <app-name>
 === cryptic-everglades-76708 Config Vars
-DATABASE_URL: postgres://<username>:<password>@<host-of-postgres-addon>:5432/<db-name>
+DATABASE_URL: postgres://<username>:thepasswordishere@<host-of-postgres-addon>:5432/<db-name>
 ```
 
 <!-- Particularly when using a relational database, it is essential to access the database directly as well. There are many ways to do this, there are several different graphical user interfaces, such as [pgAdmin](https://www.pgadmin.org/). However, we will be using Postgres [psql](https://www.postgresql.org/docs/current/app-psql.html) command-line tool.-->
@@ -262,7 +262,7 @@ The database <i>connect string</i>, which is revealed by the _heroku config_ com
 
 ```bash
 $ cat .env
-DATABASE_URL=postgres://<username>:<password>@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
+DATABASE_URL=postgres://<username>:thepasswordishere@ec2-54-83-137-206.compute-1.amazonaws.com:5432/<databasename>
 ```
 
 Let's test for a successful connection:

src/content/3/en/part3.md

@@ -8,7 +8,7 @@ lang: en
 
 In this part our focus shifts towards the backend, that is, towards implementing functionality on the server side of the stack. We will implement a simple REST API in Node.js by using the Express library, and the application's data will be stored in a MongoDB database. At the end of this part, we will deploy our application to the internet.
 
-<i>Part updated 14th August 2023</i>
-- <i>Create React App replaced with Vite</i>
+<i>Part updated 9th February 2024</i>
+- <i>No major changes</i>
 
 </div>

src/content/3/en/part3a.md

@@ -93,7 +93,7 @@ echo "Error: no test specified" && exit 1
 
 ### Simple web server
 
-Let's change the application into a web server by editing the _index.js_ file as follow:
+Let's change the application into a web server by editing the _index.js_ file as follows:
 
 ```js
 const http = require('http')
@@ -120,7 +120,7 @@ We can open our humble application in the browser by visiting the address <http:
 
 The server works the same way regardless of the latter part of the URL. Also the address <http://localhost:3001/foo/bar> will display the same content.
 
-**NB** if port 3001 is already in use by some other application, then starting the server will result in the following error message:
+**NB** If port 3001 is already in use by some other application, then starting the server will result in the following error message:
 
 ```bash
 ➜  hello npm start
@@ -138,7 +138,7 @@ Error: listen EADDRINUSE :::3001
     at listenInCluster (net.js:1378:12)
 ```
 
-You have two options. Either shut down the application using port 3001 (the json-server in the last part of the material was using port 3001), or use a different port for this application.
+You have two options. Either shut down the application using port 3001 (the JSON Server in the last part of the material was using port 3001), or use a different port for this application.
 
 Let's take a closer look at the first line of the code:
 
@@ -154,7 +154,7 @@ import http from 'http'
 
 These days, code that runs in the browser uses ES6 modules. Modules are defined with an [export](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/export) and taken into use with an [import](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import).
 
-However, Node.js uses so-called [CommonJS](https://en.wikipedia.org/wiki/CommonJS) modules. The reason for this is that the Node ecosystem needed modules long before JavaScript supported them in the language specification. Node supports now also the use of ES6 modules, but since the support is not quite perfect yet, we'll stick to CommonJS modules.
+Node.js uses by default so-called [CommonJS](https://en.wikipedia.org/wiki/CommonJS) modules. The reason for this is that the Node ecosystem needed modules long before JavaScript supported them in the language specification. Currently, Node supports also the use of ES6 modules, but since the support is not quite perfect yet, we'll stick to CommonJS modules.
 
 CommonJS modules function almost exactly like ES6 modules, at least as far as our needs in this course are concerned.
 
@@ -251,7 +251,7 @@ The source code for the dependency is installed in the <i>node\_modules</i> dire
 
 These are the dependencies of the express library and the dependencies of all of its dependencies, and so forth. These are called the [transitive dependencies](https://lexi-lambda.github.io/blog/2016/08/24/understanding-the-npm-dependency-model/) of our project.
 
-The version 4.18.2 of express was installed in our project. What does the caret in front of the version number in <i>package.json</i> mean?
+Version 4.18.2 of Express was installed in our project. What does the caret in front of the version number in <i>package.json</i> mean?
 
 ```json
 "express": "^4.18.2"
@@ -273,7 +273,7 @@ Likewise, if we start working on the project on another computer, we can install
 npm install
 ```
 
-If the <i>major</i> number of a dependency does not change, then the newer versions should be [backwards compatible](https://en.wikipedia.org/wiki/Backward_compatibility). This means that if our application happened to use version 4.99.175 of express in the future, then all the code implemented in this part would still have to work without making changes to the code. In contrast, the future 5.0.0 version of express [may contain](https://expressjs.com/en/guide/migrating-5.html) changes that would cause our application to no longer work.
+If the <i>major</i> number of a dependency does not change, then the newer versions should be [backwards compatible](https://en.wikipedia.org/wiki/Backward_compatibility). This means that if our application happened to use version 4.99.175 of Express in the future, then all the code implemented in this part would still have to work without making changes to the code. In contrast, the future 5.0.0 version of Express [may contain](https://expressjs.com/en/guide/migrating-5.html) changes that would cause our application to no longer work.
 
 ### Web and express
 
@@ -379,7 +379,7 @@ The contents of <i>package.json</i> have also changed:
     "express": "^4.18.2"
   },
   "devDependencies": {
-    "nodemon": "^2.0.20"
+    "nodemon": "^3.0.3"
   }
 }
 ```
@@ -603,8 +603,8 @@ Many tools exist for making the testing of backends easier. One of these is a co
 Let's install the Postman desktop client [from here](https://www.postman.com/downloads/)  and try it out:
 
 ![postman screenshot on api/notes/2](../../images/3/11x.png)
-NB: Postman is also available on VS Code which can be dowloaded from the Extension tab on the left -> search for Postman -> First result (Verified Publisher) -> Install
-You will then see an extra icon added on the activity bar below the extensions tab. Once you login, you can follow from the steps below 
+NB: Postman is also available on VS Code which can be downloaded from the Extension tab on the left -> search for Postman -> First result (Verified Publisher) -> Install
+You will then see an extra icon added on the activity bar below the extensions tab. Once you log in, you can follow the steps below 
 
 Using Postman is quite easy in this situation. It's enough to define the URL and then select the correct request type (DELETE).
 
@@ -672,9 +672,9 @@ The application prints the data that we sent in the request to the console:
 
 **NB** <i>Keep the terminal running the application visible at all times</i> when you are working on the backend. Thanks to Nodemon any changes we make to the code will restart the application. If you pay attention to the console, you will immediately be able to pick up on errors that occur in the application:
 
-![nodemon error as typing requre not defined](../../images/3/16.png)
+![nodemon error as typing requre not defined](../../images/3/16e.png)
 
-Similarly, it is useful to check the console for making sure that the backend behaves as we expect it to in different situations, like when we send data with an HTTP POST request. Naturally, it's a good idea to add lots of <em>console.log</em> commands to the code while the application is still being developed.
+Similarly, it is useful to check the console to make sure that the backend behaves as we expect it to in different situations, like when we send data with an HTTP POST request. Naturally, it's a good idea to add lots of <em>console.log</em> commands to the code while the application is still being developed.
 
 A potential cause for issues is an incorrectly set <i>Content-Type</i> header in requests. This can happen with Postman if the type of body is not defined correctly:
 

src/content/3/en/part3b.md

@@ -73,7 +73,7 @@ const cors = require('cors')
 app.use(cors())
 ```
 
-And the frontend works! However, the functionality for changing the importance of notes has not yet been implemented on the backend.
+Now most of the features in the frontend work! The functionality for changing the importance of notes has not yet been implemented on the backend so naturally that does not yet work in the frontend. We shall fix that later.
 
 You can read more about CORS from [Mozilla's page](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS).
 
@@ -85,19 +85,19 @@ The react app running in the browser now fetches the data from node/express-serv
 
 ### Application to the Internet
 
-Now that the whole stack is ready, let's move our application to the internet.
+Now that the whole stack is ready, let's move our application to Internet.
 
 There is an ever-growing number of services that can be used to host an app on the internet. The developer-friendly services like PaaS (i.e. Platform as a Service) take care of installing the execution environment (eg. Node.js) and could also provide various services such as databases.
 
 For a decade, [Heroku](http://heroku.com) was dominating the PaaS scene. Unfortunately the free tier Heroku ended at 27th November 2022. This is very unfortunate for many developers, especially students. Heroku is still very much a viable option if you are willing to spend some money. They also have [a student program](https://www.heroku.com/students) that provides some free credits.
 
-We are now introducing two services [Fly.io](https://fly.io/) and [Render](https://render.com/) that both have a (limited) free plan. Fly.io is our "official" hosting service since it can be for sure used also on the parts 11 and 13 of the course. Render will be fine at least for the other parts of this course.
+We are now introducing two services [Fly.io](https://fly.io/) and [Render](https://render.com/) that both have a (limited) free plan. Fly.io is our "official" hosting service since it can be for sure used also on parts 11 and 13 of the course. Render will be fine at least for the other parts of this course.
 
 Note that despite using the free tier only, Fly.io <i>might</i> require one to enter their credit card details. At the moment Render can be used without a credit card.
 
 Render might be a bit easier to use since it does not require any software to be installed on your machine.
 
-There are also some other free hosting options that work well for this course, at least for all parts other than part 11 (CI/CD) that might have one tricky exercise for other platforms.
+There are also some other free hosting options that work well for this course, at least for all parts other than part 11 (CI/CD) which might have one tricky exercise for other platforms.
 
 Some course participants have also used the following services:
 
@@ -163,7 +163,7 @@ Fly.io creates a file <i>fly.toml</i> in the root of your app where we can confi
   processes = ["app"]
 ```
 
-We have now defined in the part [env] that environment variable PORT will get the correct port (defined in part [http_service]) where the app should create the server. Note that the definition might be already there, but some times it has been missing.
+We have now defined in the part [env] that environment variable PORT will get the correct port (defined in part [http_service]) where the app should create the server. 
 
 We are now ready to deploy the app to the Fly.io servers. That is done with the following command:
 
@@ -174,12 +174,12 @@ fly deploy
 If all goes well, the app should now be up and running. You can open it in the browser with the command
 
 ```bash
-fly open
+fly apps open
 ```
 
 A particularly important command is _fly logs_. This command can be used to view server logs. It is best to keep logs always visible!
 
-**Note:** If you are using Fly.io, Fly may create 2 machines for your app, if it does then the state of the data in your app will be inconsistent between requests, i.e. you would have two machines each with its own notes variable, you could POST to one machine then your next GET could go to another machine. You can check the number of machines by using the command "$ fly scale show", if the COUNT is greater than 1 then you can enforce it to be 1 with the command "$ fly scale count 1". The machine count can also be checked on the dashboard.
+**Note:** Fly may create 2 machines for your app, if it does then the state of the data in your app will be inconsistent between requests, i.e. you would have two machines each with its own notes variable, you could POST to one machine then your next GET could go to another machine. You can check the number of machines by using the command "$ fly scale show", if the COUNT is greater than 1 then you can enforce it to be 1 with the command "$ fly scale count 1". The machine count can also be checked on the dashboard.
 
 **Note:** In some cases (the cause is so far unknown) running Fly.io commands especially on Windows WSL (Windows Subsystem for Linux) has caused problems. If the following command just hangs
 
@@ -252,7 +252,7 @@ app.listen(PORT, () => {
 
 So far we have been running React code in <i>development mode</i>. In development mode the application is configured to give clear error messages, immediately render code changes to the browser, and so on.
 
-When the application is deployed, we must create a [production build](https://vitejs.dev/guide/build.html) or a version of the application which is optimized for production.
+When the application is deployed, we must create a [production build](https://vitejs.dev/guide/build.html) or a version of the application that is optimized for production.
 
 A production build for applications created with Vite can be created with the command [npm run build](https://vitejs.dev/guide/build.html).
 
@@ -363,11 +363,11 @@ fly deploy
 
 The application works perfectly, except we haven't added the functionality for changing the importance of a note to the backend yet.
 
-<i>**NOTE:** If you are using Fly.io, there could be a .dockerignore file that specifies the exclusion of the "./build" directory during deployment. To ensure it gets deployed, consider renaming the ./build directory to ./static_build or an equivalent name.</i>
+<strong>NOTE:</strong> When using Fly.io, be aware that the _.dockerignore_ file in your project directory lists files not uploaded during deployment. The dist directory is included by default. To deploy this directory, remove its reference from the .dockerignore file, ensuring your app is get properly deployed.
 
 ![screenshot of notes application](../../images/3/30new.png)
 
-<i>**NOTE:** changing of the importance DOES NOT work yet since the backend has no implementation for it yet.</i>
+<i>**NOTE:** changing the importance DOES NOT work yet since the backend has no implementation for it yet.</i>
 
 Our application saves the notes to a variable. If the application crashes or is restarted, all of the data will disappear.