Update README with details of task 8

Author: samuelselasi

0x05-Node_JS_basic/README.md

@@ -373,3 +373,108 @@ Number of students in SWE: 4. List: Guillaume, Joseph, Paul, Tommy
 bob@dylan:~$
 ```
 
+[8. Organize a complex HTTP server using Express](./full_server)
+
+Obviously writing every part of a server within a single file is not sustainable. Let’s create a full server in a directory named `full_server`.
+
+Since you have used ES6 and Babel in the past projects, let’s use `babel-node` to allow to use ES6 functions like `import` or `export`.
+
+#### 8.1 Organize the structure of the server
+* Create `2` directories within:
+	* `controllers`
+	* `routes`
+* Create a file `full_server/utils.js`, in the file create a function named `readDatabase` that accepts a file path as argument:
+	* It should read the database asynchronously
+	* It should return a promise
+	* When the file is not accessible, it should reject the promise with the error
+	* When the file can be read, it should return an object of arrays of the firstname of students per fields
+
+#### 8.2 Write the App controller
+Inside the file `full_server/controllers/AppController.js`:
+
+* Create a class named `AppController`. Add a static method named `getHomepage`
+* The method accepts `request` and `response` as argument. It returns a `200` status and the message `Hello Holberton School!`
+
+#### 8.3 Write the Students controller
+Inside the file `full_server/controllers/StudentsController.js`, create a class named `StudentsController`. Add two static methods:
+
+The first one is `getAllStudents`:
+
+* The method accepts `request` and `response` as argument
+* It should return a status `200`
+* It calls the function `readDatabase` from the `utils` file, and display in the page:
+	* **First line**: `This is the list of our students`
+	* And for each field (*order by alphabetic order case insensitive*), a line that displays the number of students in the field, and the list of first names (*ordered by appearance in the database file*) with the following format: `Number of students in FIELD: 6. List: LIST_OF_FIRSTNAMES`
+* If the database is not available, it should return a status `500` and the error message `Cannot load the database`
+
+The second one is getAllStudentsByMajor:
+
+* The method accepts request and response as argument
+* It should return a status 200
+* It uses a parameter that the user can pass to the browser major. The major can only be CS or SWE. If the user is passing another parameter, the server should return a 500 and the error Major parameter must be CS or SWE
+* It calls the function readDatabase from the utils file, and display in the page the list of first names for the students (ordered by appearance in the database file) in the specified field List: LIST_OF_FIRSTNAMES_IN_THE_FIELD
+* If the database is not available, it should return a status 500 and the error message Cannot load the database
+
+#### 8.4 Write the routes
+Inside the file `full_server/routes/index.js`:
+
+* Link the route `/` to the `AppController`
+* Link the route `/students` and `/students/:major` to the `StudentsController`
+
+#### 8.5 Write the server reusing everything you created
+Inside the file named `full_server/server.js`, create a small `Express` server:
+
+* It should use the routes defined in `full_server/routes/index.js`
+*  It should use the port `1245`
+
+#### 8.6 Update `package.json` (if you are running it from outside the folder full_server)
+If you are starting node from outside of the folder `full_server`, you will have to update the command `dev` by: `nodemon --exec babel-node --presets babel-preset-env ./full_server/server.js ./database.csv`
+
+##### Warning:
+
+* Don’t forget to export your express app at the end of `server.js` (`export default app;`)
+* The database filename is passed as argument of the `server.js` BUT, for testing purpose, you should retrieve this filename at the execution (when `getAllStudents` or g`etAllStudentsByMajor` are called for example)
+
+**In terminal 1**:
+```
+bob@dylan:~$ npm run dev
+...
+```
+**In terminal 2**:
+```
+bob@dylan:~$ curl localhost:1245 && echo ""
+Hello Holberton School!
+bob@dylan:~$ 
+bob@dylan:~$ curl localhost:1245/students && echo ""
+This is the list of our students
+Number of students in CS: 6. List: Johann, Arielle, Jonathan, Emmanuel, Guillaume, Katie
+Number of students in SWE: 4. List: Guillaume, Joseph, Paul, Tommy
+bob@dylan:~$ 
+bob@dylan:~$ curl localhost:1245/students/SWE && echo ""
+List: Guillaume, Joseph, Paul, Tommy
+bob@dylan:~$ 
+bob@dylan:~$ curl localhost:1245/students/French -vvv && echo ""
+*   Trying 127.0.0.1...
+* TCP_NODELAY set
+* Connected to localhost (127.0.0.1) port 1245 (#0)
+> GET /students/SWES HTTP/1.1
+> Host: localhost:1245
+> User-Agent: curl/7.58.0
+> Accept: */*
+>
+< HTTP/1.1 500 Internal Server Error
+< X-Powered-By: Express
+< Date: Mon, 06 Jul 2020 03:29:00 GMT
+< Connection: keep-alive
+< Content-Length: 33
+<
+* Connection #0 to host localhost left intact
+Major parameter must be CS or SWE
+bob@dylan:~$
+```
+If you want to add test to validate your integration, you will need to add this file: `.babelrc`
+```
+{
+    "presets": [["env", {"exclude": ["transform-regenerator"]}]]
+}
+```