Skip to content
This repository has been archived by the owner on Jan 8, 2021. It is now read-only.

PhysikOnline/elearning_new_backend

BranchesTags

Repository files navigation

Requirements

  • npm
  • node
  • nodemon (sudo npm install -g nodemon)
  • frontend

Recommendet Requirements

  • vscode (Extensions: Prettier)
  • MySQL Workbench
  • Postman

Packages we use

  • express-mysql-session
  • express-session
  • json2csv
  • multer
  • mysql
  • pdf-parse
  • compression
  • helmet
  • dotenv

Before you start

Make shure, that you created a .env file in your root directory, with the content:

# define development enviroment
NODE_ENV=development

# database connection
DB_HOST=141.2.246.162
DB_USER=elearning
DB_PORT=3306
DB_PASS=elearningpw
DB_DATA=elearning

if the database is realy busy, you can change the database name to your firstname.

Please do not commit the .env file. With this method, I want to prevent, that we are starting the development server on the live system, because this will remove all the data in the databse.

Database Tutorial

The connetion of the database is specified inside /db/db.js. The database initialisation script is located inside /db/init.sql. To use the Database in you .js files, you simplly do:

var sql = require("./db/db.js");

queries can the be executed with:

sql.query("you querry", function(error, results, fields) {
  if (error) throw error;
});

Documentation for MariaDB(SQL) and the MySQL Connector can be found here:

Start the Project

Before starting the project, you need to install all needed packages:

npm install

After a successfull install (Some package installs result in some warnings, but these can be connected, that you are not using a Mac) do:

npm run start

Session Tutorial

We use express-session (https://www.npmjs.com/package/express-session) to create an manage sessions. The client gets a sessionID. With that sessionID can be data associated (i.e. username) wich would normally be stored in the local storage of our server. I say normally, because we use the mysql extension of express-session (https://www.npmjs.com/package/express-mysql-session) wich allows us to store the data in our database, that enables us to use multiple servers for load balancing and persist sessions after server restarts. The session data (here username) can be accessed with:

req.session.username

I would recommend to read the documentation of express-session.

Error handling and validation

Validation

There is a Function to get the permissions of a user in a course. It is defined in ./src/courseFunctions.js. Basic usage is:

var permission = require("./courseFunctions");
permission(
  req.query.Semester,
  req.query.CourseName,
  req.session.username,
  function(perm) {
    if (perm === "admin") {
      /* have fun */
    } else {
      // respond, that the user has the wrong permissions
      next(new Error("wrong permissions or course not found"));
    }
  }
);

BUT THERE IS MORE!!!

Varriable validation is done by the database, which should return an error (can be mor or less easy to handle). For each api function, you PLEASE create a error handling script in ./apiFunctions/errorTranslation/, there are already more than enough examples. Then you insert your error translation into ./apiFunctions/errorTranslation.js. To use your error translation in your code, you can do:

var errorTranslation = require("../apiFunctions/errorTranslation");

// some code
sql.query("blablabla", [bla, blub, quark], function(error, results, fields) {
  if (error)
    return next(
      errorTranslation.theErrorFunctionThatYouWroteOutOfFreeWill(error)
    );
});
// other code

Error Handling

If you want to throw an error in your function to notify the api user, you can to

router.whatever("/pathsAreForNoobs", function(req, res, next) {
  return next(new Error("Your error!"));
});

API Documentation:

/user

POST /user/login

Attribute Type Required Describtion
username string yes Username you want to log in with
password string yes Password assiciated with the Username
Response Describtion
ERROR: User already logged in there is a user already logged in please log out before, or delete the session coockie
ERROR: Incorrect credentials the username or the passowrd provided, do not match the username or password stored in the database
Login successfull sucsesfully logged in, the username will be assiciated with the current session cockie

POST /user/logout

Attribute Type Required Describtion
- - - -
Response Describtion
successfully logged out the session was successfully removed
ERROR: No User logged in user not logged in, please log in

GET /user/checklogin

Attribute Type Required Describtion
- - - -
Response Describtion
true the session is assiciated with a logged in user
false there is no user belonging to this session

GET /course/allcourses

Attribute Type Required Describtion
- - - -

Response:
Getting an array of objects which are sorted by semester. The objects include names of courses for each semester.

Example

[
    {
        "Semester": "WiSe 19/20",
        "Name": [
            "Gewaltsamer Überfall für Fortgeschrittene",
            "Grundlagen in Mobbing 2",
            "Opferdarstellung 2"
        ]
    },
    {
        "Semester": "SoSe 19",
        "Name": [
            "Grundlagen in Mobbing 1",
            "Opferdarstellung 1",
            "Psychologie der erfolgreichen Erpressung 1"
        ]
    }
]

GET /course/coursecontent

Attribute Type Required Describtion
Semester string yes Semester of the course
Name string yes Module name of the course
Response Describtion
{ error: "No course found"} There is no with that Semester an Name

There is just one error response. An example response could be:

{
    "Semester": "WiSe 19/20",
    "Name": "Grundlagen in Mobbing 2",
    "auth": [
        "user",
        "admin"
    ]
}

For the authentication in the course we send an array of permissions. To verify it in the frontend you can do:

courseVarriable.auth.inculudes("admin");

POST /course/insertdescription

Attribute Type Required Describtion
Semester String yes Semester of the course
Name string yes Module name of the course
Description html(but it is not verified) yes The Description in HTML
Response Describtion
ERROR: No Course with Assigned User found The user has no permissions on the used course (not even the "user" permission)
Wrong permissions The user has not the "admin" permission
successfull The description was successfully changed

POST /course/group/joingroup

Attribute Type Required Describtion
Semester String yes Semester of the course
CourseName string yes Module name of the course
GroupName String yes Group Name of the Course
Response Describtion
{error: { User: "already in Group" }} User is already in a group
{error: { Group: "is Full" }} The group you want to join is full
{error: { Group: "can just be joined by course users" }} The logged in user is not a user of the course
{error: { Group: "not found" }} No group was found in the course
{error: { CourseName: "is too long" }} The CourseName is too Long
{error: { CourseName: "cannot be null" }} The CourseName cannot be null
{error: { Semester: "is too long" }} The Semester is too Long
{error: { Semester: "cannot be null" }} The Semester cannot be null
{error: { GroupName: "is too long" }} The GroupName is too Long
{error: { GroupName: "cannot be null" }} The GroupName cannot be null
{error: { User: "not logged in" }} There is no user logged in
successfull succsessfully joined the group

POST /course/group/leavegroup

Attribute Type Required Describtion
Semester String no Semester of the course
CourseName string no Module name of the course
GroupName String no Group Name of the Course
Response Describtion
{error: "User not in group or group not found or not logged in"} There is no User within such a Group or no user is logged in
successfull succsessfully left the group

POST /course/group/insertorupdategroup

        req.query.Room
Attribute Type Required Describtion
Semester String yes Semester of the course
CourseName string yes Module name of the course
GroupName String yes new Group Name of the Course (make it the same as OldGroupName to update the Group)
OldGroupName String yes Group Name of the Course (this will be the group name, if OldGroupName does not exist)
Tutor String no (Defaults to NULL) Tutor of the Group
Starttime String (HH:MM:SS 24h format) no (Defaults to CURRENT_TIMESTAMP) Starttime of the Tutorial
Endtime String (HH:MM:SS 24h format) no (Defaults to CURRENT_TIMESTAMP) Endtime of the Tutorial
Weekday String of ("Mo", "Di", "Mi", "Do", "Fr") no (Defaults to "Mo") The weekday of the Tutorial
MaxUser INT (Must be larer than the assigned users in the Group) no (Defaults to 15) Maximum number of user who can join the group
Room String (can be literally anything of 15 char or less lenght) no (Defaults to "") Room of the Group
Response Describtion
{error: { Weekday: "is too long"}} Weekday is too Long
{error: { Weekday: 'has to be "Mo", "Di", "Mi", "Do", "Fr"'}} Weekday is not one of the allowed values
{error: { Endtime: "wrong value"}} Endtime has a wrong format
{error: { Endtime: "out of boundaries"}} Endtime is not in the 24 h format
{error: { Starttime: "wrong value"}} Starttime has a wrong format
{error: { Starttime: "out of boundaries"}} Starttime is not in the 24 h format
{error: { GroupName: "already exists"}} GroupName you want to insert or update to already exists
{error: { GroupName: "must be defined"}} GroupName cannot be NULL
{error: { GroupName: "has wrong format"}} GroupName is not REGEX "^[ÄÖÜäöüßA-Za-z0-9 ]{3,20}$"
{error: { GroupName: "is too long"}} GroupName is too Long
{error: { Tutor: "login is too long"}} Tutor is too long
{error: { Tutor: "does not exist"}} Tutor user does not exist
{error: { MaxUser: "cannot be decreased"}} MaxUser cannot be decreased because other users may be in that group
{error: "wrong permissions or course not found"} The user has not the Admin permission on that course
successfull Group seccsessfully updated or inserted

POST /course/group/togglegroupvisibility

Attribute Type Required Describtion
Semester String yes Semester of the course
Name string yes Name of the course
Response Describtion
{error: {GroupVisible: "did not changed because GroupTimerActive was 1"}} GroupTimerActive is 1, either GroupVisibility or GroupTimerActive can be 1
{error: "wrong permissions or course not found"} The user has not the Admin permission on that course
successfull succsessfully toggled groupVisibility

POST /course/group/togglegrouptimeractive

Attribute Type Required Describtion
Semester String yes Semester of the course
Name string yes Name of the course
Response Describtion
{error: {GroupTimerActive: "did not changed because GroupVisibility was 1"}} GroupVisibility is 1, either GroupVisibility or GroupTimerActive can be 1
{error: "wrong permissions or course not found"} The user has not the Admin permission on that course
successfull succsessfully toggled groupTimerActive

POST /course/group/grouptimer

Attribute Type Required Describtion
Semester String yes Semester of the course
Name string yes Name of the course
Time string (MYSQL Datetime format) no (Defaults to CURRENT_TIMESTAMP) time where the group assigment starts
Response Describtion
{error: {GroupTimer: "has wrong date format"}} GroupTimer does not fullfill the MYSQL DATETIME format
{error: "wrong permissions or course not found"} The user has not the Admin permission on that course
successfull succsessfully toggled groupTimerActive

POST /course/group/groupcontent

Attribute Type Required Describtion
Semester String yes Semester of the course
Name string yes Name of the course
Response Describtion
successfull succsessfully toggled groupTimerActive

An example response can be

[
    {
        "GroupName": "Gruppe 1",
        "Tutor": "s0000002",
        "Ordering": 1,
        "Starttime": "15:27:07",
        "Endtime": "15:27:07",
        "Weekday": "Mo",
        "Maxuser": 15,
        "Room": ""
    },
    {
        "GroupName": "Gruppe 2",
        "Tutor": "s0000002",
        "Ordering": 2,
        "Starttime": "15:27:07",
        "Endtime": "15:27:07",
        "Weekday": "Mo",
        "Maxuser": 15,
        "Room": ""
    }
]

Todo

About

No description, website, or topics provided.

Resources

Readme
Activity
Custom properties

Stars

0 stars

Watchers

1 watching

Forks

0 forks
Report repository

Releases

No releases published

Packages

No packages published

Languages