updated readme.md

includes description and code for a fully functional server with MongoDB integration

# Prerequisites

1.	installed npm: https://phoenixnap.com/kb/install-node-js-npm-on-windows

2.	Installed openapi generator with npm: https://openapi-generator.tech/docs/installation/

3.	Installed docker (if you want to use it): https://www.docker.com/get-started 

# Generate or update the server

In the following, we distinguish between a server code generation from scratch and an update of an existing solution

---

# First generation 

We provide a zip-file `additions.zip` with a folder structure and some files to simplify your work. 

If you want to use it unpack `additions.zip` in this folder and continue with the instruction for an [update](#update).

* server/data/ - empty folder for the databases of MongoDB 

* server/.openapi-generator-ignore - to prevent openapi-generator to override these files

## auto-generate server code

open a command shell and execute

```

**/Startup.cs

**/appsettings.json

**/Dockerfile

**/docker-compoese.yml

**/docker-compose.yml

**/.openapi-generator-ignore

**/ControllersImpl

## In Visual Studio:

open `NuGet Package Manager` and add `MongoDB.Driver`

### - folder `Controllers`: 

copy all files from `Controllers` to `ControllersImpl`

In all files in the folder `Controllers` change `public class` to `public abstract class`

### - folder `ControllersImpl`:

change classnames by appending `Impl` to the original classnames (and change filenames accordingly) and inherit from original class in `Controllers`

create a folder `ControllersImpl` and copy all files from `Controllers` to `ControllersImpl`

change classnames by appending `Impl` to the original classnames (and change filenames accordingly) and inherit from original class in `Controllers` (instead of `ControllerBase`) 

and replace `virtual` by `override` with all methods. 

```

remove sample code and replace it by using the appropriate methods of the corresponding classes in the folder `Services` 

(have a look into the above mentioned `additions.zip` for an example)

### - folder `Controllers`: 

In all files in the folder `Controllers` change `public class` to `public abstract class`

### - folder `Models`:

in the files add: 

```

### - folder `Services`

contains one class with the DatabaseSettings and one with the database-access-methods (create, get, update, remove) for each API

create the folder `Services` and have a look into the above mentioned `additions.zip` for an example

the folder `Services` should contain one class with the DatabaseSettings and one with the database-access-methods (create, get, update, remove) for each API

the naming in the DatabaseSettings is the same as defined in `appsettings.json `

and put MongoDB in folder `server/programs/MongoDB` (download MongoDB as zip-file from https://www.mongodb.com/try/download/community and unzip the file into this directory, so that the bin-directory is in this folder) 

---

# Update

```

## to start:

the easiest way is to use docker-compose:

if not already done (i.e. by using the above mentioned zip-file `additions.zip`):

* copy file `docker-compose.yml` and folder `docker` from the above mentioned zip-file `additions.zip` or

  * create a folder `docker` 

  * create a sub-folder `data-dump`

  * copy appsettings.json into the folder `docker` and adapt the connectionString for MongoDB for the usage in docker

  * create a file docker-compose.yml for the above created image and MongoDB-image or copy it from the above mentioned zip-file `additions.zip`

open a command shell and use docker-compose (if necessary adapt docker-compose.yml) by executing in `server/src/Org.OpenAPITools`:

```

  docker-compose up