public/subjects/ascii-art-web/export-file/README.md

## ascii-art-web-export

### Objectives

You must follow the same [principles](../README.md) as the first subject.

Ascii-art-web-export consists on making sure that it is possible to export the output of the web application, at least in one export format at your choice.

- You should be able to export the result of the [ascii-art](../../ascii-art/README.md) project implemented in the website.
- The file must be exported with the right permissions (**read and write**) for the user.

The _Hypertext Transfer Protocol_ (HTTP) is the foundation of data communication for the World Wide Web (www). When sending a file or image as part of the HTTP response we must include the use of [HTTP headers](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers).

Headers used for file transfer are [Content-Type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type), [Content-Length](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Length) and [Content-Disposition](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition) and more if needed, but for this project you will be obligated to use those headers.

### Instructions

As you already learned from the previous project you must create a new HTTP endpoint to be able to transfer the file to the client. The following instructions must also be followed :

- The web server must export at least in one export format.
- The web server must be created in **Go**.
- The web site must include a button or a link to download/export the file.
- You must handle website errors.
- The code must respect the [good practices](../../good-practices/README.md).

### Allowed packages

- Only the [standard go](https://golang.org/pkg/) packages are allowed

This project will help you learn about :

- The basics of export formats :
  - Text File (txt)
  - [Here are some more examples](https://en.wikipedia.org/wiki/Document_file_format)
- [HTTP headers](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers)
- Ways to receive data.
- Ways to output data.