Mime Types

There are an infinite number of things we could consider "large files". But within the context of web development, the most common types of large files are probably:

1. Images: PNGs, JPEGs, GIFs, SVGs, etc.
2. Videos: MP4s, MOVs, AVIs, etc.
3. Audio: MP3s, WAVs, etc.
4. Static web templates: HTML, CSS, JS, etc.
5. Administrative files: PDFs, Word docs, etc.

A mime type is just a web-friendly way to describe format of a file. It's kind of like a file extension, but more standardized and built for the web.

Mime types have a type and a subtype, separated by a /. For example:

• image/png
• video/mp4
• audio/mp3
• text/html

When a browser uploads a file via a multipart form, it sends the file's mime type in the Content-Type header.

Assignment

Up until now we've allowed any file type to be uploaded as a thumbnail... let's fix that.

1. Use the mime.ParseMediaType function to get the media type from the Content-Type header
2. If the media type isn't either image/jpeg or image/png, respond with an error (respondWithError helper)
3. Try to upload the PDF file "is-bootdev-for-you.pdf" as a thumbnail - you should get an error

When you're done, answer the question.