Is there an enum for the ContentType property on a HttpWebResponse ("text/plain", "application/octet-stream" etc.)?

Question

The closest thing I could find was System.Net.Mime.MediaTypeNames but that doesn't seem to have everything (like json) since it seems to be more focused around email attachments.

Upcountry

Something similar here. People usually deal with it by creating constants as System.Net.Mime.MediaTypeNames would never be an exhaustive/complete list. – Impletion

Related post - What is the correct JSON content type? – Impletion

Answer 1

An enum doesn't make much sense. MIME types are open-ended. That is, the list is not finite: new types are added from time to time.

See RFC4288: Media Type Specifications and Registration Procedures

Allpowerful

It makes sense to me. Not as part of the .NET framework because that isn't updated frequently (nor should it be). But as a separate library that could be updated as frequently as new types are added (and users of the library cared). Time zones are open-ended too but that doesn't seem to obviate the utility of libraries based on tz database. – Mortarboard

@KennyEvitt We keep an internal enum for common types we use a lot. Nothing wrong with that. Seems better than magic strings, right? – Teutonize

Hindsight is 20/20 but MIME types, like HTTP status codes, whilst not finite, are a sensible use for constants or enums. As per my answer, in 2022, Microsoft include MIME type string constants. – Memo

Answer 2

In 2022, with .NET Core and .NET 5+, this is now available via MediaTypeNames. For example:

• MediaTypeNames.Application.Json
• MediaTypeNames.Image.Png
• MediaTypeNames.Text.Html

Microsoft documentation around MediaTypeNames, and each of Application, Image, Text.

• https://learn.microsoft.com/en-us/dotnet/api/system.net.mime.mediatypenames?view=net-6.0
• https://learn.microsoft.com/en-us/dotnet/api/system.net.mime.mediatypenames.application?view=net-6.0
• https://learn.microsoft.com/en-us/dotnet/api/system.net.mime.mediatypenames.image?view=net-6.0
• https://learn.microsoft.com/en-us/dotnet/api/system.net.mime.mediatypenames?view=net-6.0
• https://learn.microsoft.com/en-us/dotnet/api/system.net.mime.mediatypenames.text?view=net-6.0

Update 2013: Further MIME types have been added in .NET 8, and are much more exaustive: https://learn.microsoft.com/en-us/dotnet/api/system.net.mime.mediatypenames?view=net-8.0

Memo

Some of these mediatypenames also exist in .net 4.6, but important ones like application/json are missing – Wisecrack

This is good, but it looks like it is quite limited. I was looking for text/csv but it isn't supported. – Perky

@MichaelMurphy It appears support for text/csv has been added in .NET 8, alongside a bunch of others! learn.microsoft.com/en-us/dotnet/api/… – Memo

@richard_ob it's about time! – Perky

@Memo I think you mean Update 2023 (not 2013)! Also, thanks! – Changteh

Answer 3

IANA's database is most likely to be complete. Currently, they have the list available in CSV format at https://www.iana.org/assignments/media-types/application.csv. I am assuming this is a stable URL whose content changes as updates are made. If you want to stay up to date, you'd need to put together a mechanism that is appropriate for your needs.

There is also the mime.types file that comes with Apache which seems to have been derived from the said list.

Leiker

A flat list is already offered as CSV-file by the IANA's database website. – Dworman

I parsed the listed on Wikipedia some years ago and generated C#, its here: #10362640 – Calculate

Here a link to the IANA database with working .csv links: iana.org/assignments/media-types/media-types.xhtml – Chere

Answer 4

If like me you wanted to have no hard-coded string in your code you can use something like below

httpHeaders.add(HttpHeaders.CONTENT_TYPE,MediaType.APPLICATION_JSON_VALUE);

which is essentially httpHeaders.add("Content-Type","application/json");

Schaub

Answer 5

For my own limited purposes, I have made a static class that is basically a copy of the included .NET MediaTypeNames class but includes the MIME types I require; .NET MediaTypeNames is missing values I need.

public static class MediaMimeTypes
{
    /// <summary>
    /// Specifies that the MediaMimeType is not interpreted.
    /// </summary>
    public const string Octet = "application/octet-stream";

    /// <summary>
    /// Specifies that the MediaMimeType is in a Comma Separated Values (CSV) format.
    /// </summary>
    public const string Csv = "text/csv";
}

Perky