Any way to guess the mime type on Delphi XE2?

Question

I need to guess the mime type with the purpose of fill the "Content-Type" header for some file uploads.

I fail to found a solution for it.

I wish to call something like: GetMimeType('C:File.jpg') and get back image/jpg.

Best if is multiplataform (for win/osx) but will be enough if only for windows.

Answer 1

Try using the FindMimeFromData Function.

FindMimeFromData contains hard-coded tests for (currently 26) separate MIME types (see Known MIME Types). This means that if a given buffer contains data in the format of one of these MIME types, a test exists in FindMimeFromData that is designed (by scanning through the buffer contents) to recognize the corresponding MIME type.

from urlmon.pas

function FindMimeFromData(
    pBC: IBindCtx;                      // bind context - can be nil
    pwzUrl: LPCWSTR;                    // url - can be nil
    pBuffer: Pointer;                   // buffer with data to sniff - can be nil (pwzUrl must be valid)
    cbSize: DWORD;                      // size of buffer
    pwzMimeProposed: LPCWSTR;           // proposed mime if - can be nil
    dwMimeFlags: DWORD;                 // will be defined
    out ppwzMimeOut: LPWSTR;            // the suggested mime
    dwReserved: DWORD                   // must be 0
  ): HResult; stdcall;

Also this article to see hot it works MIME Type Detection in Internet Explorer