Package for working with MIME type definitions and for processing streams of MIME multipart media types.
Determining the MIME type for a file
The MimeTypeResolver class can be used to determine the MIME type of
a file. It supports both using the extension of the file name and
looking at magic bytes from the beginning of the file.
There is a builtin instance of MimeTypeResolver accessible through
the top level function lookupMimeType. This builtin instance has
the most common file name extensions and magic bytes registered.
import 'package:mime/mime.dart';
void main() {
print(lookupMimeType('test.html'));
// text/html
print(lookupMimeType('test', headerBytes: [0xFF, 0xD8]));
// image/jpeg
print(lookupMimeType('test.html', headerBytes: [0xFF, 0xD8]));
// image/jpeg
}You can build you own resolver by creating an instance of
MimeTypeResolver and adding file name extensions and magic bytes
using addExtension and addMagicNumber.
Processing MIME multipart media types
The class MimeMultipartTransformer is used to process a Stream of
bytes encoded using a MIME multipart media types encoding. The
transformer provides a new Stream of MimeMultipart objects each of
which have the headers and the content of each part. The content of a
part is provided as a stream of bytes.
Below is an example showing how to process an HTTP request and print the length of the content of each part.
// HTTP request with content type multipart/form-data.
HttpRequest request = ...;
// Determine the boundary form the content type header
String boundary = request.headers.contentType.parameters['boundary'];
// Process the body just calculating the length of each part.
request
.transform(new MimeMultipartTransformer(boundary))
.map((part) => part.fold(0, (p, d) => p + d))
.listen((length) => print('Part with length $length'));