README
U
Callback
E
MultipartError
- ::FormForm::Form
- ::next_partForm::next_part
- ::content_typeFormPart::content_type
- ::filenameFormPart::filename
- ::headersFormPart::headers
- ::nameFormPart::name
- ::FormWriterFormWriter::FormWriter
- ::boundaryFormWriter::boundary
- ::content_typeFormWriter::content_type
- ::finishFormWriter::finish
- ::write_fieldFormWriter::write_field
- ::write_fileFormWriter::write_file
- ::write_jsonFormWriter::write_json
- ::write_partFormWriter::write_part
- ::ReaderReader::Reader
- ::next_partReader::next_part
- ::WriterWriter::Writer
- ::finishWriter::finish
- ::write_partWriter::write_part
- ::write_readerWriter::write_reader
V
parse_header_value

multipart

A streaming multipart reader/writer library integrated with `moonbitlang/async`.

multipart

form-data

Download zip

Author

Yoorkin

Version

0.2.2

License

Apache-2.0

Repository

github.com/Yoorkin/multipart

Last updated

14 days ago

Downloads

11K

moonbitlang/async0.22.1

#multipart

A streaming multipart reader/writer library integrated with moonbitlang/async.

Reader/Writer handle MIME multipart, Form/FormWriter handle multipart/form-data. Part bodies are streamed as raw bytes.

#Examples

Upload a field and a file through an HTTP client:

///|
async fn upload(client : @http.Client, file : &@io.Reader) -> @http.Response {
  let form = @multipart.FormWriter(client)
  client.request(Post, "/upload", extra_headers={
    "Content-Type": form.content_type(),
  })
  form.write_field("description", "Release archive")
  form.write_file("archive", filename="release.zip", file)
  form.finish()
  client.end_request()
}

Read an upload using the request's Content-Type and copy its archive part:

///|
async fn receive_archive(
  source : &@io.Reader,
  target : &@io.Writer,
  content_type : String,
) -> Unit {
  let (media_type, parameters) = @multipart.parse_header_value(content_type)
  guard @http.CaseInsensitiveString(media_type) == "multipart/form-data" else {
    raise Failure("expected multipart/form-data")
  }
  guard parameters.get("boundary") is Some(boundary) else {
    raise Failure("missing multipart boundary")
  }
  let form = @multipart.Form(source, boundary~)
  while form.next_part() is Some(part) {
    if part.name() == "archive" {
      target.write_reader(part)
    }
  }
}

next_part() discards unread content from the previous part. Process parts sequentially; finish() leaves the underlying writer open.

For other multipart subtypes, use Reader/Writer with your own headers:

///|
async fn copy_parts(source : &@io.Reader, target : &@io.Writer) -> Unit {
  let reader = @multipart.Reader(source, boundary="incoming")
  let writer = @multipart.Writer(target, boundary="outgoing")
  while reader.next_part() is Some((headers, body)) {
    writer.write_reader(headers~, body)
  }
  writer.finish()
}

Choose an output boundary that does not occur in the content. FormWriter creates a random boundary automatically.

#Tests

See fixtures for specification sources and snapshot tests.

Callback

source

type Callback = async (&@moonbitlang/async/io.Writer
Writer) -> Unit

MultipartError

source

pub suberror MultipartError {
  MultipartError(String)
} derive(@moonbitlang/core/debug.Debug
Debug)

Form

source

type Form

Streams the parts of a multipart/form-data body in their original order.

Form::Form

source

fn Form::Form(source : &@moonbitlang/async/io.Reader
Reader, boundary~ : String) -> Form raise MultipartError

Form::next_part

source

async fn Form::next_part(self : Form) -> FormPart?

Advancing discards any unread bytes from the previous part. Bodies remain bytes: charset and Content-Transfer-Encoding are not decoded. Nested multipart bodies are exposed as parts and can be traversed with Reader.

FormPart

source

type FormPart

impl Reader for FormPart

async fn _direct_read(self : FormPart, buffer : FixedArray[Byte], offset~ : Int, max_len~ : Int) -> Int

source

fn _get_internal_buffer(self : FormPart) -> @moonbitlang/async/io.ReaderBuffer
ReaderBuffer

source

FormPart::content_type

source

fn FormPart::content_type(self : FormPart) -> String

Returns the full Content-Type value, including any charset parameter. RFC 7578 §4.4 specifies text/plain when the header is absent.

FormPart::filename

source

fn FormPart::filename(self : FormPart) -> String?

Returns the supplied filename. When saving a file, the caller must discard directory components and choose a suitable local name (RFC 7578 §4.2). Percent escapes remain literal because multipart/form-data does not identify whether a filename uses the optional percent-encoding convention.

FormPart::headers

source

fn FormPart::headers(self : FormPart) -> Map[@moonbitlang/async/http.CaseInsensitiveString
CaseInsensitiveString, String]

FormPart::name

source

fn FormPart::name(self : FormPart) -> String

FormWriter

source

type FormWriter

FormWriter::FormWriter

source

fn FormWriter::FormWriter(target : &@moonbitlang/async/io.Writer
Writer, boundary? : String) -> FormWriter raise MultipartError

Create a form writer. The boundary defaults to 192 bits of platform entropy, so that it cannot occur in the part bodies (RFC 2046 section 5.1.1). Pass one explicitly when the platform cannot provide secure randomness, or when the wire bytes must be reproducible; in that case it is the caller's responsibility that no part body contains it.

FormWriter::boundary

source

fn FormWriter::boundary(self : FormWriter) -> String

The generated boundary, for constructing a matching reader or MIME header.

FormWriter::content_type

source

fn FormWriter::content_type(self : FormWriter) -> String

The HTTP Content-Type for the generated form body.

FormWriter::finish

source

async fn FormWriter::finish(self : FormWriter) -> Unit

FormWriter::write_field

source

async fn FormWriter::write_field(self : FormWriter, name : String, value : String) -> Unit

Write a UTF-8 text field, preserving the value's line endings.

FormWriter::write_file

source

async fn FormWriter::write_file(self : FormWriter, name : String, filename? : String, content_type? : String, file : &@moonbitlang/async/io.Reader
Reader) -> Unit

Stream a file without closing its reader. An unspecified content type uses application/octet-stream; filename is optional (RFC 7578 sections 4.2–4.4).

FormWriter::write_json

source

async fn FormWriter::write_json(self : FormWriter, name : String, value : Json) -> Unit

Write a JSON field with Content-Type application/json.

FormWriter::write_part

source

async fn FormWriter::write_part(self : FormWriter, headers~ : Map[@moonbitlang/async/http.CaseInsensitiveString
CaseInsensitiveString, String], callback : async (&@moonbitlang/async/io.Writer
Writer) -> Unit) -> Unit

Write a part with caller-supplied MIME headers.

Reader

source

type Reader

A sequential, streaming MIME multipart reader (RFC 2046 section 5.1.1). The source must be limited to the enclosing message body.

Reader::Reader

source

fn Reader::Reader(source : &@moonbitlang/async/io.Reader
Reader, boundary~ : String) -> Reader raise MultipartError

boundary is the decoded Content-Type parameter, without quotes or --.

Reader::next_part

source

async fn Reader::next_part(self : Reader) -> (Map[@moonbitlang/async/http.CaseInsensitiveString
CaseInsensitiveString, String], &@moonbitlang/async/io.Reader
Reader)?

Read the next part's headers and a reader limited to its body. Advancing drains the previous part; retained readers then return EOF. Preamble and epilogue are ignored. Bodies are returned without transfer decoding. Header folding is unfolded; repeated names are comma-joined as in @http.Headers. Calls on this reader and its current part must be made sequentially.

Writer

source

type Writer

Writer::Writer

source

fn Writer::Writer(target : &@moonbitlang/async/io.Writer
Writer, boundary~ : String) -> Writer raise MultipartError

Create a multipart writer. The caller must choose a boundary that does not occur as a delimiter in any part (RFC 2046 section 5.1.1).

Writer::finish

source

async fn Writer::finish(self : Writer) -> Unit

Write the closing delimiter without closing the underlying writer. Repeated calls have no effect.

Writer::write_part

source

async fn Writer::write_part(self : Writer, headers~ : Map[@moonbitlang/async/http.CaseInsensitiveString
CaseInsensitiveString, String], callback : async (&@moonbitlang/async/io.Writer
Writer) -> Unit) -> Unit

Write a part without buffering its body. Call parts sequentially, and use the callback's writer only until the callback returns.

Writer::write_reader

source

async fn Writer::write_reader(self : Writer, headers~ : Map[@moonbitlang/async/http.CaseInsensitiveString
CaseInsensitiveString, String], source : &@moonbitlang/async/io.Reader
Reader) -> Unit

Stream a reader's remaining bytes as one part, leaving both streams open.

parse_header_value

source

fn parse_header_value(value : String) -> (String, Map[@moonbitlang/async/http.CaseInsensitiveString
CaseInsensitiveString, String]) raise MultipartError

Parses an unfolded MIME field value, such as Content-Type or Content-Disposition. The main value is a token or type/subtype; parameter names are case-insensitive. Main values and parameter values retain their case. Comments are ignored and quoted pairs are unescaped; percent escapes and extended parameters stay raw. Grammar: RFC 2045 §5.1 and RFC 2183 §2.

Source Files

Install

Download zip

A streaming multipart reader/writer library integrated with `moonbitlang/async`.

multipartform-data

Yoorkin

Apache-2.0

github.com/Yoorkin/multipart

Updated 14 days ago

11K downloads

Site source Report issue Modules Skills Build queue Statistics

multipart

#multipart

#Examples

#Tests

#Callback

#MultipartError

#Form

#Form::Form

#Form::next_part

#FormPart

#FormPart::content_type

#FormPart::filename

#FormPart::headers

#FormPart::name

#FormWriter

#FormWriter::FormWriter

#FormWriter::boundary

#FormWriter::content_type

#FormWriter::finish

#FormWriter::write_field

#FormWriter::write_file

#FormWriter::write_json

#FormWriter::write_part

#Reader

#Reader::Reader

#Reader::next_part

#Writer

#Writer::Writer

#Writer::finish

#Writer::write_part

#Writer::write_reader

#parse_header_value

Source Files

Callback

MultipartError

Form

Form::Form

Form::next_part

FormPart

FormPart::content_type

FormPart::filename

FormPart::headers

FormPart::name

FormWriter

FormWriter::FormWriter

FormWriter::boundary

FormWriter::content_type

FormWriter::finish

FormWriter::write_field

FormWriter::write_file

FormWriter::write_json

FormWriter::write_part

Reader

Reader::Reader

Reader::next_part

Writer

Writer::Writer

Writer::finish

Writer::write_part

Writer::write_reader

parse_header_value