`flare.http.multipart`

multipart/form-data parsing (RFC 7578).

Browsers emit multipart/form-data for forms with file inputs or a non-default enctype. The body is a sequence of parts separated by a boundary string declared in the request's Content-Type: multipart/form-data; boundary=<token> header. Each part has its own headers and body bytes; binary file uploads do not need any encoding (text fields stay verbatim too).

Wire format:

--boundary\r\n
Content-Disposition: form-data; name="<field>"; filename="<file>"\r\n
Content-Type: <mime>\r\n
\r\n
<bytes...>\r\n
--boundary\r\n
Content-Disposition: form-data; name="<text-field>"\r\n
\r\n
<text...>\r\n
--boundary--\r\n

This module ships:

MultipartPart — one form part: name, optional filename, optional content type, body bytes, raw header map.
MultipartForm — name → part(s) collection; supports lookup by name plus iteration in receive order.
parse_multipart_form_data — bytes + Content-Type header → MultipartForm. The Multipart extractor in extract.mojo is the typed wrapper.

The parser is buffered (the entire body is a List[UInt8] already held by Request.body); a streaming variant on top of ChunkSource is left for a future revision when uploads exceed ServerConfig.max_body_size.

Structs

`MultipartPart`

struct MultipartPart

A single part inside a multipart/form-data body.

Fields: name: name="..." from Content-Disposition; empty if absent (treated as malformed). filename: filename="..." if present (file uploads); empty for plain text fields. content_type: Content-Type of this part if specified; empty otherwise (defaults to text/plain; charset=US-ASCII per RFC 7578 §4.4 if a consumer needs a non-empty fallback). body: The part's raw payload bytes (no trailing CRLF). headers: Every header line for this part as a parallel List[String] pair.

Implements Copyable, Movable

Fields: name: String; filename: String; content_type: String; body: List[UInt8]; header_keys: List[String]; header_values: List[String]

`init`

def __init__(out self)

`text`

def text(self) -> String

Decode the part body as a UTF-8 String.

Invalid UTF-8 sequences are replaced with the Unicode replacement character: part bodies are raw client-supplied bytes (RFC 7578 §4.2), so this never raises on malformed input.

`is_file`

def is_file(self) -> Bool

Return True if this part represents a file upload (has filename).

`header`

def header(self, key: String) -> String

Return part-level header key (case-insensitive), or "".

`MultipartForm`

struct MultipartForm

All parts of a parsed multipart/form-data body in receive order.

Implements Copyable, Defaultable, Movable

Fields: parts: List[MultipartPart]

`init`

def __init__(out self)

`len`

def len(self) -> Int

Return the number of parts in this form.

`get`

def get(self, name: String) -> Optional[MultipartPart]

Return the first part whose Content-Disposition name matches.

`get_all`

def get_all(self, name: String) -> List[MultipartPart]

Return every part with Content-Disposition name == name.

`value`

def value(self, name: String) -> String

Convenience: return the first text value for name or "".

`file`

def file(self, name: String) -> Optional[MultipartPart]

Return the first file part whose name matches, or None.

`contains`

def contains(self, name: String) -> Bool

Return True if any part with name exists.

Functions

`parse_multipart_form_data`

def parse_multipart_form_data(body: List[UInt8], content_type: String) -> MultipartForm

Parse a buffered multipart/form-data body.

Args: body: The raw request body bytes.; content_type: The request's Content-Type header value (must include boundary=<token>).

Raises Error: When the boundary parameter is missing, the body does not begin with the expected delimiter, or any part is truncated (no closing CRLF before the next boundary).