Struct Form 

pub struct Form { /* private fields */ }

Available on crate feature multipart only.

A multipart form body.

Generates a random boundary on construction. Add named Parts with text, bytes, file, or part, then convert to a Body (or feed via RequestBuilder::multipart).

Implementations

impl Form

pub fn new() -> Self

Create a new empty Form with a random boundary.

pub fn boundary(&self) -> &str

The boundary string used to separate this form’s parts.

pub fn content_type(&self) -> HeaderValue

The Content-Type header value (multipart/form-data; boundary=…).

pub fn text<N, V>(self, name: N, value: V) -> Self

where N: Into<Cow<'static, str>>, V: Into<Cow<'static, str>>,

Add a text part to the form.

pub fn bytes<N, B>(self, name: N, value: B) -> Self

where N: Into<Cow<'static, str>>, B: Into<Bytes>,

Add a bytes part to the form.

pub async fn file<N, P>(self, name: N, path: P) -> Result<Self>

where N: Into<Cow<'static, str>>, P: AsRef<Path>,

Add a file part to the form. Reads the file asynchronously, infers the MIME type from the file extension (falling back to application/octet-stream), and sets filename from the path.

pub async fn with_field_spec(self, spec: &str) -> Result<Self, FieldSpecError>

Add a part described by a compact name=value field-spec string.

See FieldSpec for the supported syntax (the same convention used by curl -F, httpie, and similar tools). Performs the I/O implied by =@ (file), =< (file-as-text), and =@- / =<- (stdin) sources; the =value form is purely textual.

pub fn part<N>(self, name: N, part: Part) -> Self

where N: Into<Cow<'static, str>>,

Add a custom Part to the form.

pub fn content_length(&self) -> Option<u64>

Total content length of the encoded form, if every part has a known size. Returns None otherwise (use chunked transfer encoding in that case).

Computed analytically — no headers are rendered into a buffer.

pub fn into_stream(self) -> impl Stream<Item = Result<Bytes, BoxError>> + Send

Convert this form into a stream of body chunks.

Per-part overhead: one heap-allocated framing chunk (boundary delimiter + headers, prefixed with CRLF on all but the first part) and the part body. Bytes-bodied parts are emitted in a single chunk; streamed bodies pass through their underlying chunks unchanged.

pub fn into_body(self) -> Body

Consume the form and produce a Body ready to be set on a request. Use content_type and content_length to set the relevant request headers.

Trait Implementations

impl Debug for Form

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Form

fn default() -> Self

Returns the “default value” for a type.