pub struct Multipart { /* private fields */ }multipart only.Expand description
Extractor that parses multipart/form-data requests (commonly used with file uploads).
⚠️ Since extracting multipart form data from the request requires consuming the body, the
Multipart extractor must be last if there are multiple extractors in a handler.
See “the order of extractors”
§Example
use axum::{
routing::post,
Router,
};
use axum_extra::extract::Multipart;
async fn upload(mut multipart: Multipart) {
while let Some(mut field) = multipart.next_field().await.unwrap() {
let name = field.name().unwrap().to_string();
let data = field.bytes().await.unwrap();
println!("Length of `{}` is {} bytes", name, data.len());
}
}
let app = Router::new().route("/upload", post(upload));§Field Exclusivity
A Field represents a raw, self-decoding stream into multipart data. As such, only one
Field from a given Multipart instance may be live at once. That is, a Field emitted by
next_field() must be dropped before calling next_field() again. Failure to do so will
result in an error.
use axum_extra::extract::Multipart;
async fn handler(mut multipart: Multipart) {
let field_1 = multipart.next_field().await;
// We cannot get the next field while `field_1` is still alive. Have to drop `field_1`
// first.
let field_2 = multipart.next_field().await;
assert!(field_2.is_err());
}In general you should consume Multipart by looping over the fields in order and make sure not
to keep Fields around from previous loop iterations. That will minimize the risk of runtime
errors.
§Differences between this and axum::extract::Multipart
axum::extract::Multipart uses lifetimes to enforce field exclusivity at compile time, however
that leads to significant usability issues such as Field not being 'static.
axum_extra::extract::Multipart instead enforces field exclusivity at runtime which makes
things easier to use at the cost of possible runtime errors.
Implementations§
Source§impl Multipart
impl Multipart
Sourcepub async fn next_field(&mut self) -> Result<Option<Field>, MultipartError>
pub async fn next_field(&mut self) -> Result<Option<Field>, MultipartError>
Yields the next Field if available.
Sourcepub fn into_stream(
self,
) -> impl Stream<Item = Result<Field, MultipartError>> + Send + 'static
pub fn into_stream( self, ) -> impl Stream<Item = Result<Field, MultipartError>> + Send + 'static
Convert the Multipart into a stream of its fields.