feat: allow multipart forms on server fns (Actix) (#1048)

integrations/actix/Cargo.toml

@@ -8,6 +8,7 @@ repository = "https://github.com/leptos-rs/leptos"
 description = "Actix integrations for the Leptos web framework."
 
 [dependencies]
+actix-http = "3"
 actix-web = "4"
 futures = "0.3"
 leptos = { workspace = true, features = ["ssr"] }

integrations/actix/src/lib.rs

@@ -185,7 +185,7 @@ pub fn handle_server_fns_with_context(
                     .and_then(|value| value.to_str().ok());
 
                 if let Some(server_fn) = server_fn_by_path(path.as_str()) {
-                    let body: &[u8] = &body;
+                    let body_ref: &[u8] = &body;
 
                     let runtime = create_runtime();
                     let (cx, disposer) = raw_scope_and_disposer(runtime);
@@ -198,10 +198,28 @@ pub fn handle_server_fns_with_context(
                     provide_context(cx, req.clone());
                     provide_context(cx, res_options.clone());
 
+                    // we consume the body here (using the web::Bytes extractor), but it is required for things
+                    // like MultipartForm
+                    if req
+                        .headers()
+                        .get("Content-Type")
+                        .and_then(|value| value.to_str().ok())
+                        .and_then(|value| {
+                            Some(
+                                value.starts_with(
+                                    "multipart/form-data; boundary=",
+                                ),
+                            )
+                        })
+                        == Some(true)
+                    {
+                        provide_context(cx, body.clone());
+                    }
+
                     let query = req.query_string().as_bytes();
 
                     let data = match &server_fn.encoding {
-                        Encoding::Url | Encoding::Cbor => body,
+                        Encoding::Url | Encoding::Cbor => body_ref,
                         Encoding::GetJSON | Encoding::GetCBOR => query,
                     };
                     let res = match (server_fn.trait_obj)(cx, data).await {
@@ -1072,9 +1090,17 @@ where
 {
     let req = use_context::<actix_web::HttpRequest>(cx)
         .expect("HttpRequest should have been provided via context");
-    let input = E::extract(&req)
-        .await
-        .map_err(|e| ServerFnError::ServerError(e.to_string()))?;
+
+    let input = if let Some(body) = use_context::<Bytes>(cx) {
+        let (_, mut payload) = actix_http::h1::Payload::create(false);
+        payload.unread_data(body);
+        E::from_request(&req, &mut dev::Payload::from(payload))
+    } else {
+        E::extract(&req)
+    }
+    .await
+    .map_err(|e| ServerFnError::ServerError(e.to_string()))?;
+
     Ok(f.call(input).await)
 }
 

router/src/components/form.rs

@@ -95,8 +95,63 @@ where
             let action = use_resolved_path(cx, move || action.clone())
                 .get()
                 .unwrap_or_default();
+            // multipart POST (setting Context-Type breaks the request)
+            if method == "post" && enctype == "multipart/form-data" {
+                ev.prevent_default();
+                ev.stop_propagation();
+
+                let on_response = on_response.clone();
+                spawn_local(async move {
+                    let res = gloo_net::http::Request::post(&action)
+                        .header("Accept", "application/json")
+                        .redirect(RequestRedirect::Follow)
+                        .body(form_data)
+                        .send()
+                        .await;
+                    match res {
+                        Err(e) => {
+                            error!("<Form/> error while POSTing: {e:#?}");
+                            if let Some(error) = error {
+                                error.set(Some(Box::new(e)));
+                            }
+                        }
+                        Ok(resp) => {
+                            if let Some(version) = action_version {
+                                version.update(|n| *n += 1);
+                            }
+                            if let Some(error) = error {
+                                error.set(None);
+                            }
+                            if let Some(on_response) = on_response.clone() {
+                                on_response(resp.as_raw());
+                            }
+                            // Check all the logical 3xx responses that might
+                            // get returned from a server function
+                            if resp.redirected() {
+                                let resp_url = &resp.url();
+                                match Url::try_from(resp_url.as_str()) {
+                                    Ok(url) => {
+                                        request_animation_frame(move || {
+                                            if let Err(e) = navigate(
+                                                &format!(
+                                                    "{}{}",
+                                                    url.pathname, url.search,
+                                                ),
+                                                Default::default(),
+                                            ) {
+                                                warn!("{}", e);
+                                            }
+                                        });
+                                    }
+                                    Err(e) => warn!("{}", e),
+                                }
+                            }
+                        }
+                    }
+                });
+            }
             // POST
-            if method == "post" {
+            else if method == "post" {
                 ev.prevent_default();
                 ev.stop_propagation();