Make form construction fallible

examples/simple.rs

@@ -11,8 +11,8 @@ impl FormData for UploadedContent {
     type Item = ();
     type Error = Error;
 
-    fn form(_: &HttpRequest) -> Form<Self::Item, Self::Error> {
+    fn form(_: &HttpRequest) -> Result<Form<Self::Item, Self::Error>, Self::Error> {
-        Form::new()
+        Ok(Form::new()
             .field("Hey", Field::text())
             .field(
                 "Hi",
@@ -29,7 +29,7 @@ impl FormData for UploadedContent {
                     }
                     Ok(()) as Result<(), Error>
                 })),
-            )
+            ))
     }
 
     fn extract(value: Value<Self::Item>) -> Result<Self, Self::Error>

examples/upload.rs

@@ -61,11 +61,11 @@ impl FormData for UploadedContent {
     type Item = PathBuf;
     type Error = Errors;
 
-    fn form(req: &HttpRequest) -> Form<Self::Item, Self::Error> {
+    fn form(req: &HttpRequest) -> Result<Form<Self::Item, Self::Error>, Self::Error> {
         let file_count = req.app_data::<Arc<AtomicUsize>>().expect("Set config");
         let file_count = Arc::clone(file_count);
 
-        Form::new()
+        Ok(Form::new()
             .field("Hey", Field::text())
             .field(
                 "Hi",
@@ -85,7 +85,7 @@ impl FormData for UploadedContent {
                             .map_err(Errors::from)
                     }
                 })),
-            )
+            ))
     }
 
     fn extract(value: Value<Self::Item>) -> Result<Self, Self::Error>

src/extractor.rs

@@ -9,7 +9,7 @@ pub trait FormData {
     type Item: 'static;
     type Error: ResponseError + 'static;
 
-    fn form(req: &HttpRequest) -> Form<Self::Item, Self::Error>;
+    fn form(req: &HttpRequest) -> Result<Form<Self::Item, Self::Error>, Self::Error>;
 
     fn extract(value: Value<Self::Item>) -> Result<Self, Self::Error>
     where
@@ -27,9 +27,11 @@ where
 
     fn from_request(req: &HttpRequest, payload: &mut Payload) -> Self::Future {
         let multipart = actix_multipart::Multipart::new(req.headers(), payload.take());
-        let form = Rc::new(T::form(req));
+        let res = T::form(req);
 
         Box::pin(async move {
+            let form = Rc::new(res?);
+
             let uploaded = match handle_multipart(multipart, Rc::clone(&form)).await {
                 Ok(Ok(uploaded)) => uploaded,
                 Ok(Err(e)) => return Err(e.into()),

src/lib.rs

@@ -38,8 +38,8 @@
 //!     type Item = ();
 //!     type Error = Error;
 //!
-//!     fn form(_: &HttpRequest) -> Form<Self::Item, Self::Error> {
+//!     fn form(_: &HttpRequest) -> Result<Form<Self::Item, Self::Error>, Self::Error> {
-//!         Form::new()
+//!         Ok(Form::new()
 //!             .field("Hey", Field::text())
 //!             .field(
 //!                 "Hi",
@@ -56,7 +56,7 @@
 //!                     }
 //!                     Ok(()) as Result<(), Error>
 //!                 })),
-//!             )
+//!             ))
 //!     }
 //!
 //!     fn extract(value: Value<Self::Item>) -> Result<Self, Self::Error>

src/upload.rs

@@ -281,6 +281,8 @@ where
 
             if !stream_error {
                 while let Some(res) = m.next().await {
+                    tracing::trace!("draining multipart field");
+
                     if let Ok(field) = res {
                         let mut stream = field.into_streamer();
                         while stream.next().await.is_some() {