Added initial support for PathConfig, allows setting custom error handler. (#903)

src/error.rs

@@ -92,6 +92,25 @@ impl ResponseError for JsonPayloadError {
     }
 }
 
+/// A set of errors that can occur during parsing request paths
+#[derive(Debug, Display, From)]
+pub enum PathPayloadError {
+    /// Deserialize error
+    #[display(fmt = "Path deserialize error: {}", _0)]
+    Deserialize(de::Error),
+}
+
+/// Return `BadRequest` for `PathPayloadError`
+impl ResponseError for PathPayloadError {
+    fn error_response(&self) -> HttpResponse {
+        match *self {
+            PathPayloadError::Deserialize(_) => {
+                HttpResponse::new(StatusCode::BAD_REQUEST)
+            }
+        }
+    }
+}
+
 /// A set of errors that can occur during parsing query strings
 #[derive(Debug, Display, From)]
 pub enum QueryPayloadError {

src/types/mod.rs

@@ -9,6 +9,6 @@ pub(crate) mod readlines;
 
 pub use self::form::{Form, FormConfig};
 pub use self::json::{Json, JsonConfig};
-pub use self::path::Path;
+pub use self::path::{Path, PathConfig};
 pub use self::payload::{Payload, PayloadConfig};
 pub use self::query::{Query, QueryConfig};

src/types/path.rs

@@ -1,5 +1,6 @@
 //! Path extractor
 
+use std::sync::Arc;
 use std::{fmt, ops};
 
 use actix_http::error::{Error, ErrorNotFound};
@@ -7,6 +8,7 @@ use actix_router::PathDeserializer;
 use serde::de;
 
 use crate::dev::Payload;
+use crate::error::PathPayloadError;
 use crate::request::HttpRequest;
 use crate::FromRequest;
 
@@ -156,15 +158,89 @@ impl<T> FromRequest for Path<T>
 where
     T: de::DeserializeOwned,
 {
-    type Config = ();
     type Error = Error;
     type Future = Result<Self, Error>;
+    type Config = PathConfig;
 
     #[inline]
     fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
+        let error_handler = req
+            .app_data::<Self::Config>()
+            .map(|c| c.ehandler.clone())
+            .unwrap_or(None);
+
         de::Deserialize::deserialize(PathDeserializer::new(req.match_info()))
             .map(|inner| Path { inner })
-            .map_err(ErrorNotFound)
+            .map_err(move |e| {
+                log::debug!(
+                    "Failed during Path extractor deserialization. \
+                     Request path: {:?}",
+                    req.path()
+                );
+                if let Some(error_handler) = error_handler {
+                    let e = PathPayloadError::Deserialize(e);
+                    (error_handler)(e, req)
+                } else {
+                    ErrorNotFound(e)
+                }
+            })
+    }
+}
+
+/// Path extractor configuration
+///
+/// ```rust
+// #[macro_use]
+// extern crate serde_derive;
+// use actix_web::web::PathConfig;
+// use actix_web::{error, web, App, FromRequest, HttpResponse};
+
+// #[derive(Deserialize, Debug)]
+// enum Folder {
+//     #[serde(rename = "inbox")]
+//     Inbox,
+//     #[serde(rename = "outbox")]
+//     Outbox,
+// }
+
+// /// deserialize `Info` from request's path
+// fn index(folder: web::Path<Folder>) -> String {
+//     format!("Selected folder: {}!", folder)
+// }
+
+// fn main() {
+//     let app = App::new().service(
+//         web::resource("messages/{folder}")
+//             .data(PathConfig::default().error_handler(|err, req| {
+//                 error::InternalError::from_response(
+//                     err,
+//                     HttpResponse::Conflict().finish(),
+//                 )
+//                 .into()
+//             }))
+//             .route(web::post().to(index)),
+//     );
+// }
+/// ```
+#[derive(Clone)]
+pub struct PathConfig {
+    ehandler: Option<Arc<Fn(PathPayloadError, &HttpRequest) -> Error + Send + Sync>>,
+}
+
+impl PathConfig {
+    /// Set custom error handler
+    pub fn error_handler<F>(mut self, f: F) -> Self
+    where
+        F: Fn(PathPayloadError, &HttpRequest) -> Error + Send + Sync + 'static,
+    {
+        self.ehandler = Some(Arc::new(f));
+        self
+    }
+}
+
+impl Default for PathConfig {
+    fn default() -> Self {
+        PathConfig { ehandler: None }
     }
 }