Extend custom rejection examples (#1276)

* examples: Created new `error-handling` example * examples(error-handling): Add error codes and responses * examples(error-handling): `custom_extractor` * examples(error-handling): `derive_from_request` * examples(error-handling): Using POST instead of GET * examples(error-handling): Using `thiserror` for `derive_from_request` * examples(error-handling): Using `snake-case` for routes * revert(error-handling): Use `From` impl instead of `thiserror` refs: 3533d96215 * examples(error-handling): Removed chrono * examples: merged `error-handling` and `customize-extractor-error` * examples(customize-extractor-error): Improved error codes * examples(customize-extractor-error): rustfmt * examples(customize-extractor-error): Removed `matched-path` feature Co-authored-by: David Pedersen <[email protected]> * examples(customize-extractor-error): added `publish=false` to `Cargo.toml` Co-authored-by: David Pedersen <[email protected]> * examples(customize-extractor-error): Fix env filter * examples(customize-extractor-error): Added README * examples(customize-extractor-error): Added `with_rejection` comments * examples(customize-extractor-error): Added `custom_extractor` comments * examples(customize-extractor-error):Typo on `with_rejection` * examples(customize-extractor-error): Added `boilerplate` con to `custom_extractor` * examples(customize-extractor-error): Added `derive_from_request` comments * examples(customize-extractor-error): typo impossible * examples(customize-extractor-error): typos * examples(customize-extractor-error): replaced `extensions` with `extract` * examples(customize-extractor-error): typo `from` Co-authored-by: David Pedersen <[email protected]> Co-authored-by: David Pedersen <[email protected]>
2026-08-26 00:00:23 +02:00 · 2022-08-19 13:11:03 +00:00
parent 18dd830b84
commit 789f51ba1a
6 changed files with 219 additions and 74 deletions
@@ -0,0 +1,60 @@
+//! Uses `axum_macros::FromRequest` to wrap another extractor and customize the
+//! rejection
+//!
+//! + Easy learning curve: Deriving `FromRequest` generates a `FromRequest`
+//!   implementation for your type using another extractor. You only need
+//!   to provide a `From` impl between the original rejection type and the
+//!   target rejection. Crates like [`thiserror`] can provide such conversion
+//!   using derive macros.
+//! - Boilerplate: Requires deriving `FromRequest` for every custom rejection
+//! - There are some known limitations: [FromRequest#known-limitations]
+//!
+//! [`thiserror`]: https://crates.io/crates/thiserror
+//! [FromRequest#known-limitations]: https://docs.rs/axum-macros/*/axum_macros/derive.FromRequest.html#known-limitations
+use axum::{extract::rejection::JsonRejection, http::StatusCode, response::IntoResponse};
+use axum_macros::FromRequest;
+use serde_json::{json, Value};
+
+pub async fn handler(Json(value): Json<Value>) -> impl IntoResponse {
+    Json(dbg!(value));
+}
+
+// create an extractor that internally uses `axum::Json` but has a custom rejection
+#[derive(FromRequest)]
+#[from_request(via(axum::Json), rejection(ApiError))]
+pub struct Json<T>(T);
+
+// We create our own rejection type
+#[derive(Debug)]
+pub struct ApiError {
+    code: StatusCode,
+    message: String,
+}
+
+// We implement `From<JsonRejection> for ApiError`
+impl From<JsonRejection> for ApiError {
+    fn from(rejection: JsonRejection) -> Self {
+        let code = match rejection {
+            JsonRejection::JsonDataError(_) => StatusCode::UNPROCESSABLE_ENTITY,
+            JsonRejection::JsonSyntaxError(_) => StatusCode::BAD_REQUEST,
+            JsonRejection::MissingJsonContentType(_) => StatusCode::UNSUPPORTED_MEDIA_TYPE,
+            _ => StatusCode::INTERNAL_SERVER_ERROR,
+        };
+        Self {
+            code,
+            message: rejection.to_string(),
+        }
+    }
+}
+
+// We implement `IntoResponse` so ApiError can be used as a response
+impl IntoResponse for ApiError {
+    fn into_response(self) -> axum::response::Response {
+        let payload = json!({
+            "message": self.message,
+            "origin": "derive_from_request"
+        });
+
+        (self.code, axum::Json(payload)).into_response()
+    }
+}