Allow custom error types through a macro and allow them to be used with Result

gotham_restful/src/result/auth_result.rs

@@ -0,0 +1,107 @@
+use gotham_restful_derive::ResourceError;
+
+
+/**
+This is an error type that always yields a _403 Forbidden_ response. This type is best used in
+combination with [`AuthSuccess`] or [`AuthResult`].
+
+  [`AuthSuccess`]: type.AuthSuccess.html
+  [`AuthResult`]: type.AuthResult.html
+*/
+#[derive(ResourceError)]
+pub enum AuthError
+{
+	#[status(FORBIDDEN)]
+	#[display("Forbidden")]
+	Forbidden
+}
+
+/**
+This return type can be used to map another `ResourceResult` that can only be returned if the
+client is authenticated. Otherwise, an empty _403 Forbidden_ response will be issued. Use can
+look something like this (assuming the `auth` feature is enabled):
+
+```
+# #[macro_use] extern crate gotham_restful_derive;
+# mod doc_tests_are_broken {
+# use gotham::state::State;
+# use gotham_restful::*;
+# use serde::Deserialize;
+#
+# #[derive(Resource)]
+# struct MyResource;
+#
+# #[derive(Clone, Deserialize)]
+# struct MyAuthData { exp : u64 }
+#
+#[rest_read_all(MyResource)]
+fn read_all(auth : AuthStatus<MyAuthData>) -> AuthSuccess<NoContent> {
+	let auth_data = match auth {
+		AuthStatus::Authenticated(data) => data,
+		_ => return Err(Forbidden)
+	};
+	// do something
+	Ok(NoContent::default())
+}
+# }
+```
+*/
+pub type AuthSuccess<T> = Result<T, AuthError>;
+
+/**
+This is an error type that either yields a _403 Forbidden_ respone if produced from an authentication
+error, or delegates to another error type. This type is best used with [`AuthResult`].
+
+  [`AuthResult`]: type.AuthResult.html
+*/
+#[derive(ResourceError)]
+pub enum AuthErrorOrOther<E>
+{
+	#[status(UNAUTHORIZED)]
+	#[display("Forbidden")]
+	Forbidden,
+	#[display("{0}")]
+	Other(#[from] E)
+}
+
+impl<E> From<AuthError> for AuthErrorOrOther<E>
+{
+	fn from(err : AuthError) -> Self
+	{
+		match err {
+			AuthError::Forbidden => Self::Forbidden
+		}
+	}
+}
+
+/**
+This return type can be used to map another `ResourceResult` that can only be returned if the
+client is authenticated. Otherwise, an empty _403 Forbidden_ response will be issued. Use can
+look something like this (assuming the `auth` feature is enabled):
+
+```
+# #[macro_use] extern crate gotham_restful_derive;
+# mod doc_tests_are_broken {
+# use gotham::state::State;
+# use gotham_restful::*;
+# use serde::Deserialize;
+# use std::io;
+#
+# #[derive(Resource)]
+# struct MyResource;
+#
+# #[derive(Clone, Deserialize)]
+# struct MyAuthData { exp : u64 }
+#
+#[rest_read_all(MyResource)]
+fn read_all(auth : AuthStatus<MyAuthData>) -> AuthResult<NoContent, io::Error> {
+	let auth_data = match auth {
+		AuthStatus::Authenticated(data) => data,
+		_ => Err(Forbidden)?
+	};
+	// do something
+	Ok(NoContent::default().into())
+}
+# }
+*/
+pub type AuthResult<T, E> = Result<T, AuthErrorOrOther<E>>;