add proc macro derive for openapitype

gotham_restful/src/result.rs

@@ -0,0 +1,88 @@
+use crate::{ResourceType, StatusCode};
+#[cfg(feature = "openapi")]
+use crate::OpenapiSchema;
+use serde::Serialize;
+use serde_json::error::Error as SerdeJsonError;
+use std::error::Error;
+
+/// A trait provided to convert a resource's result to json.
+pub trait ResourceResult
+{
+	fn to_json(&self) -> Result<(StatusCode, String), SerdeJsonError>;
+	
+	#[cfg(feature = "openapi")]
+	fn to_schema() -> OpenapiSchema;
+}
+
+#[cfg(feature = "openapi")]
+impl<Res : ResourceResult> crate::OpenapiType for Res
+{
+	fn to_schema() -> OpenapiSchema
+	{
+		Self::to_schema()
+	}
+}
+
+/// The default json returned on an 500 Internal Server Error.
+#[derive(Debug, Serialize)]
+pub struct ResourceError
+{
+	error : bool,
+	message : String
+}
+
+impl<T : ToString> From<T> for ResourceError
+{
+	fn from(message : T) -> Self
+	{
+		Self {
+			error: true,
+			message: message.to_string()
+		}
+	}
+}
+
+impl<R : ResourceType, E : Error> ResourceResult for Result<R, E>
+{
+	fn to_json(&self) -> Result<(StatusCode, String), SerdeJsonError>
+	{
+		Ok(match self {
+			Ok(r) => (StatusCode::OK, serde_json::to_string(r)?),
+			Err(e) => {
+				let err : ResourceError = e.into();
+				(StatusCode::INTERNAL_SERVER_ERROR, serde_json::to_string(&err)?)
+			}
+		})
+	}
+	
+	#[cfg(feature = "openapi")]
+	fn to_schema() -> OpenapiSchema
+	{
+		R::to_schema()
+	}
+}
+
+/// This can be returned from a resource when there is no cause of an error.
+pub struct Success<T>(T);
+
+impl<T> From<T> for Success<T>
+{
+	fn from(t : T) -> Self
+	{
+		Self(t)
+	}
+}
+
+impl<T : ResourceType> ResourceResult for Success<T>
+{
+	fn to_json(&self) -> Result<(StatusCode, String), SerdeJsonError>
+	{
+		Ok((StatusCode::OK, serde_json::to_string(&self.0)?))
+	}
+	
+	#[cfg(feature = "openapi")]
+	fn to_schema() -> OpenapiSchema
+	{
+		T::to_schema()
+	}
+}