add derive for raw request body

gotham_restful_derive/src/from_body.rs

@@ -0,0 +1,69 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{
+	Fields,
+	ItemStruct,
+	parse_macro_input
+};
+
+pub fn expand_from_body(tokens : TokenStream) -> TokenStream
+{
+	let krate = super::krate();
+	let input = parse_macro_input!(tokens as ItemStruct);
+	let ident = input.ident;
+	let generics = input.generics;
+	
+	let (were, body) = match input.fields {
+		Fields::Named(named) => {
+			let fields = named.named;
+			if fields.len() == 0 // basically unit
+			{
+				(quote!(), quote!(Self{}))
+			}
+			else if fields.len() == 1
+			{
+				let field = fields.first().unwrap();
+				let field_ident = field.ident.as_ref().unwrap();
+				let field_ty = &field.ty;
+				(quote!(where #field_ty : for<'a> From<&'a [u8]>), quote!(Self { #field_ident: body.into() }))
+			}
+			else
+			{
+				panic!("FromBody can only be derived for structs with at most one field")
+			}
+		},
+		Fields::Unnamed(unnamed) => {
+			let fields = unnamed.unnamed;
+			if fields.len() == 0 // basically unit
+			{
+				(quote!(), quote!(Self{}))
+			}
+			else if fields.len() == 1
+			{
+				let field = fields.first().unwrap();
+				let field_ty = &field.ty;
+				(quote!(where #field_ty : for<'a> From<&'a [u8]>), quote!(Self(body.into())))
+			}
+			else
+			{
+				panic!("FromBody can only be derived for structs with at most one field")
+			}
+		},
+		Fields::Unit => (quote!(), quote!(Self{}))
+	};
+	
+	let output = quote! {
+		impl #generics #krate::FromBody for #ident #generics
+		#were
+		{
+			type Err = String;
+			
+			fn from_body(body : #krate::Chunk, _content_type : #krate::Mime) -> Result<Self, Self::Err>
+			{
+				let body : &[u8] = &body;
+				Ok(#body)
+			}
+		}
+	};
+	output.into()
+}

gotham_restful_derive/src/lib.rs

@@ -4,8 +4,12 @@ use proc_macro::TokenStream;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 
+mod from_body;
+use from_body::expand_from_body;
 mod method;
 use method::{expand_method, Method};
+mod request_body;
+use request_body::expand_request_body;
 mod resource;
 use resource::expand_resource;
 #[cfg(feature = "openapi")]
@@ -16,6 +20,12 @@ fn krate() -> TokenStream2
 	quote!(::gotham_restful)
 }
 
+#[proc_macro_derive(FromBody)]
+pub fn derive_from_body(tokens : TokenStream) -> TokenStream
+{
+	expand_from_body(tokens)
+}
+
 #[cfg(feature = "openapi")]
 #[proc_macro_derive(OpenapiType)]
 pub fn derive_openapi_type(tokens : TokenStream) -> TokenStream
@@ -23,6 +33,12 @@ pub fn derive_openapi_type(tokens : TokenStream) -> TokenStream
 	openapi_type::expand(tokens)
 }
 
+#[proc_macro_derive(RequestBody, attributes(supported_types))]
+pub fn derive_request_body(tokens : TokenStream) -> TokenStream
+{
+	expand_request_body(tokens)
+}
+
 #[proc_macro_derive(Resource, attributes(rest_resource))]
 pub fn derive_resource(tokens : TokenStream) -> TokenStream
 {

gotham_restful_derive/src/request_body.rs

@@ -0,0 +1,91 @@
+use proc_macro::TokenStream;
+use proc_macro2::TokenStream as TokenStream2;
+use quote::quote;
+use syn::{
+	parse::{Parse, ParseStream, Result as SynResult},
+	punctuated::Punctuated,
+	token::Comma,
+	Generics,
+	Ident,
+	ItemStruct,
+	Path,
+	parenthesized,
+	parse_macro_input
+};
+
+struct MimeList(Punctuated<Path, Comma>);
+
+impl Parse for MimeList
+{
+	fn parse(input: ParseStream) -> SynResult<Self>
+	{
+		let content;
+		let _paren = parenthesized!(content in input);
+		let list : Punctuated<Path, Comma> = Punctuated::parse_separated_nonempty(&content)?;
+		Ok(Self(list))
+	}
+}
+
+#[cfg(not(feature = "openapi"))]
+fn impl_openapi_type(_ident : &Ident, _generics : &Generics) -> TokenStream2
+{
+	quote!()
+}
+
+#[cfg(feature = "openapi")]
+fn impl_openapi_type(ident : &Ident, generics : &Generics) -> TokenStream2
+{
+	let krate = super::krate();
+	
+	quote! {
+		impl #generics #krate::OpenapiType for #ident #generics
+		{
+			fn schema() -> #krate::OpenapiSchema
+			{
+				use #krate::{export::openapi::*, OpenapiSchema};
+				
+				OpenapiSchema::new(SchemaKind::Type(Type::String(StringType {
+					format: VariantOrUnknownOrEmpty::Item(StringFormat::Binary),
+					pattern: None,
+					enumeration: Vec::new()
+				})))
+			}
+		}
+	}
+}
+
+pub fn expand_request_body(tokens : TokenStream) -> TokenStream
+{
+	let krate = super::krate();
+	let input = parse_macro_input!(tokens as ItemStruct);
+	let ident = input.ident;
+	let generics = input.generics;
+	
+	let types : Vec<Path> = input.attrs.into_iter().filter(|attr|
+		attr.path.segments.iter().last().map(|segment| segment.ident.to_string()) == Some("supported_types".to_string()) // TODO wtf
+	).flat_map(|attr| {
+		let m : MimeList = syn::parse2(attr.tokens).expect("unable to parse attributes");
+		m.0.into_iter()
+	}).collect();
+	
+	let types = match types {
+		ref types if types.is_empty() => quote!(None),
+		types => quote!(Some(vec![#(#types),*]))
+	};
+	
+	let impl_openapi_type = impl_openapi_type(&ident, &generics);
+	
+	let output = quote! {
+		impl #generics #krate::RequestBody for #ident #generics
+		where #ident #generics : #krate::FromBody
+		{
+			fn supported_types() -> Option<Vec<#krate::Mime>>
+			{
+				#types
+			}
+		}
+		
+		#impl_openapi_type
+	};
+	output.into()
+}