api-macro: support defining schemas for structs

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

proxmox-api-macro/src/api.rs

@@ -11,6 +11,7 @@ use syn::{ExprPath, Ident};
 use crate::util::{JSONObject, JSONValue};
 
 mod method;
+mod structs;
 
 /// The main `Schema` type.
 ///
@@ -353,7 +354,8 @@ pub(crate) fn api(attr: TokenStream, item: TokenStream) -> Result<TokenStream, E
     let item: syn::Item = syn::parse2(item)?;
 
     match item {
-        syn::Item::Fn(func) => method::handle_method(attribs, func),
+        syn::Item::Fn(item) => method::handle_method(attribs, item),
+        syn::Item::Struct(item) => structs::handle_struct(attribs, item),
         _ => bail!(item => "api macro only works on functions"),
     }
 }

proxmox-api-macro/src/api/structs.rs

@@ -0,0 +1,31 @@
+use std::convert::TryInto;
+
+use failure::Error;
+
+use proc_macro2::TokenStream;
+use quote::quote_spanned;
+
+use super::Schema;
+use crate::util::JSONObject;
+
+/// Parse `input`, `returns` and `protected` attributes out of an function annotated
+/// with an `#[api]` attribute and produce a `const ApiMethod` named after the function.
+///
+/// See the top level macro documentation for a complete example.
+pub fn handle_struct(attribs: JSONObject, stru: syn::ItemStruct) -> Result<TokenStream, Error> {
+    let schema = {
+        let schema: Schema = attribs.try_into()?;
+        let mut ts = TokenStream::new();
+        schema.to_schema(&mut ts)?;
+        ts
+    };
+
+    let name = &stru.ident;
+
+    Ok(quote_spanned! { name.span() =>
+        #stru
+        impl #name {
+            pub const API_SCHEMA: &'static ::proxmox::api::schema::Schema = #schema;
+        }
+    })
+}

proxmox-api-macro/tests/types.rs

@@ -5,12 +5,20 @@ use proxmox::api::schema;
 use proxmox_api_macro::api;
 
 use failure::Error;
-use serde::{Deserialize, Serialize};
+//use serde::{Deserialize, Serialize};
+use serde_json::Value;
 
-#[derive(Clone, Debug, Deserialize, Serialize)]
+#[api(
+    type: String,
+    description: "A string",
+    format: &schema::ApiStringFormat::Enum(&["ok", "not-ok"]),
+)]
+//#[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct OkString(String);
+
+// generates the following without the '_' prefix in the constant:
 impl OkString {
-    pub const API_SCHEMA: &'static schema::Schema = &schema::StringSchema::new("A string")
+    pub const _API_SCHEMA: &'static schema::Schema = &schema::StringSchema::new("A string")
         .format(&schema::ApiStringFormat::Enum(&["ok", "not-ok"]))
         .schema();
 }
@@ -27,6 +35,7 @@ impl OkString {
 /// Check a string.
 ///
 /// Returns: Whether the string was "ok".
-pub fn string_check(arg: OkString) -> Result<bool, Error> {
-    Ok(arg.0 == "ok")
+pub fn string_check(arg: Value) -> Result<bool, Error> {
+    let _ = arg;
+    panic!("body")
 }