add partials

mongod_derive/src/lib.rs

@@ -42,6 +42,8 @@ pub fn model_derive(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
 
     let name = input.ident;
+    let name_str = name.to_string().to_snake();
+    let partial_name = syn::Ident::new(&format!("Partial{}", name), name.span());
 
     // Generate code for each field
     let field_code = if let Data::Struct(data_struct) = input.data {
@@ -91,8 +93,36 @@ pub fn model_derive(input: TokenStream) -> TokenStream {
                     }
                 }).collect();
 
+                let partial_struct: Vec<_> = fields_named
+                    .named
+                    .iter()
+                    .map(|field| {
+                        let field_name = &field.ident.as_ref().unwrap();
+                        let field_type = &field.ty;
+                        let field_name_str = field_name.to_string();
+
+                        if field_name_str == "_id" {
+                            return quote! {
+                                pub _id: String,
+                            };
+                        }
+
+                        if is_type(field_type, "Option") {
+                            return quote! {
+                                pub #field_name: #field_type,
+                            };
+                        }
+
+                        quote! {
+                            pub #field_name: Option<#field_type>,
+                        }
+                    })
+                    .collect();
+
                 quote! {
                     impl mongod::model::Model for #name {
+                        type Partial = #partial_name;
+
                         async fn update_values(
                             &mut self,
                             obj: &serde_json::Map<String, serde_json::Value>,
@@ -101,6 +131,21 @@ pub fn model_derive(input: TokenStream) -> TokenStream {
                             #( #field_process_code )*
                         }
                     }
+
+                    #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+                    pub struct #partial_name {
+                        #( #partial_struct )*
+                    }
+
+                    impl mongod::model::reference::Referencable for #partial_name {
+                        fn collection_name() -> &'static str {
+                            #name_str
+                        }
+
+                        fn id(&self) -> &str {
+                            &self._id
+                        }
+                    }
                 }
             }
             _ => unimplemented!(),