diesel_derives/
identifiable.rs

1use proc_macro2::TokenStream;
2use quote::quote;
3use syn::parse_quote;
4use syn::DeriveInput;
5use syn::Result;
6
7use crate::model::Model;
8use crate::util::wrap_in_dummy_mod;
9
10pub fn derive(item: DeriveInput) -> Result<TokenStream> {
11    let model = Model::from_item(&item, false, false)?;
12
13    let struct_name = &item.ident;
14    let table_name = &model.table_names()[0];
15
16    let (impl_generics, ty_generics, where_clause) = item.generics.split_for_impl();
17    let mut ref_generics = item.generics.clone();
18    ref_generics.params.push(parse_quote!('ident));
19    let (ref_generics, ..) = ref_generics.split_for_impl();
20
21    let mut field_ty = Vec::new();
22    let mut field_name = Vec::new();
23    for pk in model.primary_key_names.iter() {
24        let f = model.find_column(pk)?;
25        field_ty.push(&f.ty);
26        field_name.push(&f.name);
27    }
28
29    Ok(wrap_in_dummy_mod(quote! {
30        use diesel::associations::{HasTable, Identifiable};
31
32        impl #impl_generics HasTable for #struct_name #ty_generics
33        #where_clause
34        {
35            type Table = #table_name::table;
36
37            fn table() -> Self::Table {
38                #table_name::table
39            }
40        }
41
42        impl #ref_generics Identifiable for &'ident #struct_name #ty_generics
43        #where_clause
44        {
45            type Id = (#(&'ident #field_ty),*);
46
47            fn id(self) -> Self::Id {
48                (#(&self.#field_name),*)
49            }
50        }
51
52        impl #ref_generics Identifiable for &'_ &'ident #struct_name #ty_generics
53            #where_clause
54        {
55            type Id = (#(&'ident #field_ty),*);
56
57            fn id(self) -> Self::Id {
58                (#(&self.#field_name),*)
59            }
60        }
61    }))
62}