sea-orm/sea-orm-macros/src/derives/into_active_model.rs

103 lines
2.8 KiB
Rust

use bae::FromAttributes;
use proc_macro2::{Span, TokenStream};
use quote::{quote, quote_spanned};
#[derive(Default, FromAttributes)]
pub struct SeaOrm {
pub active_model: Option<syn::Ident>,
}
enum Error {
InputNotStruct,
Syn(syn::Error),
}
struct IntoActiveModel {
attrs: SeaOrm,
fields: syn::punctuated::Punctuated<syn::Field, syn::token::Comma>,
field_idents: Vec<syn::Ident>,
ident: syn::Ident,
}
impl IntoActiveModel {
fn new(input: syn::DeriveInput) -> Result<Self, Error> {
let fields = match input.data {
syn::Data::Struct(syn::DataStruct {
fields: syn::Fields::Named(syn::FieldsNamed { named, .. }),
..
}) => named,
_ => return Err(Error::InputNotStruct),
};
let attrs = SeaOrm::try_from_attributes(&input.attrs)
.map_err(Error::Syn)?
.unwrap_or_default();
let ident = input.ident;
let field_idents = fields
.iter()
.map(|field| field.ident.as_ref().unwrap().clone())
.collect();
Ok(IntoActiveModel {
attrs,
fields,
field_idents,
ident,
})
}
fn expand(&self) -> syn::Result<TokenStream> {
let expanded_impl_into_active_model = self.impl_into_active_model();
Ok(expanded_impl_into_active_model)
}
fn impl_into_active_model(&self) -> TokenStream {
let Self {
attrs,
ident,
field_idents,
fields,
} = self;
let active_model_ident = attrs
.active_model
.clone()
.unwrap_or_else(|| syn::Ident::new("ActiveModel", Span::call_site()));
let expanded_fields_into_active_model = fields.iter().map(|field| {
let field_ident = field.ident.as_ref().unwrap();
quote!(
sea_orm::IntoActiveValue::<_>::into_active_value(self.#field_ident).into()
)
});
quote!(
#[automatically_derived]
impl sea_orm::IntoActiveModel<#active_model_ident> for #ident {
fn into_active_model(self) -> #active_model_ident {
#active_model_ident {
#( #field_idents: #expanded_fields_into_active_model, )*
..::std::default::Default::default()
}
}
}
)
}
}
pub fn expand_into_active_model(input: syn::DeriveInput) -> syn::Result<TokenStream> {
let ident_span = input.ident.span();
match IntoActiveModel::new(input) {
Ok(model) => model.expand(),
Err(Error::InputNotStruct) => Ok(quote_spanned! {
ident_span => compile_error!("you can only derive IntoActiveModel on structs");
}),
Err(Error::Syn(err)) => Err(err),
}
}