Implement book list with Pagination

Author: sushant-at-nitor

packages/api/src/endpoints/books/list.rs

@@ -0,0 +1,47 @@
+use std::sync::Arc;
+use warp::Filter;
+
+use application::books::{
+  BookService, ListBooksQueryHandler, ListBooksQueryHandlerTrait,
+};
+use common::server_error::ServerError;
+use domain::queries::ListBooks;
+
+pub fn route<T>(
+  handler: Arc<ListBooksQueryHandler<T>>,
+) -> impl Filter<Extract = impl warp::Reply, Error = warp::Rejection> + Clone
+where
+  T: BookService + Send + Sync + 'static,
+{
+  // GET /books
+  warp::path!("books" / "list")
+    .and(warp::get())
+    .and(warp::query::<ListBooks>())
+    .and(with_handler(handler))
+    .and_then(handle_get_all_books)
+}
+
+fn with_handler<T>(
+  handler: Arc<ListBooksQueryHandler<T>>,
+) -> impl Filter<
+  Extract = (Arc<ListBooksQueryHandler<T>>,),
+  Error = std::convert::Infallible,
+> + Clone
+where
+  T: BookService + Send + Sync + 'static,
+{
+  warp::any().map(move || handler.clone())
+}
+
+async fn handle_get_all_books<T>(
+  query: ListBooks,
+  handler: Arc<ListBooksQueryHandler<T>>,
+) -> Result<impl warp::Reply, warp::Rejection>
+where
+  T: BookService + Send + Sync + 'static,
+{
+  match handler.handle(query).await {
+    Ok(books) => Ok(warp::reply::json(&books)),
+    Err(_) => Err(warp::reject::custom(ServerError)),
+  }
+}

packages/api/src/endpoints/books/mod.rs

@@ -2,17 +2,15 @@ mod create;
 mod delete;
 mod get_all;
 mod get_by_id;
+mod list;
 mod update;
 
 use std::sync::Arc;
 use warp::Filter;
 
 use application::books::{
-  command_handlers::CreateBookCommandHandler,
-  command_handlers::DeleteBookCommandHandler,
-  command_handlers::UpdateBookCommandHandler,
-  query_handlers::GetAllBooksQueryHandler,
-  query_handlers::GetBookByIdQueryHandler,
+  CreateBookCommandHandler, DeleteBookCommandHandler, GetAllBooksQueryHandler,
+  GetBookByIdQueryHandler, ListBooksQueryHandler, UpdateBookCommandHandler,
 };
 use infrastructure::{
   repositories::book_repository::BookRepository,
@@ -29,6 +27,7 @@ pub fn register(
   let create_handler = Arc::new(CreateBookCommandHandler::new(service.clone()));
   let update_handler = Arc::new(UpdateBookCommandHandler::new(service.clone()));
   let delete_handler = Arc::new(DeleteBookCommandHandler::new(service.clone()));
+  let list_handler = Arc::new(ListBooksQueryHandler::new(service.clone()));
   let get_all_handler = Arc::new(GetAllBooksQueryHandler::new(service.clone()));
   let get_by_id_handler =
     Arc::new(GetBookByIdQueryHandler::new(service.clone()));
@@ -37,10 +36,14 @@ pub fn register(
   let create = create::route(create_handler);
   let update = update::route(update_handler);
   let delete = delete::route(delete_handler);
+  let list = list::route(list_handler);
   let get_all = get_all::route(get_all_handler);
   let get_by_id = get_by_id::route(get_by_id_handler);
 
-  let routes = create.or(update).or(delete).or(get_all).or(get_by_id);
-
-  routes
+  create
+    .or(update)
+    .or(delete)
+    .or(list)
+    .or(get_all)
+    .or(get_by_id)
 }

packages/application/src/books/query_handlers/list_handler.rs

@@ -0,0 +1,33 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use common::{Paged, app_error::AppError};
+use domain::{aggregate::book::Book, queries::ListBooks};
+
+use crate::books::BookService;
+
+#[async_trait]
+pub trait ListBooksQueryHandlerTrait: Send + Sync {
+  async fn handle(&self, query: ListBooks) -> Result<Paged<Book>, AppError>;
+}
+
+pub struct ListBooksQueryHandler<T: BookService> {
+  service: Arc<T>,
+}
+
+impl<T: BookService> ListBooksQueryHandler<T> {
+  pub fn new(service: Arc<T>) -> Self {
+    Self { service }
+  }
+}
+
+#[async_trait]
+impl<T: BookService> ListBooksQueryHandlerTrait for ListBooksQueryHandler<T> {
+  async fn handle(&self, pager: ListBooks) -> Result<Paged<Book>, AppError> {
+    self
+      .service
+      .list(pager.page.unwrap_or(1), pager.page_size.unwrap_or(10))
+      .await
+      .map_err(|e| AppError::DatabaseError(e.to_string()))
+  }
+}

packages/domain/src/queries/book.rs

@@ -10,8 +10,10 @@ pub struct GetAllBooksQuery;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ListBooks {
-  pub page: u64,
-  pub page_size: u64,
+  #[serde(default)]
+  pub page: Option<u64>,
+  #[serde(default)]
+  pub page_size: Option<u64>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]