Merge pull request #144 from SeaQL/ss/rocket-pagination

Add pagination to the rocket example

examples/rocket_example/src/main.rs

@@ -11,7 +11,6 @@ use rocket_db_pools::{sqlx, Connection, Database};
 use rocket_dyn_templates::{context, Template};
 
 use sea_orm::entity::*;
-use sea_orm::query::*;
 
 mod pool;
 use pool::RocketDbPool;
@@ -27,6 +26,8 @@ type Result<T, E = rocket::response::Debug<sqlx::Error>> = std::result::Result<T
 mod post;
 pub use post::Entity as Post;
 
+const DEFAULT_POSTS_PER_PAGE: usize = 5;
+
 #[get("/new")]
 fn new() -> Template {
     Template::render("new", &Context::default())
@@ -71,11 +72,20 @@ async fn update(conn: Connection<Db>, id: i32, post_form: Form<post::Model>) ->
     Flash::success(Redirect::to("/"), "Post successfully edited.")
 }
 
-#[get("/")]
-async fn list(conn: Connection<Db>, flash: Option<FlashMessage<'_>>) -> Template {
-    let posts = Post::find()
-        .order_by_asc(post::Column::Id)
-        .all(&conn)
+#[get("/?<page>&<posts_per_page>")]
+async fn list(
+    conn: Connection<Db>,
+    posts_per_page: Option<usize>,
+    page: Option<usize>,
+    flash: Option<FlashMessage<'_>>,
+) -> Template {
+    let page = page.unwrap_or(0);
+    let posts_per_page = posts_per_page.unwrap_or(DEFAULT_POSTS_PER_PAGE);
+    let paginator = Post::find().paginate(&conn, posts_per_page);
+    let num_pages = paginator.num_pages().await.ok().unwrap();
+
+    let posts = paginator
+        .fetch_page(page)
         .await
         .expect("could not retrieve posts");
 
@@ -86,6 +96,9 @@ async fn list(conn: Connection<Db>, flash: Option<FlashMessage<'_>>) -> Template
         context! {
             posts: posts,
             flash: flash,
+            page: page,
+            posts_per_page: posts_per_page,
+            num_pages: num_pages,
         },
     )
 }
@@ -138,7 +151,7 @@ pub fn not_found(req: &Request<'_>) -> Template {
 async fn run_migrations(rocket: Rocket<Build>) -> fairing::Result {
     let db_url = Db::fetch(&rocket).unwrap().db_url.clone();
     let conn = sea_orm::Database::connect(&db_url).await.unwrap();
-    setup::create_post_table(&conn).await;
+    let _ = setup::create_post_table(&conn).await;
     Ok(rocket)
 }
 

examples/rocket_example/templates/index.html.tera

@@ -22,6 +22,19 @@
     </tr>
     {% endfor %}
   </tbody>
+  <tfoot>
+    <tr>
+      <td></td>
+      <td>
+        {% if page == 0 %} Previous {% else %}
+        <a href="/?page={{ page - 1 }}&posts_per_page={{ posts_per_page }}">Previous</a>
+        {% endif %} | {% if page == num_pages - 1 %} Next {% else %}
+        <a href="/?page={{ page + 1 }}&posts_per_page={{ posts_per_page }}">Next</a>
+        {% endif %}
+      </td>
+      <td></td>
+    </tr>
+  </tfoot>
 </table>
 
 <div class="twelve columns">

src/query/helper.rs

@@ -3,7 +3,9 @@ use crate::{
     PrimaryKeyToColumn, RelationDef,
 };
 pub use sea_query::{Condition, ConditionalStatement, DynIden, JoinType, Order, OrderedStatement};
-use sea_query::{Expr, IntoCondition, LockType, SeaRc, SelectExpr, SelectStatement, SimpleExpr, TableRef};
+use sea_query::{
+    Expr, IntoCondition, LockType, SeaRc, SelectExpr, SelectStatement, SimpleExpr, TableRef,
+};
 
 // LINT: when the column does not appear in tables selected from
 // LINT: when there is a group by clause, but some columns don't have aggregate functions