From 67eb41add17b93ed273ff0668a14b366b0fabfa9 Mon Sep 17 00:00:00 2001
From: Bat <baptiste@gelez.xyz>
Date: Fri, 20 Jul 2018 18:42:35 +0200
Subject: [PATCH] Add pagination to the blog page

No UI to control it yet
---
 plume-models/src/posts.rs         |  9 +++++++
 src/main.rs                       |  1 +
 src/routes/blogs.rs               | 14 ++++++++---
 src/routes/mod.rs                 | 42 +++++++++++++++++++++++++++++--
 templates/blogs/details.html.tera |  4 +--
 5 files changed, 62 insertions(+), 8 deletions(-)

diff --git a/plume-models/src/posts.rs b/plume-models/src/posts.rs
index 856ec349..ecacedb0 100644
--- a/plume-models/src/posts.rs
+++ b/plume-models/src/posts.rs
@@ -91,6 +91,15 @@ impl Post {
             .expect("Error loading recent posts for blog")
     }
 
+    pub fn blog_page(conn: &PgConnection, blog: &Blog, (min, max): (i32, i32)) -> Vec<Post> {
+        posts::table.filter(posts::blog_id.eq(blog.id))
+            .order(posts::creation_date.desc())
+            .offset(min.into())
+            .limit((max - min).into())
+            .load::<Post>(conn)
+            .expect("Error loading a page of posts for blog")
+    }
+
     pub fn get_authors(&self, conn: &PgConnection) -> Vec<User> {
         use schema::users;
         use schema::post_authors;
diff --git a/src/main.rs b/src/main.rs
index 215e2101..c414e503 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -36,6 +36,7 @@ fn main() {
     let pool = setup::check();
     rocket::ignite()
         .mount("/", routes![
+            routes::blogs::paginated_details,
             routes::blogs::details,
             routes::blogs::activity_details,
             routes::blogs::outbox,
diff --git a/src/routes/blogs.rs b/src/routes/blogs.rs
index 1a42f405..9aa07141 100644
--- a/src/routes/blogs.rs
+++ b/src/routes/blogs.rs
@@ -18,24 +18,30 @@ use plume_models::{
     posts::Post,
     users::User
 };
+use routes::Page;
 
-#[get("/~/<name>", rank = 2)]
-fn details(name: String, conn: DbConn, user: Option<User>) -> Template {
+#[get("/~/<name>?<page>", rank = 2)]
+fn paginated_details(name: String, conn: DbConn, user: Option<User>, page: Page) -> Template {
     may_fail!(user, Blog::find_by_fqn(&*conn, name), "Requested blog couldn't be found", |blog| {
-        let recents = Post::get_recents_for_blog(&*conn, &blog, 5);
+        let posts = Post::blog_page(&*conn, &blog, page.limits());
         let authors = &blog.list_authors(&*conn);
 
         Template::render("blogs/details", json!({
             "blog": &blog,
             "account": user,
             "is_author": user.map(|x| x.is_author_in(&*conn, blog.clone())),
-            "recents": recents.into_iter().map(|p| p.to_json(&*conn)).collect::<Vec<serde_json::Value>>(),
+            "posts": posts.into_iter().map(|p| p.to_json(&*conn)).collect::<Vec<serde_json::Value>>(),
             "authors": authors.into_iter().map(|u| u.to_json(&*conn)).collect::<Vec<serde_json::Value>>(),
             "n_authors": authors.len()
         }))
     })    
 }
 
+#[get("/~/<name>", rank = 3)]
+fn details(name: String, conn: DbConn, user: Option<User>) -> Template {
+    paginated_details(name, conn, user, Page::first())
+}
+
 #[get("/~/<name>", rank = 1)]
 fn activity_details(name: String, conn: DbConn, _ap: ApRequest) -> ActivityStream<CustomGroup> {
     let blog = Blog::find_local(&*conn, name).unwrap();
diff --git a/src/routes/mod.rs b/src/routes/mod.rs
index 735cd4a1..8bfd4cf0 100644
--- a/src/routes/mod.rs
+++ b/src/routes/mod.rs
@@ -1,5 +1,11 @@
-use rocket::response::NamedFile;
-use std::path::{Path, PathBuf};
+use rocket::{
+    http::uri::{FromUriParam, UriDisplay},
+    response::NamedFile
+};
+use std::{
+    fmt,
+    path::{Path, PathBuf}
+};
 
 macro_rules! may_fail {
     ($account:expr, $expr:expr, $template:expr, $msg:expr, | $res:ident | $block:block) => {
@@ -28,6 +34,38 @@ macro_rules! may_fail {
     };
 }
 
+const ITEMS_PER_PAGE: i32 = 10;
+
+#[derive(FromForm)]
+pub struct Page {
+    page: i32
+}
+
+impl UriDisplay for Page {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "page={}", &self.page as &UriDisplay)
+    }
+}
+
+impl FromUriParam<i32> for Page {
+    type Target = Page;
+    fn from_uri_param(num: i32) -> Page {
+        Page { page: num }
+    }
+}
+
+impl Page {
+    pub fn first() -> Page {
+        Page {
+            page: 1
+        }
+    }
+
+    pub fn limits(&self) -> (i32, i32) {
+        ((self.page - 1) * ITEMS_PER_PAGE, self.page * ITEMS_PER_PAGE)
+    }
+}
+
 pub mod blogs;
 pub mod comments;
 pub mod errors;
diff --git a/templates/blogs/details.html.tera b/templates/blogs/details.html.tera
index 96d805c1..abe983b2 100644
--- a/templates/blogs/details.html.tera
+++ b/templates/blogs/details.html.tera
@@ -22,14 +22,14 @@
 
     <section>
         <h2>{{ "Latest articles" | _ }}</h2>
-        {% if recents | length < 1 %}
+        {% if posts | length < 1 %}
             <p>{{ "No posts to see here yet." | _ }}</p>
         {% endif %}
         {% if is_author %}
             <a href="new" class="button inline-block">{{ "New article" | _ }}</a>
         {% endif %}
         <div class="cards">
-            {% for article in recents %}
+            {% for article in posts %}
                 {{ macros::post_card(article=article) }}
             {% endfor %}
         </div>