add pagination

src/main.rs

@@ -24,6 +24,7 @@ use std::vec::Vec;
 use tera::Context;
 
 const TITLES: [&str; 4] = ["/* {} */", "# {}", "// {}", "<!-- {} -->"];
+const MAX_POSTS_PER_PAGE: i64 = 20;
 
 fn establish_connection() -> PgConnection {
     dotenv().ok();
@@ -32,21 +33,29 @@ fn establish_connection() -> PgConnection {
     PgConnection::establish(&database_url).expect(&format!("Error connecting to {}", database_url))
 }
 
-pub fn get_posts() -> Vec<Post> {
+fn get_posts(page: i64) -> (Vec<Post>, i64) {
     use schema::posts::dsl::*;
 
     let connection = establish_connection();
-    posts
+    let visible_posts = posts
         .filter(published.eq(true))
-        .limit(20)
+        .limit(MAX_POSTS_PER_PAGE)
+        .offset(MAX_POSTS_PER_PAGE * (page - 1))
         .load::<Post>(&connection)
-        .expect("Error loading posts")
+        .expect("Error loading posts");
+
+    let number_of_posts: i64 = posts
+        .filter(published.eq(true))
+        .count()
+        .get_result(&connection)
+        .expect("Error counting the posts");
+
+    (visible_posts, number_of_posts)
 }
 
 #[get("/?<page>")]
 fn index(page: Option<i8>) -> Template {
-    let page = page.unwrap_or_else(|| 0);
-    println!("{}", page);
+    let page = page.unwrap_or_else(|| 1);
 
     let mut context = Context::new();
 
@@ -54,8 +63,14 @@ fn index(page: Option<i8>) -> Template {
     let title_fmt = TITLES[rng.gen_range(0, TITLES.len())];
     let title = str::replace(title_fmt, "{}", "CódigoComentado");
 
+    let (posts, n_posts) = get_posts(page as i64);
+
+    let total_pages = (n_posts as f64 / MAX_POSTS_PER_PAGE as f64).ceil() as i64;
+
     context.insert("title", &title);
-    context.insert("posts", &get_posts());
+    context.insert("posts", &posts);
+    context.insert("total_pages", &total_pages);
+    context.insert("actual_page", &page);
     Template::render("index", context)
 }
 

static/css/index.css

@@ -45,7 +45,14 @@ article figure img {
     grid-area: info;
 }
 
-article strong {
+strong {
     font-family: monospace;
     font-size: 10px;
 }
+
+div.pagination {
+    margin-top: 50px;
+    width: auto;
+    height: 3em;
+    text-align: center;
+}

templates/index.html.tera

@@ -20,4 +20,14 @@
         </article>
     </a>
     {% endfor %}
+
+    {# Pages #}
+    <div class="pagination">
+    <strong>Pages:</strong>
+    [
+    {% for n in range(start=1, end=total_pages+1) %}
+            <a {% if actual_page != n %} href="?page={{ n }}"{% endif %}>página {{ n }}</a>{% if total_pages != n %}, {% endif %}
+    {% endfor %}
+    ]
+    </div>
 {% endblock content %}