From f0e911a79c429bd10908071ff1ebf3ee494054a8 Mon Sep 17 00:00:00 2001
From: zPlus <->
Date: Sat, 19 Mar 2016 08:56:28 +0100
Subject: [PATCH] Add pagination to homepage results

---
 database.php        | 53 ++++++++++++++++++++++++++++++++++++++-------
 index.php           | 24 +++++++++++++++-----
 template/index.twig |  5 +++++
 3 files changed, 68 insertions(+), 14 deletions(-)

diff --git a/database.php b/database.php
index c12b9e5d..79619677 100644
--- a/database.php
+++ b/database.php
@@ -4,7 +4,12 @@ require_once 'config.php';
 
 class Database
 {
-    protected $database;
+    
+    /***** STATIC *****/
+    
+    
+    // How many items to display in homepage
+    const HOMEPAGE_RESULTS = 50;
     
     protected static function get_random_string ($length = 10) {
         $characters = '0123456789abcdefghijklmnopqrstuvwxyz';
@@ -18,6 +23,13 @@ class Database
         return $hash_id;
     }
     
+    
+    /***** INSTANCE *****/
+    
+    
+    // Reference to a database connection
+    protected $database;
+    
     function __construct ()
     {
         $this->database = NULL;
@@ -27,7 +39,14 @@ class Database
     {
         try {
             
-            $this->database = new PDO (Config::$DATABASE['dsn'], Config::$DATABASE['username'], Config::$DATABASE['password']);
+            $this->database = new PDO (
+                Config::$DATABASE['dsn'],
+                Config::$DATABASE['username'],
+                Config::$DATABASE['password']);
+                
+            $this->database->setAttribute (
+                PDO::ATTR_ERRMODE,
+                PDO::ERRMODE_EXCEPTION);
             
             return true;
             
@@ -317,19 +336,28 @@ class Database
     /**
      * Get posts by rating (for homepage)
      */
-    function get_hot_posts ()
+    function get_hot_posts ($page = 0)
     {
         $submissions = array();
+        $page = intval ($page);
         
         if (is_null ($this->database))
             return $submissions;
         
-        $query = $this->database->query (
+        if ($page < 0)
+            $page = 0;
+        
+        $query = $this->database->prepare (
             'SELECT P.*, U.`username`' .
             'FROM `post` AS P ' .
             'JOIN `user` AS U ON P.`userId` = U.`id`' .
             'ORDER BY P.`dateCreated` DESC, P.`vote` DESC, P.`commentsCount` DESC ' .
-            'LIMIT 50');
+            'LIMIT :limit OFFSET :offset');
+        
+        $query->bindValue (':limit', Database::HOMEPAGE_RESULTS, PDO::PARAM_INT);
+        $query->bindValue (':offset', $page * Database::HOMEPAGE_RESULTS, PDO::PARAM_INT);
+        
+        $query->execute ();
         
         $submissions = $query->fetchAll (PDO::FETCH_ASSOC);
         
@@ -339,19 +367,28 @@ class Database
     /**
      * Get posts by date (for homepage)
      */
-    function get_new_posts ()
+    function get_new_posts ($page = 0)
     {
         $submissions = array();
+        $page = intval ($page);
         
         if (is_null ($this->database))
             return $submissions;
         
-        $query = $this->database->query(
+        if ($page < 0)
+            $page = 0;
+        
+        $query = $this->database->prepare (
             'SELECT P.*, U.`username`' .
             'FROM `post` AS P ' .
             'JOIN `user` AS U ON P.`userId` = U.`id`' .
             'ORDER BY P.`created` DESC ' .
-            'LIMIT 50');
+            'LIMIT :limit OFFSET :offset');
+        
+        $query->bindValue (':limit', Database::HOMEPAGE_RESULTS, PDO::PARAM_INT);
+        $query->bindValue (':offset', $page * Database::HOMEPAGE_RESULTS, PDO::PARAM_INT);
+        
+        $query->execute ();
             
         $submissions = $query->fetchAll (PDO::FETCH_ASSOC);
         
diff --git a/index.php b/index.php
index 4265120d..ee353143 100644
--- a/index.php
+++ b/index.php
@@ -6,17 +6,28 @@ require_once 'date.php';
 require_once 'twig.php';
 
 // Open database connection
-$db = new Database();
-$db->connect();
+$db = new Database ();
+$db->connect ();
+
+// Pagination. What page are we in?
+if (isset ($_GET['page']))
+{
+    $page = intval ($_GET['page']);
+    
+    if ($page < 0)
+        $page = 0;
+} else {
+    $page = 0;
+}
 
 // Retrieve list of posts
 if (isset ($_GET['new']))
-    $posts = $db->get_new_posts();
+    $posts = $db->get_new_posts ($page);
 else
-    $posts = $db->get_hot_posts();
+    $posts = $db->get_hot_posts ($page);
 
 // Retrieve a list of user votes for the posts
-$IDs = array();
+$IDs = array ();
 
 foreach ($posts as $post)
     $IDs[] = $post['id'];
@@ -28,4 +39,5 @@ echo $twig->render (
     'index.twig',
     array(
         'posts' => $posts,
-        'votes' => $votes));
\ No newline at end of file
+        'votes' => $votes,
+        'page'  => $page));
\ No newline at end of file
diff --git a/template/index.twig b/template/index.twig
index 82ee1759..e2b0f3e7 100644
--- a/template/index.twig
+++ b/template/index.twig
@@ -37,6 +37,11 @@
         
     {% endfor %}
     
+    <div class="more">
+        <a href="?page={{ page + 1 }}" class="btn btn-sm btn-danger">
+            More <span style="margin-left: 1em">▸</span>
+        </a>
+    </div>
 </div>
 
 {% include 'footer.twig' %}