implemented following users to receive (opt-in) email notifications when they publish an article.

articles.php

@@ -5,6 +5,7 @@ require_once 'functions/functions.php';
 include_once 'components/head.php';
 
 include_once 'functions/article_functions.php';
+include_once 'functions/account_functions.php';
 
 // UI Components
 foreach (glob('components/article/*.php') as $file)
@@ -22,49 +23,57 @@ if (isset($_POST['form_id'])) {
                 header('Location: articles.php?article_id=' . $_POST['article_id']);
             } else {
                 $id = create_article($_SESSION['user_id'], $_POST['title'], $_POST['excerpt'], (isset($_POST['tags']) ? $_POST['tags'] : []), $_POST['markdown']);
+                $emails = exec_stmt('SELECT email FROM user INNER JOIN follows ON user.user_id = follows.follower_user_id WHERE follows.following_user_id = ? AND follows.notify_user = 1', 'i', $_SESSION['user_id'])->fetch_assoc();
+                notify_users($emails, $_SESSION['username'], $id, $_POST['title'], $_POST['excerpt']);
                 header('Location: articles.php?article_id=' . $id);
             }
 
+            break;
+        case 'follow':
+            follow_user($_SESSION['user_id'], $_POST['author_id'], ($_POST['follow'] == 'email_notify' ? 1 : 0));
+            break;
+        case 'unfollow':
+            unfollow_user($_SESSION['user_id'], $_POST['author_id']);
             break;
     }
-} else {
+}
-    if (isset($_GET['view']))
-        $view = $_GET['view'];
-    else
-        $view = 'list';
 
-    switch ($view) {
+if (isset($_GET['view']))
-        case 'list':
+    $view = $_GET['view'];
-            echo article_list();
+else
-            break;
+    $view = 'list';
-        case 'filter':
+
-            if (isset($_GET['tag']))
+switch ($view) {
-                echo article_list(article_ids_by_tag($_GET['tag']));
+    case 'list':
-            else if (isset($_GET['author_id']))
+        echo article_list();
-                echo article_list(articles_ids_by_author($_GET['author_id']));
+        break;
-            break;
+    case 'filter':
-        case 'sort':
+        if (isset($_GET['tag']))
-            if (isset($_GET['sort']) && $_GET['sort'] == 'oldest')
+            echo article_list(article_ids_by_tag($_GET['tag']));
-                echo article_list(article_ids_by_oldest());
+        else if (isset($_GET['author_id']))
-            else if (isset($_GET['sort']) && $_GET['sort'] == 'newest')
+            echo article_list(articles_ids_by_author($_GET['author_id']));
-                echo article_list(article_ids_by_newest());
+        break;
-            break;
+    case 'sort':
-        case 'read':
+        if (isset($_GET['sort']) && $_GET['sort'] == 'oldest')
-            if (isset($_SESSION['user_id']) && isset($_GET['article_id'])) {
+            echo article_list(article_ids_by_oldest());
-                increment_read_counter($_GET['article_id']);
+        else if (isset($_GET['sort']) && $_GET['sort'] == 'newest')
-                echo article_page_from_markdown($_GET['article_id']);
+            echo article_list(article_ids_by_newest());
-            } else {
+        break;
-                $redirect = (isset($_GET['article_id']) ? 'articles.php?view=read&article_id=' . $_GET['article_id'] : '');
+    case 'read':
-                if ($redirect)
+        if (isset($_SESSION['user_id']) && isset($_GET['article_id'])) {
-                    header('Location: user.php?view=login&redirect=' . urlencode($redirect));
+            increment_read_counter($_GET['article_id']);
-                else
+            echo article_page_from_markdown($_GET['article_id']);
-                    header('Location: articles.php');
+        } else {
-            }
+            $redirect = (isset($_GET['article_id']) ? 'articles.php?view=read&article_id=' . $_GET['article_id'] : '');
-            break;
+            if ($redirect)
-        case 'compose':
+                header('Location: user.php?view=login&redirect=' . urlencode($redirect));
-            echo compose_view((isset($_GET['article_id']) ? $_GET['article_id'] : ''));
+            else
-            break;
+                header('Location: articles.php');
-    }
+        }
+        break;
+    case 'compose':
+        echo compose_view((isset($_GET['article_id']) ? $_GET['article_id'] : ''));
+        break;
 }
 
 if (($view == 'list' || $view == 'sort') && (isset($_SESSION['role_id']) && $_SESSION['role_id'] <= 3)) {

components/article/article.php

@@ -8,6 +8,7 @@ function article_page_from_markdown($article_id)
     $article = exec_stmt('SELECT * FROM article WHERE article_id = ?', 'i', $article_id)->fetch_assoc();
     $author = exec_stmt('SELECT user_id, username, profile_picture FROM user WHERE user_id = ?', 'i', $article['author_id'])->fetch_assoc();
     $markdown = read_file_one_string($_ENV['ARTICLES_FQ_PATH'] . $article_id . '/article.md');
+    $following = exec_stmt('SELECT follower_user_id, following_user_id FROM follows WHERE follower_user_id = ? AND following_user_id = ?', 'ii', $_SESSION['user_id'], $author['user_id'])->fetch_assoc();
 
     $parsedown = new Parsedown();
     $parsedown->setSafeMode(true);
@@ -21,10 +22,41 @@ function article_page_from_markdown($article_id)
                 ' . (isset($_SESSION['user_id']) && $_SESSION['user_id'] == $article['author_id'] ? '<a href="articles.php?view=compose&article_id=' . $article_id . '"><i class="nf nf-fa-edit"></i></a>' : '') . '
             </div>
             <div class="row">
-                <div class="col_right">
+                <div class="row">
-                    <h5>Written by <a href="user.php?action=view&user_id=' . $author['user_id'] . '">' . $author['username'] . '</a></h5>
+                    <div class="col_right">
-                    <p>Published on ' . $article['published_at'] . '<br>
+                        <h5>Written by <a href="user.php?view=display&user_id=' . $author['user_id'] . '">' . $author['username'] . '</a></h5>
-                    Lasted edited on ' . $article['updated_at'] . '</p>
+                        <p>Published on ' . $article['published_at'] . '<br>
+                        Lasted edited on ' . $article['updated_at'] . '</p>
+                    </div>
+    ';
+
+    if ($_SESSION['user_id'] != $author['user_id'] && !$following) {
+        $html .= '
+                    <div class="dropdown">
+                        <span>Follow</span>
+                        <div class="dropdown_content">
+                            <form method="post">
+                                <input type="hidden" name="form_id" value="follow">
+                                <input type="hidden" name="author_id" value="' . $author['user_id'] . '">
+                                <button name="follow" value="no_notify" class="button"><i class="nf nf-md-bell_cancel"></i></button>
+                                <button name="follow" value="email_notify" class="button"><i class="nf nf-cod-mail"></i></button>
+                            </form>
+                        </div>
+                    </div>
+        ';
+    } else if ($following) {
+        $html .= '
+            <div class="margin_right">
+                <form method="post">
+                    <input type="hidden" name="form_id" value="unfollow">
+                    <input type="hidden" name="author_id" value="' . $author['user_id'] . '">
+                    <input type="submit" value="Unfollow">
+                </form>
+            </div>
+        ';
+    }
+
+    $html .= '
                 </div>
                 <div class="card_pic_box">
                     <img src="' . $_ENV['PROFILE_IMAGES_PQ_PATH'] . $author['profile_picture'] . '" class="card_profile_picture" />

components/article/card.php

@@ -27,7 +27,7 @@ function article_card($article_id)
                 <h4>' . $article['title'] . '</h4>
                 <div class="card_info_box">
                     <div class="col-right">
-                        <a href="user.php?action=view&user_id=' . $author['user_id'] . '">Written by: ' . $author['username'] . '</a>
+                        <a href="user.php?view=display&user_id=' . $author['user_id'] . '">Written by: ' . $author['username'] . '</a>
                         <small>Published: ' . $article['published_at'] . '</small>
                         <small>Updated: ' . $article['updated_at'] . '</small>
                     </div>

components/user/user_view.php

@@ -1,14 +1,50 @@
 <?php
+include_once 'components/article/card.php';
+
 function user_view($user_id)
 {
+    if ($_SESSION['user_id'] != $user_id)
+        $following = exec_stmt('SELECT follower_user_id, following_user_id FROM follows WHERE follower_user_id = ? AND following_user_id = ?', 'ii', $_SESSION['user_id'], $user_id)->fetch_assoc();
     $user = exec_stmt('SELECT user_id, username, email, role_id, created_at, last_active, is_active, profile_picture FROM user WHERE user_id = ?', 'i', $user_id)->fetch_assoc();
+
     if ($user == null)
-        header('Location: articles.php');
+        header('Location: articles.php?view=sort&sort=newest');
 
     $view = '
     <div class="user_view">
         <div class="row">
-            <h1>' . $user['username'] . '</h1>
+            <div class="row">
+                <h1>' . $user['username'] . '</h1>
+    ';
+
+    if ($_SESSION['user_id'] != $user_id && !$following) {
+        $view .= '
+                    <div class="dropdown">
+                        <span>Follow</span>
+                        <div class="dropdown_content">
+                            <form method="post">
+                                <input type="hidden" name="form_id" value="follow">
+                                <input type="hidden" name="author_id" value="' . $user_id . '">
+                                <button name="follow" value="no_notify" class="button"><i class="nf nf-md-bell_cancel"></i></button>
+                                <button name="follow" value="email_notify" class="button"><i class="nf nf-cod-mail"></i></button>
+                            </form>
+                        </div>
+                    </div>
+        ';
+    } else if ($following) {
+        $view .= '
+            <div class="margin_right">
+                <form method="post">
+                    <input type="hidden" name="form_id" value="unfollow">
+                    <input type="hidden" name="author_id" value="' . $user_id . '">
+                    <input type="submit" value="Unfollow">
+                </form>
+            </div>
+        ';
+    }
+
+    $view .= '
+            </div>
             <div class="card_pic_box">
                 <img src="' . $_ENV['PROFILE_IMAGES_PQ_PATH'] . $user['profile_picture'] . '" class="profile_picture" />
             </div>

css/base.css

@@ -31,7 +31,8 @@ a,
 .modal_button,
 th,
 td,
-li {
+li,
+span {
   font-family: 'Hack Nerd Font Mono', Hack, sans-serif;
   padding: 0;
   margin: 0;
@@ -65,7 +66,8 @@ a,
 label,
 li,
 .modal_button,
-.button {
+.button,
+span {
   font-size: 1vw;
 }
 
@@ -285,10 +287,6 @@ table tr td label {
   border: 3px solid orange;
 }
 
-.button:hover {
-  box-shadow: 0 2px 4px 0 rgba(255, 165, 0, 0.3), 0 3px 8px 0 rgba(255, 165, 0, 0.7);
-}
-
 .narrow {
   width: 20%;
 }
@@ -301,10 +299,6 @@ table tr td label {
   text-decoration: none;
 }
 
-.tag:hover {
-  box-shadow: 0 2px 4px 0 rgba(255, 165, 0, 0.3), 0 3px 8px 0 rgba(255, 165, 0, 0.7);
-}
-
 .tag_row {}
 
 .tag_box {
@@ -383,7 +377,6 @@ textarea:focus,
 input:hover,
 textarea:hover {
   border: 3px solid orange;
-  box-shadow: 0 2px 4px 0 rgba(255, 165, 0, 0.3), 0 3px 8px 0 rgba(255, 165, 0, 0.7);
   outline: none;
 }
 
@@ -734,6 +727,37 @@ hr {
   border-radius: 9px;
 }
 
+.dropdown {
+  position: relative;
+  display: block;
+  margin-right: 15px;
+  padding: 15px;
+  border-radius: 9px;
+}
+
+.dropdown_content {
+  display: none;
+  position: absolute;
+  min-width: 50px;
+  padding: 15px;
+  z-index: 2;
+}
+
+.dropdown:hover .dropdown_content {
+  display: block;
+  margin-left: -15px;
+  margin-top: 15px;
+  border-radius: 12px;
+}
+
+.dropdown_content form * {
+  margin-top: 5px;
+  margin-bottom: 5px;
+}
+
+.margin_right {
+  margin-right: 15px;
+}
 
 @media screen and (max-width: 992px) {
   body {
@@ -772,7 +796,8 @@ hr {
   ul li a,
   ol li a,
   .modal_button,
-  .button {
+  .button,
+  span {
     font-size: 2vw;
   }
 

css/dark.css

@@ -13,7 +13,8 @@ h4,
 h5,
 p,
 small,
-label {
+label,
+span {
   color: white;
 }
 
@@ -54,9 +55,9 @@ table tr {
   color: white;
 }
 
-.button:hover {
+.button:hover,
-  color: black;
+.button:hover i {
-  background-color: white;
+  color: orange;
 }
 
 .tag {
@@ -139,6 +140,15 @@ select:-webkit-autofill {
   border: 2px solid orange;
 }
 
+.dropdown {
+  border: 2px solid white;
+}
+
+.dropdown_content {
+  background-color: black;
+  border: 2px solid white;
+}
+
 @media screen and (max-width: 992px) {
   nav {
     border-bottom: none;

css/light.css

@@ -13,7 +13,8 @@ h4,
 h5,
 p,
 small,
-label {
+label,
+span {
   color: black;
 }
 
@@ -54,9 +55,9 @@ table tr {
   color: black;
 }
 
-.button:hover {
+.button:hover,
-  color: white;
+.button:hover * {
-  background-color: black;
+  color: orange;
 }
 
 .tag {
@@ -139,6 +140,15 @@ select:-webkit-autofill {
   border: 2px solid orange;
 }
 
+.dropdown {
+  border: 2px solid black;
+}
+
+.dropdown_content {
+  background-color: white;
+  border: 2px solid black;
+}
+
 @media screen and (max-width: 992px) {
   nav {
     border-bottom: none;

functions/account_functions.php

@@ -4,6 +4,16 @@ require_once 'article_functions.php';
 
 use Postmark\PostmarkClient;
 
+function follow_user($follower_user_id, $following_user_id, $notify)
+{
+    exec_stmt('INSERT INTO follows (follower_user_id, following_user_id, notify_user) VALUES (?, ?, ?)', 'iii', $follower_user_id, $following_user_id, $notify);
+}
+
+function unfollow_user($follower_user_id, $following_user_id)
+{
+    exec_stmt('DELETE FROM follows WHERE follower_user_id = ? AND following_user_id = ?', 'ii', $follower_user_id, $following_user_id);
+}
+
 function user_id_exists($user_id)
 {
     $result = exec_stmt('SELECT user_id FROM user WHERE user_id = ?', 'i', $user_id)->fetch_assoc();

functions/functions.php

@@ -1,17 +1,36 @@
 <?php
+include_once 'functions/init.php';
 
-if (!empty($_FILES['upload'])) {
+use Postmark\PostmarkClient;
-    require_once '../vendor/autoload.php';
 
-    // Load environment variables.
+if (!empty($_FILES['upload']))
-    $dotenv = Dotenv\Dotenv::createImmutable(__DIR__ . '/../');
-    $dotenv->safeLoad();
     upload($_FILES['upload'], $_ENV['UPLOAD_TMP_FQ_PATH'], isset($_POST['filename']) ? $_POST['filename'] : null);
+
+function notify_users($emails, $auther_username, $article_id, $article_title, $excerpt)
+{
+    foreach ($emails as $email) {
+        $email_html = '
+            <h1>' . $article_title . '</h1>
+            <p>An author you follow just published a new article! Read it <a href="https://vintagecoding.net/articles.php?view=read&article_id=' . $article_id . '" target="_blank">here</a></p>
+            <p><strong>Here is a snippet from the article!</strong></p>
+            <p>' . $excerpt . '</p>
+        ';
+
+        $client = new PostmarkClient($_ENV['POSTMARK_API_TOKEN']);
+
+        $client->sendEmail(
+            'mailer@joshashton.dev',
+            $email,
+            $auther_username . ' just published a new article! - vintagecoding.net',
+            $email_html
+        );
+    }
 }
 
 function delete_dir($dir)
 {
-    if (!is_dir($dir)) return false;
+    if (!is_dir($dir))
+        return false;
 
     if (substr($dir, strlen($dir) - 1, 1) != '/') {
         $dir .= '/';
@@ -28,7 +47,8 @@ function delete_dir($dir)
 
 function delete_file($file)
 {
-    if (!file_exists($file)) return false;
+    if (!file_exists($file))
+        return false;
 
     unlink($file);
 }
@@ -54,7 +74,7 @@ function upload($input, $dest_dir, $filename = null)
 
             break;
         default:
-            # code...
+            // code...
             break;
     }
 
@@ -66,7 +86,7 @@ function upload($input, $dest_dir, $filename = null)
 
 function crop_image($img_path, $x, $y, $height, $width)
 {
-    //$dest = $_ENV['UPLOAD_TMP_FQ_PATH'];
+    // $dest = $_ENV['UPLOAD_TMP_FQ_PATH'];
     $dest = '/tmp/';
     // Get the image type
     $imageType = exif_imagetype($img_path);
@@ -80,11 +100,11 @@ function crop_image($img_path, $x, $y, $height, $width)
             $sourceImage = imagecreatefrompng($img_path);
             break;
         default:
-            return false; // Unsupported image type
+            return false;  // Unsupported image type
     }
 
     if (!$sourceImage)
-        return false; // Failed to create image resource
+        return false;  // Failed to create image resource
 
     // Create a new image resource for the cropped image
     $croppedImage = imagecreatetruecolor($width, $height);
@@ -109,7 +129,7 @@ function crop_image($img_path, $x, $y, $height, $width)
     imagedestroy($sourceImage);
     imagedestroy($croppedImage);
 
-    return true; // Cropping successful
+    return true;  // Cropping successful
 }
 
 /*
@@ -132,7 +152,7 @@ function extract_content_from_tag($string, $start, $end)
 {
     $ini = strpos($string, $start);
     if ($ini != 0)
-        return "nope";
+        return 'nope';
 
     $ini += strlen($start);
     $len = strpos($string, $end, $ini) - $ini;
@@ -151,9 +171,7 @@ function check_csv_upload($target)
 
 function pretty_dump($arr)
 {
-    echo '
+    echo '<pre>';
-    <pre>
+    print_r($arr);
-        ' . print_r($arr) . '
+    echo '</pre>';
-    </pre>
-    ';
 }

scripts/init.sql

@@ -60,6 +60,16 @@ CREATE TABLE article_tags (
   FOREIGN KEY (tag_id) REFERENCES tags(tag_id)
 );
 
+CREATE TABLE follows (
+    follower_user_id INT NOT NULL,
+    following_user_id INT NOT NULL,
+    notify_user BOOLEAN DEFAULT FALSE,
+    followed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (follower_user_id, following_user_id),
+    FOREIGN KEY (follower_user_id) REFERENCES user(user_id) ON DELETE CASCADE,
+    FOREIGN KEY (following_user_id) REFERENCES user(user_id) ON DELETE CASCADE
+);
+
 INSERT INTO roles (role)
   VALUES ('owner'), ('admin'), ('contributor'), ('reader');
 

user.php

@@ -82,6 +82,12 @@ if (isset($_POST['form_id'])) {
                 $_POST['delete_verify_password']
             );
 
+            break;
+        case 'follow':
+            follow_user($_SESSION['user_id'], $_POST['author_id'], ($_POST['follow'] == 'email_notify' ? 1 : 0));
+            break;
+        case 'unfollow':
+            unfollow_user($_SESSION['user_id'], $_POST['author_id']);
             break;
     }
     echo $msg;