edit_posts.php

<?php
$pagenum = 1;
if(!empty($_GET['pagenum'])) {
    $pagenum = filter_input(INPUT_GET, 'pagenum', FILTER_VALIDATE_INT);
    if(false === $pagenum) {
        $pagenum = 1;
    }
}
if (isset($_GET['id'])) {
    $post_id = $_GET['id'];
}
?>

<h1>Edit posts</h1>

<?php

if (!empty($_GET['action'])) {
    ?>
    <button onclick="window.location='admin.php?page=edit_posts';">Go back</button>
    <?php
} else {
    ?>
    <button onclick="window.location='admin.php';">Go back</button>
    <?php
}

if ($_GET['action'] == 'edit') {
    $post = new Post($post_id);

    // Save details on submit
    if (isset($_POST['submit'])) {
        $title = $_POST['title'];
        $content = $_POST['content'];
        $result = $post->saveDetails($title, $content);
        if ($result == true) {
            echo '<script>alert("The details have been saved.");</script>';
            echo '<script>history.back(1);</script>';
        } else {
            echo '<script>alert("Something went wrong, please try again.");</script>';
            echo '<script>history.back(1);</script>';
        }
    }

    $post->getPost();
    ?>

    <div class="edit_post">
        <form action="" method="post">
            <p><label>Title</label><br><input type="text" value="<?php echo $post->getTitle(); ?>" name="title"></p>
            <p><label>Content</label><br><textarea class="tinymce" name="content"><?php echo
                    $post->getContent();
            ?></textarea></p>
            <p><input type="submit" name="submit" value="Save"></p>
        </form>
    </div>

    <?php
} else if ($_GET['action'] == 'add_post') {

    // Save details on submit
    if (isset($_POST['addPost_submit'])) {
        $admin = new Admin;
        $title = $_POST['title'];
        $content = $_POST['content'];
        $result = $admin->addPost($title, $content);
        if ($result == true) {
            echo '<script>alert("The details have been saved.");</script>';
            echo '<script>window.location="admin.php?page=edit_posts";</script>';
        } else {
            echo '<script>alert("Something went wrong, please try again.");</script>';
            echo '<script>history.back(1);</script>';
        }
    }

    ?>

    <div class="add_post">
        <form action="" method="post">
            <p><label>Title</label><br><input type="text" name="title"></p>
            <p><label>Content</label><br><textarea class="tinymce" name="content"></textarea></p>
            <p><input type="submit" name="addPost_submit" value="Save"></p>
            <?php echo $admin->getPosterId(); ?>
        </form>
    </div>

    <?php
} else if ($_GET['action'] == 'delete') {
    $del_id = $_GET['id'];
    $post = new Post($del_id);
    $result = $post->deletePost();
    if ($result == true) {
        echo '<script>history.back(1);</script>';
    } else {
        echo '<script>alert("Something went wrong, please try again.");</script>';
        echo '<script>history.back(1);</script>';
    }
} else {
    ?>
    <button onclick="window.location='admin.php?page=edit_posts&action=add_post';">Add a new post</button>

    <?php
    $admin = new Admin();
    $admin->showPosts($pagenum);
}
?>