php code for comment system

1// This is a single-line comment
2
3# This is also a single-line comment
4
5/*
6This is a multiple-lines comment block
7that spans over multiple
8lines
9*/

1<?php
2// This is a single-line comment
3
4# This is also a single-line comment
5  
6/*
7This is a multiple-lines comment block
8that spans over multiple
9lines
10*/
11  
12// You can also use comments to leave out parts of a code line
13$x = 5 /* + 15 */ + 5;
14echo $x;
15?>

1//...
2// If the user clicked submit on comment form...
3if (isset($_POST['comment_posted'])) {
4	global $db;
5	// grab the comment that was submitted through Ajax call
6	$comment_text = $_POST['comment_text'];
7	// insert comment into database
8	$sql = "INSERT INTO comments (post_id, user_id, body, created_at, updated_at) VALUES (1, " . $user_id . ", '$comment_text', now(), null)";
9	$result = mysqli_query($db, $sql);
10	// Query same comment from database to send back to be displayed
11	$inserted_id = $db->insert_id;
12	$res = mysqli_query($db, "SELECT * FROM comments WHERE id=$inserted_id");
13	$inserted_comment = mysqli_fetch_assoc($res);
14	// if insert was successful, get that same comment from the database and return it
15	if ($result) {
16		$comment = "<div class='comment clearfix'>
17					<img src='profile.png' alt='' class='profile_pic'>
18					<div class='comment-details'>
19						<span class='comment-name'>" . getUsernameById($inserted_comment['user_id']) . "</span>
20						<span class='comment-date'>" . date('F j, Y ', strtotime($inserted_comment['created_at'])) . "</span>
21						<p>" . $inserted_comment['body'] . "</p>
22						<a class='reply-btn' href='#' data-id='" . $inserted_comment['id'] . "'>reply</a>
23					</div>
24					<!-- reply form -->
25					<form action='post_details.php' class='reply_form clearfix' id='comment_reply_form_" . $inserted_comment['id'] . "' data-id='" . $inserted_comment['id'] . "'>
26						<textarea class='form-control' name='reply_text' id='reply_text' cols='30' rows='2'></textarea>
27						<button class='btn btn-primary btn-xs pull-right submit-reply'>Submit reply</button>
28					</form>
29				</div>";
30		$comment_info = array(
31			'comment' => $comment,
32			'comments_count' => getCommentsCountByPostId(1)
33		);
34		echo json_encode($comment_info);
35		exit();
36	} else {
37		echo "error";
38		exit();
39	}
40}
41// If the user clicked submit on reply form...
42if (isset($_POST['reply_posted'])) {
43	global $db;
44	// grab the reply that was submitted through Ajax call
45	$reply_text = $_POST['reply_text']; 
46	$comment_id = $_POST['comment_id']; 
47	// insert reply into database
48	$sql = "INSERT INTO replies (user_id, comment_id, body, created_at, updated_at) VALUES (" . $user_id . ", $comment_id, '$reply_text', now(), null)";
49	$result = mysqli_query($db, $sql);
50	$inserted_id = $db->insert_id;
51	$res = mysqli_query($db, "SELECT * FROM replies WHERE id=$inserted_id");
52	$inserted_reply = mysqli_fetch_assoc($res);
53	// if insert was successful, get that same reply from the database and return it
54	if ($result) {
55		$reply = "<div class='comment reply clearfix'>
56					<img src='profile.png' alt='' class='profile_pic'>
57					<div class='comment-details'>
58						<span class='comment-name'>" . getUsernameById($inserted_reply['user_id']) . "</span>
59						<span class='comment-date'>" . date('F j, Y ', strtotime($inserted_reply['created_at'])) . "</span>
60						<p>" . $inserted_reply['body'] . "</p>
61						<a class='reply-btn' href='#'>reply</a>
62					</div>
63				</div>";
64		echo $reply;
65		exit();
66	} else {
67		echo "error";
68		exit();
69	}
70}

1$(document).ready(function(){
2	// When user clicks on submit comment to add comment under post
3	$(document).on('click', '#submit_comment', function(e) {
4		e.preventDefault();
5		var comment_text = $('#comment_text').val();
6		var url = $('#comment_form').attr('action');
7		// Stop executing if not value is entered
8		if (comment_text === "" ) return;
9		$.ajax({
10			url: url,
11			type: "POST",
12			data: {
13				comment_text: comment_text,
14				comment_posted: 1
15			},
16			success: function(data){
17				var response = JSON.parse(data);
18				if (data === "error") {
19					alert('There was an error adding comment. Please try again');
20				} else {
21					$('#comments-wrapper').prepend(response.comment)
22					$('#comments_count').text(response.comments_count); 
23					$('#comment_text').val('');
24				}
25			}
26		});
27	});
28	// When user clicks on submit reply to add reply under comment
29	$(document).on('click', '.reply-btn', function(e){
30		e.preventDefault();
31		// Get the comment id from the reply button's data-id attribute
32		var comment_id = $(this).data('id');
33		// show/hide the appropriate reply form (from the reply-btn (this), go to the parent element (comment-details)
34		// and then its siblings which is a form element with id comment_reply_form_ + comment_id)
35		$(this).parent().siblings('form#comment_reply_form_' + comment_id).toggle(500);
36		$(document).on('click', '.submit-reply', function(e){
37			e.preventDefault();
38			// elements
39			var reply_textarea = $(this).siblings('textarea'); // reply textarea element
40			var reply_text = $(this).siblings('textarea').val();
41			var url = $(this).parent().attr('action');
42			$.ajax({
43				url: url,
44				type: "POST",
45				data: {
46					comment_id: comment_id,
47					reply_text: reply_text,
48					reply_posted: 1
49				},
50				success: function(data){
51					if (data === "error") {
52						alert('There was an error adding reply. Please try again');
53					} else {
54						$('.replies_wrapper_' + comment_id).append(data);
55						reply_textarea.val('');
56					}
57				}
58			});
59		});
60	});
61});