add reply to a comment system that using jquery and php - php

Question

I was trying to create a commenting system like that uses facebook. I use php and jquery. My code works perfect. All I want is just to add a reply system in it. Any idea how to do this?
This is my main page: wall.php
<script>
$(document).ready(function(){
$("#comment_process").click(function(){
if($("#comment_text").val() != ""){
$.post("comments.php?action=post", { comment: $("#comment_text").val() }, function(data) {
$(".comments").html(data);
$("#comment_text").val("");
});
}
});
});
</script>
<div class="comment_container">
<div class="comment_form">
<textarea id="comment_text" ></textarea>
<input type="button" id="comment_process" value="Post"/>
</div>
</div>
<div class="comments"> <?php include_once("comments.php");?> </div>
?>
and this is comments.php
<?php
function getComments(){
$comments = "";
// use desc order by date in order to display comments by date
$sql = mysql_query("SELECT * FROM comments ORDER BY comment_date DESC ") or die (mysql_error());
if(mysql_num_rows($sql) == 0){
$comments = " <div class='each_comment'> There are no comments ...</div> ";
}else{
while ($row= mysql_fetch_assoc($sql)){
$comments .= "Says : <div class='each_comment'> <small><em> ".$row['comment_date']." </em></small><br />".$row['comment']."</div> </br>";
}
}
return $comments;
}
function postComments($comment){
$comment = mysql_real_escape_string(strip_tags($comment));
$sql = mysql_query(" INSERT INTO `comments` (comment, comment_date) VALUES ('".$comment."', now()) ");
return true;
}
if((isset($_GET['action'])) && ($_GET['action'] == "post")) {
postComments($_POST['comment']);
}
echo getComments();
?>

Answer 1

Orbling has it right. Let me show you what I did for my blog site that I am working on in ASP.NET MVC and maybe it will others in the future.
I have two classes named Article and Comment and they would have the following properties in php from what I remember. A little rusty on my php
class Article {
public $article_id;
public $user_id;
public $article_date;
//... more properties, ctors, methods
}
class Comment {
public $comment_id;
public $article_id;
public $isRoot;
public $parent_id;
public $comment_date;
public $content;
//... more properties, ctors, methods
}
Then I would user similar to what you constructed:
function getComments($article_id){
$str = "";
// This should put all the comment in order by date but we still have to separate the //comments from the replies so we will add an additional nest foreach loop following an if //statement inside the main foreach loop. What will happen is the newest/oldest comment //will be the first one appended to the string and then it will go to the inner foreach //loop to see if the $parent_id = $comment_id and if it does it will append to string.
//I have a different div class for replies so they are indented. This may not be the most //practical way, but considering that most articles are going to have less that a 1000 //comments if your lucky this wont be too bad.
$q = $this->db->query("SELECT * FROM comments WHERE article_id = $article_id ORDER BY comment_date DESC") or die (mysql_error());
if($q->num_rows() > 0):
foreach($q->result() as $row):
if($row->isRoot && $row->ParentId = null):
// here you will append to the $str where you will create a div container //for each comment which is a root comment. I included a user avatar, user link, date //create, content, and on the bottom of my div I have an <span>expand replies</span> and a //<span>reply<span> where I use JQuery to toggle the replies on and off etc.
// Now I do the same thing here as I will cycle through $q to find the //comments with the parent_id equal to the comment_id of this $row
//they will already be ordered by date. Cool thing is you could create an array of the reply and change the order so maybe you want newest comments on top but oldest replies on //top or I should say below the parent comment
foreach($q->result() as $row2):
if($row->comment_id = $row2->parent_id)
// do the same thing except html format for reply (eg: indent div)
endif;
endforeach;
endforeach;
}
else:
$str = "<div class='each_comment'> There are no comments ...</div> ";
endif;
echo htmlentities($str);
}
Then you will have to use some JQuery/Javascript as Orbling suggests: show(); hide(); replies and use a function such as slideDown(parent_id); once the reply button is hit where a <div> container appears below its parent comment.