Nested comments pagination will not work for children comments - php

Question

Hard limit is working thanks to Luuk, but pagination is still not working.
Based on my previous question, I am currently building comments system for a blog and want to make it reddit like.
I am currently using the nested comments by http://www.jongales.com/blog/2009/01/27/php-class-for-threaded-comments/
class Threaded_comments
{
public $parents = array();
public $children = array();
/**
* #param array $comments
*/
function __construct($comments)
{
foreach ($comments as $comment)
{
if ($comment['parent_id'] === NULL)
{
$this->parents[$comment['id']][] = $comment;
}
else
{
$this->children[$comment['parent_id']][] = $comment;
}
}
}
/**
* #param array $comment
* #param int $depth
*/
private function format_comment($comment, $depth)
{
for ($depth; $depth > 0; $depth--)
{
echo "\t";
}
echo $comment['text'];
echo "\n";
}
/**
* #param array $comment
* #param int $depth
*/
private function print_parent($comment, $depth = 0)
{
foreach ($comment as $c)
{
$this->format_comment($c, $depth);
if (isset($this->children[$c['id']]))
{
$this->print_parent($this->children[$c['id']], $depth + 1);
}
}
}
public function print_comments()
{
foreach ($this->parents as $c)
{
$this->print_parent($c);
}
}
}
Here’s the example usage with the data provided as an array. Remember that if your data is in another format you’ll have to modify the class.
$comments = array( array('id'=>1, 'parent_id'=>NULL, 'text'=>'Parent'),
array('id'=>2, 'parent_id'=>1, 'text'=>'Child'),
array('id'=>3, 'parent_id'=>2, 'text'=>'Child Third level'),
array('id'=>4, 'parent_id'=>NULL, 'text'=>'Second Parent'),
array('id'=>5, 'parent_id'=>4, 'text'=>'Second Child')
);
$threaded_comments = new Threaded_comments($comments);
$threaded_comments->print_comments();
Example Output:
Parent
Child
Child Third level
Second Parent
Second Child
I have set the depth limit, created the html output and everything, but the problem is pagination. Whenever I try to do a pagination via offset limit, it disrupts the child comments and the structure because the next page does not have original parent where to attach children and such.
For example:
select count(*) as found_comments from comments where blog_post = 1 and parent_id is null;
result = 20; // lets say its 20 parent comments limit from query above.
$query = "select * from comments where blog_post = 1 LIMIT 0,20";
$comments = [];
foreach ($query as $row)
{
$comments[] = [
'id' => $row['id'],
'parent_id' => $row['parent_id'],
'text' = $row['text'],
'added' => $row['added']];
}
$threaded_comments = new Threaded_comments($comments);
$threaded_comments->print_comments();
This code will limit both parent and children comments, but I need to set it to limit only parents, so 20 parents per page.
If I set in count query WHERE blog_post = 1 AND parent_id = 0
it will count parents only, but will cut out children comments when 20 quota is reached in $comments query.
It's really headache to find a way to do this. Any help is appreciated.

Answer 1

An example of how to change your code to only print 2 parents:
public function print_comments($count =2)
{
foreach ($this->parents as $c)
{
$this->print_parent($c);
$count--;
if($count == 0) exit;
}
}