Migrating pagination code from PHP 7 to PHP 8

[fgm]

I'm using this snippet to paginate a static blog generator but, although it works fine in PHP 7.4, it doesn't work in PHP 8.1. This is the most complex part of the code I use and I'm lost, so any help will be appreciated.

I did some modifications to this pagination code to use a subfolder for each page, but it happens in the original code too.

Code: [Select]

<?php

class Paginate {

private
$perPage,
$maxShow,
$middle,
$href,
$current,
$lastPage;

public function __construct(
$href = '/',
$current = 0,
$total = 0,
$perPage = 10,
$maxShow = 10 //,
//$field = 'page'
) {

//$this->href = ' href="' . $href . (
// strpos($href, '?') === FALSE ? '?' : '&amp;'
//) . $field . '=';
$this->href = ' href="/blog/';
if (request::value()==='etiqueta') { 
$perPage = 5000;
$maxShow = 5000;
}
$this->current = $current;
$this->total = $total;
$this->perPage = $perPage;
$this->maxShow = $maxShow;
$this->middle = floor($maxShow / 2);
$this->lastPage = floor(($total - 1) / $perPage);

} // Paginate::__construct

public function getLimits() {
return [
':offset' => $this->current * $this->perPage,
':limit' => $this->perPage
];
}

private function anchorLine($page, $text, $title = false, $rel = false) {
$tag = $page < 0 ? 'span' : 'a';
if ($page===0 && request::value(1)!=='') 
echo '
<li><', $tag, (
$page >= 0 ? $this->href . '"' : ''
), (
$page == -2 ? ' class="disabled"' : ''
), (
$title ? ' title="' . $title . '"' : ''
), (
$rel ? ' rel="' . $rel . '"' : ''
), '>', $text, '</', $tag, '></li>';
else if ($page===0)
echo '
        <li><', $tag, (
          $page >= 0 ? $this->href . '/"' : ''
        ), (
          $page == -2 ? ' class="disabled"' : ''
        ), (
          $title ? ' title="' . $title . '"' : ''
        ), (
          $rel ? ' rel="' . $rel . '"' : ''
        ), '>', $text, '</', $tag, '></li>';
   else echo '
<li><', $tag, (
$page >= 0 ? $this->href . $page . '/"' : ''
), (
$page == -2 ? ' class="disabled"' : ''
), (
$title ? ' title="' . $title . '"' : ''
), (
$rel ? ' rel="' . $rel . '"' : ''
), '>', $text, '</', $tag, '></li>';
  }

public function show() {

  if ($this->total <= $this->perPage) return;

echo '<hr>
<ul class="pagination">';

if (($this->lastPage > 0) && ($this->current > 0)) {
$this->anchorLine(0, 'Primera');
$this->anchorLine($this->current - 1, '&#38;#38;#38;#x25C0;', 'Anterior', 'prev');
} else {
$this->anchorLine(-2, 'Primera');
$this->anchorLine(-2, '&#38;#38;#38;#x25C0;');
}

if ($this->lastPage >= $this->maxShow) {
$counter = ($this->current <= $this->middle) ? 0 : $this->current - $this->middle;
$endPage = $counter + $this->maxShow;
if ($endPage > $this->lastPage) {
$counter = $this->lastPage - $this->maxShow;
if ($counter < 0) $counter = 0;
$endPage = $this->lastPage;
}
} else {
$counter = 0;
$endPage = $this->lastPage;
}

while ($counter <= $endPage) $this->anchorLine(
$counter == $this->current ? -1 : $counter,
++$counter
);

if (($this->lastPage > 0) && ($this->current < $this->lastPage)) {
$this->anchorLine($this->current + 1, '&#38;#38;#38;#x25B6;', 'Siguiente', 'next');
$this->anchorLine($this->lastPage, 'Última');
} else {
$this->anchorLine(-2, '&#38;#38;#38;#x25B6;');
$this->anchorLine(-2, 'Última');
}
echo '
</ul>';

} // Paginate::show

} // Paginate


[Dave]

Doesn't work isn't really helpful I'm afraid. What errors do you get using the code?

[fgm]

Hello Dave, you are right, and that's part of my problem... I don't get any error, the output just stops when the code calls to the pagination functions.

I tried using error_reporting(E_ALL) without success. I suppose the code works fine but not the way I want.

[John_Betong]

@fgm,
> Hello Dave, you are right, and that's part of my problem... I don't get any error, the output just stops when the code calls to the pagination functions.


A couple of points to note:

1. error_reporting(E_ALL); // can be abbreviated to error_reporting(-1), see PHP Manual

2. Displaying errors depends on the php.ini -> display_errors  setting,  usually set to On locally and Off when online

3. Overriding the php.ini setting can be achieved by setting ini_set(‘display_errors’, ‘True’);

4. Errors still might not show if php.ini -> php_startup_errors = Off (default). This setting cannot be called using ini_set(‘display_startup_errors’, ‘True’); because the setting is ignored after the PHP page starts

5. When using PHP 8.?, at the start of the PHP file use declare(strict_types=1); which usually catches all errors and warnings. Unlike most php.ini settings the declaration is only valid for that file and does not affect any other include or require PHP files

[fgm]

That you a lot, John, that definitely helped. Now I get interesting information:

Code: [Select]

Fatal error: Uncaught TypeError: Unsupported operand types: string * int in /htd
ocs/example.com/libs/paginate.lib.php:41 Stack trace: #0 /htdocs/example.com/sta
tics/blog.php(46): Paginate->getLimits() #1 /htdocs/example.com/index.php(57): r
equire_once('/htdocs/example...') #2 {main} thrown in /htdocs/example.com/libs/p
aginate.lib.php on line 41

I'm going to look again in the PHP 7.4 to PHP 8.0 migration manual. I'd say this is the problematic line, but I don't know how to correct it:

Code: [Select]

':offset' => $this->current * $this->perPage,

-- update. Solved! thank you all a lot.

I changed this:

Code: [Select]

':offset' => (int)$this->current * (int)$this->perPage,

And this:

Code: [Select]

          $this->anchorLine($this->current - 1, '◀', 'Anterior', 'prev');

to this:

Code: [Select]

          $this->anchorLine((int)$this->current - 1, '◀', 'Anterior', 'prev');

I notice the forum inserts #38; in the code when modifying the post.

[John_Betong]

The error states that strings cannot be multiplied by a numeric:

Try typecasting the variables:

Code: [Select]

offset' => (int) $this->current * (int) $this->perPage,

Also to find the variable type and value:

Code: [Select]

echo ‘<pre>’; // add line feeds
  echo var_dump($this->current):
  echo var_dump($this->perPage);
echo ‘</pre>’;


[fgm]

It's fixed now, it just needed to cast some strings. Thank you!

[John_Betong]

Looks like I was a little late with my suggestions:)


If you have access to php.ini try searching for “<span…”and “</span”  and replace with “<pre…” and “</pre>”.


I have added CSS background colour yellow, linefeed and pre-overflow-auto, etc which makes the displayed errors far more readable. Only complication I have found is that php.ini is overwritten when updating

[fgm]

Thank you for the suggestions.

I have both PHP 7.4 and 8.1 installed, each of them with its own php.ini file: /etc/php-7.4.ini and /etc/php-8.1.ini