JR - php

paginator.php

<?php

function getPaginator($current_page, $total_pages, $boundaries, $around) {

  $paginator = array();
  $suspensionPoints = false;

  $paginator[$total_pages] = null;
  $paginator[$current_page] = null;

  for ( $i=1; $i<=$boundaries; $i++ ) {
      $paginator[$i] = null;
      $paginator[$total_pages - $i + 1] = null;
  }

  for ( $i=1; $i<=$around; $i++ ) {
    $paginator[$current_page - $i] = null;
    $paginator[$current_page + $i] = null;
  }

  foreach ($paginator as $key => $value) {
    if($key < 1 || $key > $total_pages) {
      unset($paginator[$key]);
    }
  }

  ksort($paginator);

  $paginator = array_keys($paginator);
  $paginator_clone = $paginator;
  $old_value = false;
  $shifts_needed = 0;

  //print_r($paginator);
  foreach($paginator_clone as $index => $val) {

    if ($old_value === false) {
        $old_value = $val;
        continue;
    }

    if (($val - $old_value) > 1) {
      //echo "gap found at: $index \n";
      $position = $index + $shifts_needed;
      $first_part = array_slice($paginator, 0, $position, true);
      $last_part = array_slice($paginator, $index, count($paginator) - 1, true);
      $paginator = array_merge($first_part, ['...'], $last_part);
      $shifts_needed += 1;
    }

    $old_value = $val;
  }


  echo implode(' ', $paginator) . "\n";
}

getPaginator(6,30,2,2); # [1,2,"...",4,5,6,7,8,29,30]
getPaginator(1,10,2,2); # [1,2,3,9,10]
getPaginator(10,10,10,0); # [1,2,3,4,5,6,7,8,9,10]
getPaginator(5,3,10,10);
getPaginator(4, 5, 1, 0); # [1, "...", 4, 5]
getPaginator(4, 10, 2, 2); # [1, 2, 3, 4, 5, 6, "...", 9, 10]
getPaginator(6, 30, 2, 2); #[1, 2, "...", 4, 5, 6, 7, 8, "...", 29, 30]
getPaginator(1, 10, 2, 2); # [1, 2, 3, "...", 9, 10]
getPaginator(6, 30, 2, 2); # [1, 2, 3, "...", 9, 10]
getPaginator(10, 10, 10, 10); # [1, "...", 4, 5]

/*
got:

1 2 ... 4 5 6 7 8 ... 8 29 30
1 2 3 ... 9 10
1 2 3 4 5 6 7 8 9 10
1 2 3
1 ... 4 5
1 2 3 4 5 6 ... 9 10
1 2 ... 4 5 6 7 8 ... 8 29 30
1 2 3 ... 9 10
1 2 ... 4 5 6 7 8 ... 8 29 30
1 2 3 4 5 6 7 8 9 10

*/