Pagination calculation routine #paginate #pagination

paginate.php

<?php

/* Wrote this for a pagination routine awhile back
   the variables needed
   $range = Amount of numbers to display
   $curpage = Current number
   $pages = Highest Page count
*/
        $midrange=intval(floor($range/2));
        $range_s=(($curpage-$midrange)<1?1:(($curpage+$midrange)>$pages?($pages-$range+1):$curpage-$midrange));
        $range_e=(($curpage+$midrange)>$pages?$pages:($curpage-$midrange<1?($range):$curpage+$midrange));

// I love the trenary operator keeps me from using a bunch of if...elseif..else statements

$midrange=intval(floor($range/2));         // find the middle of the range

// FInd the starting range
if(($curpage-$midrange)<1)    // If we subtract midrange from the current page, is it below page 1? 
  $range_s=1;    // Yes, well put the start at page 1 then
elseif(($curpage+$midrange)>$pages) // No, Well than If we add the midrange to the current page, are we above the highest page?
  $range_s=($pages-$range+1)    // Yes, well start at the lowest possible range than
else   $range_s=$curpage-$midrange; // No,  than go ahead subtract midrange from the current page

// find the ending range
if(($curpage+$midrange)>$pages)    // If we add the current page to our midrange, are we above the page count?
  $range_e=$pages;     // Yes, Well use the page count
elseif(($curpage-$midrange<1)    // No, Well than does the Lowest page invalid? 
  $range_e=$range;     // Yes, Well than use the Range instead of calculating
else   $range_e=$curpage+$midrange;   // No,  than go ahead add midrange to the current page

Even if this is quite old, it works pretty well, but I would add the following to the end to check that the result is between 1 and $pages. Currently it is possible that $range_s is contains negative values.

     $range_s = max($range_s, 1);
     $range_e = min($range_e, $pages);