<?php
/**
tablepager - php pager for splitting up database rows/items on to multiple pages
Version 0.1.1
Copyright (C) 2003 Greg MacLellan
Aug 22/2003

greg at mtechsolutions dot ca

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    http://www.gnu.org/licenses/lgpl.html


There's still a couple things this doesnt do (inconsistent with the examples, btw!)

If surrounding = 2, and the currentpage is 4, it will show:
"... 2 3 4 5 6 ..."

There's really no point in blocking "1" with "...", so that should override that behaviour

Same thing happens when firstlast = true, if surrounding = 2 and currentpage = 5,
"1 ... 3 4 5 6 7 ... 12"

There's no point in blocking the "2". I started to add an override for this (in the 
"if ($cond_notblocked == false)" section on line 131), but never finished it. If anyone cares,
feel free.


I also don't know if appending to a string is really the best way to build the output,
it might be more efficient with an array and then using implode() later? Just a thought,
this was just hacked together fairly quickly, but I hope it will be useful to others, 
which is why I released it under LGPL.

If you make any fixes, or have comments, email me. Address is above

-greg

*/
class tablepager {
	var $_totalRows;
	var $_rowsPerPage;
	var $_currentPage;

	/** Create a new tablepager, for splitting up rows from a database or other list into
	 * seperate pages
	 * @param int	$totalRows	Total number of rows in the full result set
	 * @param int	$rowsPerPage	How many rows to display per page
	 * @param int	$currentPage	The current page number (starting at 1)
	 */
	function tablepager($totalRows, $rowsPerPage, $currentPage = 1) {
		$this->_totalRows = $totalRows;
		$this->_rowsPerPage = $rowsPerPage;
		$this->_currentPage = $currentPage;
	}

	/** The number of pages
	 */
	function getNumPages() {
		return ceil($this->_totalRows / $this->_rowsPerPage);
	}

	/** The current offset into the results
	 */
	function getOffset() {
		return $this->_currentPage * $this->_rowsPerPage;
	}

	/** Returns a limit clause for SQL statments, based on current page
	*/
	function getLimitClause() {
		return "LIMIT ".$this->_rowsPerPage.",".$this->getOffset();
	}
	
	/** Show a page selector
	 * Example matrix: (12 pages total, 8 is current page
	 *  Output                            $surrounding $nextprev $firstlast
	 *  --------------------------------- ------------ --------- ----------
	 *  < 1 .. 7 8 9 .. 12 >              1            true      true
	 *  < .. 7 8 9 .. >                   1            true      false
	 *  1 .. 7 8 9 .. 12                  1            false     true
	 *  < 1 .. 5 6 7 8 9 10 11 12 >       3            true      true
	 *  < 1 .. 6 7 8 9 10 11 12 >         2            true      true
	 *  < 1 2 3 4 5 6 7 8 9 10 11 12 >    false        true      true
	 *
	 *
	 * @param string	$urlprefix	Should be of the form "file.php?page=". The page
	 *					number will be concatenated on to the end
	 * @param int		$surrounding	Controls blanking out of page numbers. If False,
	 *					all page numbers are shown. If any integer, then
	 *					that number of page numbers are shown next to
	 *					the current page, and the rest are seperated with "..."
	 * @param bool		$nextprev	True to show < and > arrows at the ends of the string,
	 *					to link to previous/next page
	 * @param bool		$firstlast	True to always show a number for the first and last
	 *					pages, regardless of $surrounding setting. This has
	 *					no effect if $surrounding = false, since all pages
	 *					are shown anyways.
	*/
	function showPager($urlprefix, $surrounding = false, $nextprev = true, $firstlast = true) {
		$out = "";
		if ($nextprev && ($this->_currentPage > 1)) {
			// show previous button, if applicable
			$out .= "<a href=\"".$urlprefix.($this->_currentPage - 1)."\">&lt;</a>&nbsp;";
		}

		$total = $this->getNumPages();

		for ($i = 1; $i <= $total; $i++) {
			$cond_showall = false;
			$cond_notblocked = false;
			$cond_firstlast = false;
			//echo " [$i]";

			// not blocking any numbers, so show them all
			$cond_showall = ($surrounding === false);
			//echo ($cond_showall ? "<b>1</b>" : "1");

			if (!$cond_showall) {
				// if we are blocking, is this within +/- $surrounding numbers from current page?
				$cond_notblocked = (abs($this->_currentPage - $i) <= $surrounding);
				//echo ($cond_notblocked ? "<b>2</b>" : "2");

				if ($cond_notblocked == false) {
					// its blocked, lets check if it should be unblocked
					if ($firstlast) {
						//$cond_notblocked = ($i <= 2);
					} else {
					}
				}

				// if using $firstlast, then if this is the first or last, show it
				$cond_firstlast = ($firstlast && (($i == 1) || ($i == $total)));
				//echo ($cond_firstlast ? "<b>3</b>" : "3");
			}

			if ($cond_showall || $cond_notblocked || $cond_firstlast) {
				if ($this->_currentPage == $i) {
					$out .= $i."&nbsp";
				} else {
					$out .= "<a href=\"".$urlprefix.$i."\">".$i."</a>&nbsp;";
				}
			} else {
				$out .= ".";
			}
		}

		if ($nextprev && ($this->_currentPage < $total)) {
			// show next button, if applicable
			$out .= "<a href=\"".$urlprefix.($this->_currentPage + 1)."\">&gt;</a>&nbsp;";
		}
		
		// replace all our non-numbers with just "..."
		// probably not the most efficient way, but works well
		$out = preg_replace("/\.+/","... ",$out);

		return $out;
	}
}

echo "<p>showPager(surrounding = 2, nextprev = true, firstlast = true)<br>";
for ($i = 1; $i < 13; $i++) {
	$pager = new tablepager(115, 10, $i);
	echo $pager->showPager("?page=", 2, true, true)."<br>";
}

echo "<p>showPager(surrounding = 2, nextprev = true, firstlast = false)<br>";
for ($i = 1; $i < 13; $i++) {
	$pager = new tablepager(115, 10, $i);
	echo $pager->showPager("?page=", 2, true, false)."<br>";
}

echo "<p>showPager(surrounding = false, nextprev = true, firstlast = true)<br>";
for ($i = 1; $i < 13; $i++) {
	$pager = new tablepager(115, 10, $i);
	echo $pager->showPager("?page=", false, true, true)."<br>";
}

?>