Genbu Table Of Content Shortcode

gtoc.php

<?php
/*
 * Genbu Table Of Content Shortcode
 * use [gtoc] to generate shortcode
 *
 * This program 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.
 *
 * Based on (credit) :
 * WP TOC by Brendon Boshell http://infinity-infinity.com/
 *
 * @package Genbu TOC
 * @since 1.0.0
*/
add_action('after_setup_theme','genbu_toc_setup');
function genbu_toc_setup(){
	/* Genbu Table of Content. */
	add_shortcode( "gtoc", "genbu_toc_shortcode_toc" );
	add_action( "the_content", "genbu_toc_the_content" );
	//remove_filter('the_content', 'wptexturize');

}

// open a nested list
function genbu_toc_open_level($new, $cur, $first, $type) {
	$levels = $new - $cur;
	$out = "";
	for($i = $cur; $i < $new; $i++) {
	
		$level = $i - $first + 2;
		if(($level % 2) == 0)
			$out .= "<{$type} class='toc-even level-{$level}'>\n";
		else
			$out .= "<{$type} class='toc-odd level-{$level}'>\n";
	}
	return $out;
}

// close the list
function genbu_toc_close_level( $new, $cur, $first, $type ) {
	$out = "";
	for($i = $cur; $i > $new; $i--)
		$out .= "</{$type}>\n";
	return $out;
}

$wptoc_used_names = array();

function genbu_toc_get_unique_name($heading) {
	global $wptoc_used_names;
	
	$n = strip_tags($heading);
	$n = str_replace('"', '', strip_tags($heading));
	$n = str_replace(" ", "_", $heading);
	$n = preg_replace("#[^A-Za-z0-9\-_\:\.]#", "", $n);
	$n = preg_replace("#^[^A-Za-z]*?([A-Za-z])#", "$1", $n);
	
	
	if (isset($wptoc_used_names[$n])) {
		$wptoc_used_names[$n]++;
		$n .= "_" . $wptoc_used_names[$n];	
		$wptoc_used_names[$n] = 0;	
	} else {
		$wptoc_used_names[$n] = 0;
	}
	
	return $n;
}

function genbu_toc_unique_names_reset() {
	global $wptoc_used_names;
	$wptoc_used_names = array();
	return true;
}

function genbu_toc_shortcode_toc($attribs) {
	global $post;
	if (is_singular() && !is_attachment()){
	genbu_toc_unique_names_reset();
	
	// REMOVE PLUGIN OPTION
	$attribs = shortcode_atts(
		array(
			"depth" => 20,
			"listtype" => 'ul',
			"title" => __('Table Of Content:','tamatebako')
		), 
		$attribs);
		
	extract($attribs);
	
	$depth = $depth ? $depth : 20;	
	$list_type = $listtype ? $listtype : "ul";
	$title = $title ? $title : __('Table Of Content:','tamatebako');

	// get the post
	// don't consider stuff in <pre>s
	$content = preg_replace("#<pre.*?>(.|\n|\r)*?<\/pre>#i", "", $post->post_content);
	
	$lowest_heading = 1;
	
	// calculate the lowest value heading (ie <hN> where N is a number)
	// in the post
	for($i = 1; $i <= 6; $i++)
		if( preg_match("#<h" . $i . "#i", $content) ) {
			$lowest_heading = $i;
			break;
		}
		
	// maximum
	$max_heading = $lowest_heading + $depth - 1;
	
	// find page separation points
	$next_pages = array();
	preg_match_all("#<\!--nextpage-->#i", $content, $next_pages, PREG_OFFSET_CAPTURE);
	$next_pages = $next_pages[0];
	
	// get all headings in post
	$headings = array();
	preg_match_all("#<h([1-6])>(.*?)</h[1-6]>#i", $content, $headings, PREG_OFFSET_CAPTURE);
	
	$cur_level = $lowest_heading;
	
	$out = '<div id="table-of-content">';
	
	if ($title) 
		$out .= '<div id="toc-title">' . $title . '</div>';
		
	$out .= genbu_toc_open_level($lowest_heading, $lowest_heading-1, $lowest_heading, $list_type);	
	
	$first = true;
	
	$tabs = 1;
	
	// headings...
	foreach($headings[2] as $i => $heading) {
		$level = $headings[1][$i][0]; // <hN>
		
		if($level > $max_heading) // heading too deep
			continue;
		
		if($level > $cur_level) { // this needs to be nested
			$out .= str_repeat("\t", $tabs+1) . genbu_toc_open_level( $level, $cur_level, $lowest_heading, $list_type );
			$first = true;
			$tabs += 2;
		}
			
		if(!$first)
			$out .= str_repeat("\t", $tabs) . "</li>\n";
		$first = false;
			
		if($level < $cur_level) { // jump back up from nest
			$out .= str_repeat("\t", $tabs-1) . genbu_toc_close_level( $level, $cur_level, $lowest_heading, $list_type );
			$tabs -= 2;
		}
			
		$name = genbu_toc_get_unique_name($heading[0]);

		$page_num = 1;
		$pos = $heading[1];
		
		// find the current page
		foreach($next_pages as $p) {
			if($p[1] < $pos)
				$page_num++;
		}
		// fix error if heading link overlap / not hieraricaly correct
		if ($tabs+1 > 0) {
			$tabs = $tabs;
		}
		else {
			$tabs = 0;
		}
		// output the Contents item with link to the heading. Uses
		// unique ID based on the $prefix variable.
		if($page_num != 1)
			$out .= str_repeat("\t", $tabs) . "<li>\n" . str_repeat("\t", $tabs+1) . "<a href=\"?p=" . $post->ID . "&page=" . $page_num . "#" . esc_attr($name). "\">" . $heading[0] . "</a>\n";
		else
			$out .= str_repeat("\t", $tabs) . "<li>\n" . str_repeat("\t", $tabs+1) . "<a href=\"#" . esc_attr($name). "\">" . $heading[0] . "</a>\n";
			
		$cur_level = $level; // set the current level we are at
	}
	
	if(!$first)
		$out .= str_repeat("\t", $tabs) . "</li>\n";
	
	// close up the list
	$out .= genbu_toc_close_level( 0, $cur_level, $lowest_heading, $list_type );
	
	$out .= "</div>\n";
	
	// return value to repalce the Shortcode
	return $out;
	}
}

function genbu_toc_heading_anchor($match) {
	
	$name = genbu_toc_get_unique_name($match[2]);

	return '<span id="' .esc_attr($name) . '">' . $match[0] . '</span>';
}

function genbu_toc_the_content($content) {
	
	genbu_toc_unique_names_reset();
	
	$out = preg_replace_callback("#<h([1-6])>(.*?)</h[1-6]>#i", "genbu_toc_heading_anchor", $content);
	return $out;
}