wordpress Table of Contents

toc.php

/*-----------------------------------------------------------------------------------*/
/* Table of Contents - Shortcode */
/*-----------------------------------------------------------------------------------*/

if ( ! function_exists( 'woo_shortcode_table_of_contents' ) ) {
	function woo_shortcode_table_of_contents ( $atts, $content = null ) {
		global $post;
		$defaults = array();

		$atts = shortcode_atts( $defaults, $atts );

		extract( $atts );

		$table_of_contents = woo_get_table_of_contents( $post->post_content );

		$html = '';
		if ( isset( $table_of_contents['list'] ) && $table_of_contents['list'] != '<ol></ol>' ) {
			$html = '<div class="table_of_contents fl">' . '<h4>' . __( 'Contents', 'woothemes' ) . '</h4>' . $table_of_contents['list'] . '</div>' . "\n";
		}

		return apply_filters( 'woo_shortcode_table_of_contents', $html, $atts );
	} // End woo_shortcode_table_of_contents()
}

add_shortcode( 'table_of_contents', 'woo_shortcode_table_of_contents' );

/*-----------------------------------------------------------------------------------*/
/* Table of Contents - Content Filter */
/*-----------------------------------------------------------------------------------*/

add_filter( 'the_content', 'woo_table_of_contents_section_anchors', 10 );

if ( ! function_exists( 'woo_table_of_contents_section_anchors' ) ) {
	function woo_table_of_contents_section_anchors ( $content ) {
		$data = woo_get_table_of_contents( $content );

		foreach ( $data['sections_with_ids'] as $k => $v ) {
	  		$content = str_replace( $data['sections'][$k], $v, $content );
	 	}

		return $content;
	} // End woo_table_of_contents_section_anchors()
}

/*-----------------------------------------------------------------------------------*/
/* Table of Contents - Automation */
/*-----------------------------------------------------------------------------------*/

if ( isset( $woo_options['woo_auto_tableofcontents'] ) && ( apply_filters( 'woo_auto_tableofcontents', $woo_options['woo_auto_tableofcontents'] ) != 'false' ) ) {
	add_filter( 'the_content', 'woo_table_of_contents_automation', 10 );
}

if ( ! function_exists( 'woo_table_of_contents_automation' ) ) {
	function woo_table_of_contents_automation ( $content ) {
		if ( is_singular() && in_the_loop() ) {
			$content = '[table_of_contents] ' . $content;
		}

		return $content;
	} // End woo_table_of_contents_automation()
}

/*-----------------------------------------------------------------------------------*/
/* Table of Contents - Generator */
/*-----------------------------------------------------------------------------------*/

if ( ! function_exists( 'woo_get_table_of_contents' ) ) {
	function woo_get_table_of_contents ( $content ) {
	  preg_match_all( "/(<h([0-6]{1})[^<>]*>)([^<>]+)(<\/h[0-6]{1}>)/", $content, $matches, PREG_SET_ORDER );
	  $count = 0; // List Item Count
	  $level = 1; // Heading Level
	  $list = array();
	  $sections = array();
	  $sections_with_ids = array();

	  foreach ( $matches as $val ) {
		$count++;

		if ( $val[2] == $level ) { // If the heading level didn’t change.
			$list[$count] = '<li><a href="#section-' . $count . '">'. $val[3] . '</a>';

		} else if ( $val[2] > $level ) { // If bigger then last heading level, create a nested list.
			$difference = ( intval( $val[2] - $level ) );

			$openers = '';

			if ( $difference < 1 ) $difference = 1;
			for ($i = 0; $i < $difference; $i++) {
				$openers .= '<ol>';
			}


			$list[$count] = $openers . '<li><a href="#section-' . $count . '">'. $val[3] . '</a>';

		} else if ( $val[2] < $level ) { // If less then last Heading Level, end nested list.
			// Account for the number of subheadings, to make sure we indent at the correct level.
			$difference = ( $level - intval( $val[2] ) );
			if ( $difference < 1 ) $difference = 1;

			$closers = '';

			if ( $difference > 1 ) { $closers .= '</ol>'; }

			if ( 0 < $difference ) {
				for ( $i = 0; $i < $difference; $i++ ) {
					if ( $i > 0 || $difference == 1 ) { $closers .= '</ol>'; }
					$closers .= '</li>';

				}
			}

			$list[$count] = $closers . '<li><a href="#section-' . $count . '">'. $val[3] . '</a>';
		}

		$sections[$count] = $val[1] . $val[3] . $val[4]; // Original heading to be Replaced.
		$sections_with_ids[$count] = '<h' . $val[2] . ' id="section-' . $count . '">' . $val[3] . $val[4]; // This is the new Heading.

		$level = $val[2];
	  }

	  switch ( $level ) { // Final markup fix, used if the list ended on a subheading, such as h3, h4. Etc.
	    case 2:
	     $list[$count] .= '</li>';
	    break;
	    case 3:
	     $list[$count] .= '</ol></li>';
	    break;
	    case 4:
	     $list[$count] .= '</ol></li></ol></li>';
	    break;
	    case 5:
	     $list[$count] .= '</ol></li></ol></li></ol></li>';
	    break;
	    case 6:
	     $list[$count] .= '</ol></li></ol></li></ol></li></ol></li></ol></li>';
	    break;
	  }

	  // Setup container to store rendered HTML.
	  $html = '';

	  foreach ( $list as $k => $v ) { // Puts together the list.
	    $html .= $v;
	  }

	  $html = stripslashes( $html );

	  // Add opening and closing <ol> tags only when necessary.
	  if ( substr( $html, 0, 4 ) != '<ol>' ) {
	  	$html = '<ol>' . $html;
	  }

	  if ( substr( $html, -5 ) != '</ol>' ) {
	  	$html .= '</ol>';
	  }

	  return array( 'list' => $html, 'sections' => $sections, 'sections_with_ids' => $sections_with_ids ); // Returns the content
	} // End woo_get_table_of_contents()
}