custom_search.php

<div id="content" class="col-full">
    	
	<section id="main" class="col-left">
		
	<!-- begin search form -->
    	<form action="/library" method="post">
    			
		<p>
			<label for="query"><?php _e( 'Search', 'woothemes' ); ?></label>
			<input type="text" name="query" id="query" value="<?php echo esc_attr( $query ); ?>" />
		</p>
		<p>
			<input type="submit" id="searchsubmit" value="<?php _e( 'Search', 'woothemes' ); ?>" />
		</p>

    	</form>
    	<!-- end search form -->   	
    	
    	<?php 
    	
    	if( !empty( $query ) ) : 

        	$product_cats = 'books, renew, sanctuary';
  
  		$args = array(
  			'posts_per_page' => -1,
  			'post_type' => 'product',
			'orderby' => 'date menu_order', 
			'order' => 'DESC',
			's' => $query,
			'sentence' => 1,
			'product_cat' => $product_cats,
			
		);
  
         	// perform the search
        	$posts = new WP_Query( $args );

      		if( ( $posts->have_posts() ) ) : 
      		
      		?>

        		<header class="page-header">
          			<h1 class="page-title"><?php printf( __( 'Library Search Results for: %s', 'woothemes' ), $query ); ?></h1>
        		</header>

        		<?php /* The loop */ ?>
        		
        			<ul style="list-style: none">
        		
        		<?php  
        		      
        		while ( $posts->have_posts() ): $posts->the_post(); 
        		?>
          			<li style="display: block; margin-bottom: 50px">
							
					<div style="float: left; width: 110px;">	
					
						<a href="<?php echo get_permalink(); ?>">
							<?php echo get_the_post_thumbnail( $post->ID, array( 175, 175 ) ); ?>
						</a>
							
					</div>

					<div style="float:left; margin-left: 20px; width: 500px">
							
						<h2 style="margin-top: -10px; padding-top: 0px;">		
							<a href="<?php echo get_permalink(); ?>"	
								<?php echo apply_highlight( get_the_title() , $query ) ?>
							</a>
						</h2>
							
						<div><?php echo apply_highlight( get_snippet( get_the_content() , $query ) , $query ) ?></div>
								
					</div>
							
					<div style="clear:both"></div>
          				
          			</li>
          		<?php
        		endwhile; 
        		
        		?>
        			</ul>
        		<?php

        		wp_reset_postdata();
        		
        		?>


      		<?php 
      		
      		else : 
      		
      		?>
				
				<h1 class="page-title"><?php printf( __( 'Sorry, no matches found for "' . $query .'"', 'woothemes' )  ); ?></h1>
 
				<h4>Search Suggestions:</h4>
				<ul>
					<li>Check your spelling</li>
					<li>Try more general words</li>
					<li>Try different words that mean the same thing</li>
				</ul>
					
				<h1 class="page-title">Or, perhaps these might be of interest...</h1>
					
				<?php
								
						echo do_shortcode('[product_category per_page="3" columns="3" orderby="date" order="desc" category="books"]'); 
													
						echo do_shortcode('[product_category per_page="3" columns="3" orderby="date" order="desc" category="renew"]'); 

						echo do_shortcode('[product_category per_page="3" columns="3" orderby="date" order="desc" category="sanctuary"]'); 				
				
			endif; // !(empty ( $posts ))

		endif; // !(empty ( $query ))
		
		?>
                
        </section><!-- /#main -->

</div><!-- /#content -->

helper_functions.php

function apply_highlight( $the_content , $the_query) {

	return preg_replace( '/' . $the_query . '/i' , '<span style="background-color: #00FF00">$0</span>' , $the_content );

}

function get_snippet( $the_content , $the_query ) {

	preg_match( '/' . $the_query . '/i' , $the_content , $matches, PREG_OFFSET_CAPTURE );
	
	$snippet = '<ul>';
	
	foreach ($matches as $match):

		$cutoff = substr( $the_content, 0 , $match[1] );
		
		$start = strripos( $cutoff, '<li>' );
		$end = strpos( $the_content, '</li>' , $match[1] );
		
		$snippet .= substr( $the_content, $start, ( $end - $start ) + 4 );
		
		//$snippet .= $match[0] . ' - ' . $match[1];

	endforeach;

	$snippet .= '</ul>';
	
	return $snippet;
}