create_post_series_box

part of GWP tutorial : https://generatewp.com/group-post-series-custom-taxonomy

	/*
	 * create_post_series_box
	 * Create post series box html markup
	 * @param  int 		$current_id      	current post ID.
	 * @param  array 	$posts_in_series 	array of post IDs.
	 * @param  WP_Term 	$series          	Post Series taxonomy term.
	 * @return string 						HTML markup of post series box
	 */
	function create_post_series_box( $current_id, $posts_in_series, $series ){
		//box template (filterable)
		$template = apply_filters( 'GWP_series_box_template', '
			<div id="post-series">
				<div class="series-title">Post Series: {series_title}</div>
				{series_list}
			</div>
		');

		//list tag (filterable) 
		$list_tag = apply_filters( 'GWP_series_list_tag', 'ul' );
		
		//create an array of all posts in series as li tags
		$items = array();
		foreach ( $posts_in_series as $id ) {
			$title = get_the_title( $id );
			if ( $id == $current_id ){
				//this is the current post so no link anchor tag is needed
				$items[] = '<li class="current series-item">' . $title .'</li>';	
			}else{
				$items[] = '<li class="series-item"><a title="'.esc_attr( $title ).'" href="' .get_permalink( $id ) .'">' . $title .'</a></li>';
			}
		}
		//connect the items to a list
		$list = '<' . $list_tag .'>' . implode( "n", $items ). '</'. $list_tag .'>'; 

		//array of template tokens
		$search = array(
			'{series_id}',
			'{series_slug}',
			'{series_title}',
			'{series_description}',
			'{series_url}',
			'{series_list}'
		);

		//array of token replacements
		$replace = array(
			$series->term_id,
			$series->slug,
			$series->name,
			$series->description,
			get_term_link( $series, $this->tax_name ),
			$list
		);

		//replace tokens in template with actual data
		$box = str_replace( $search, $replace, $template );

		//return box html (filterable)
		return apply_filters( 'GWP_series_box', $box, $current_id, $posts_in_series, $series );
	}