class-social-walker.php

<?php

/**
 * description of package
 *
 * @package    YourPackage
 * @subpackage Subpackage name
 * @author     firstname lastname <user@host.com>
 */
class Social_Walker extends Walker_Nav_Menu {

	/**
	 * Tell Walker where to inherit it's parent and id values.
	 *
	 * @var array $db_fields fields for query.
	 */
	public $db_fields = array(
		'parent' => 'menu_item_parent',
		'id'     => 'db_id',
	);


	/**
	 * Start the element output.
	 *
	 * @see Walker::start_el()
	 *
	 * @since 3.0.0
	 *
	 * @param string $output Passed by reference. Used to append additional content.
	 * @param object $item   Menu item data object.
	 * @param int    $depth  Depth of menu item. Used for padding.
	 * @param array  $args   An array of arguments. @see wp_nav_menu()
	 * @param int    $id     Current item ID.
	 */
	public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
		$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

		$li_classes  = array();
		$a_classes   = array();
		$img_classes = array( 'screen-reader-text' );

		$classes   = empty( $item->classes ) ? array() : (array) $item->classes;
		$classes[] = 'social-menu-item-' . $item->ID;
		foreach ( $classes as $class_name ) {
			$li_classes[] = $class_name;
		}

		/**
		 * Filter the CSS class(es) applied to a menu item's <li>.
		 *
		 * @since 3.0.0
		 *
		 * @see wp_nav_menu()
		 *
		 * @param array  $classes The CSS classes that are applied to the menu item's <li>.
		 * @param object $item    The current menu item.
		 * @param array  $args    An array of wp_nav_menu() arguments.
		 */
		$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $li_classes ), $item, $args ) );
		$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

		/**
		 * Filter the ID applied to a menu item's <li>.
		 *
		 * @since 3.0.1
		 *
		 * @see wp_nav_menu()
		 *
		 * @param string $menu_id The ID that is applied to the menu item's <li>.
		 * @param object $item    The current menu item.
		 * @param array  $args    An array of wp_nav_menu() arguments.
		 */
		$id = apply_filters( 'nav_menu_item_id', 'menu-item-' . $item->ID, $item, $args );
		$id = $id ? ' id="' . esc_attr( $id ) . '"' : '';

		$output .= $indent . '<li' . $id . $class_names . '>';

		$atts           = array();
		$atts['class']  = implode( ' ', $a_classes );
		$atts['title']  = ! empty( $item->attr_title ) ? $item->attr_title : '';
		$atts['target'] = ! empty( $item->target ) ? $item->target : '';
		$atts['rel']    = ! empty( $item->xfn ) ? $item->xfn : '';
		$atts['href']   = ! empty( $item->url ) ? $item->url : '';

		/**
		 * Filter the HTML attributes applied to a menu item's <a>.
		 *
		 * @since 3.6.0
		 *
		 * @see wp_nav_menu()
		 *
		 * @param array $atts {
		 *     The HTML attributes applied to the menu item's <a>, empty strings are ignored.
		 *
		 *     @type  string $title  Title attribute.
		 *     @type  string $target Target attribute.
		 *     @type  string $rel    The rel attribute.
		 *     @type  string $href   The href attribute.
		 * }
		 * @param object $item The current menu item.
		 * @param array  $args An array of wp_nav_menu() arguments.
		 */
		$atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );

		$attributes = '';
		foreach ( $atts as $attr => $value ) {
			if ( ! empty( $value ) ) {
				$value       = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
				$attributes .= ' ' . $attr . '="' . $value . '"';
			}
		}
		$args                = (object) $args;
		list( $name, $size ) = explode( '-', $classes[0] );
		$size                = isset( $size ) ? $size : 44;
		$img_url             = $this->class_to_icon_url( $name, $size );

		$item_title = apply_filters( 'the_title', $item->title, $item->ID );

		$item_output  = $args->before;
		$item_output .= '<a' . $attributes . '>';
		/**
		 * This filter is documented in wp-includes/post-template.php
		 */
		$item_output .= $args->link_before;
		$item_output .= sprintf(
			'<img src="%s" height="%d" width="%d" alt="%s">',
			$img_url,
			$size,
			$size,
			$item_title
		);
		$item_output .= $args->link_after;
		$item_output .= '</a>';
		$item_output .= $args->after;

		/**
		 * Filter a menu item's starting output.
		 *
		 * The menu item's starting output only includes $args->before, the opening <a>,
		 * the menu item's title, the closing </a>, and $args->after. Currently, there is
		 * no filter for modifying the opening and closing <li> for a menu item.
		 *
		 * @since 3.0.0
		 *
		 * @see wp_nav_menu()
		 *
		 * @param string $item_output The menu item's starting HTML output.
		 * @param object $item        Menu item data object.
		 * @param int    $depth       Depth of menu item. Used for padding.
		 * @param array  $args        An array of wp_nav_menu() arguments.
		 */
		$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
	}

	/**
	 * Create an image url based on a class name.
	 *
	 * @param string   $name the name of the class.
	 * @param int|bool $size the dimensions of the image.
	 *
	 * @return string
	 */
	protected function class_to_icon_url( $name, $size = false ) {

		$filename = "icons8-{$name}.png";

		$img_url  = get_template_directory_uri();
		$img_url .= '/img/social-icons';
		$img_url .= '/' . $filename;

		return $img_url;
	}
}