+ // the user's options are the third parameter
+ if ( empty($args[2]['walker']) || !is_a($args[2]['walker'], 'Walker') )
+ $walker = new Walker_CategoryDropdown;
+ else
+ $walker = $args[2]['walker'];
+
+ return call_user_func_array(array( &$walker, 'walk' ), $args );
+}
+
+/**
+ * Create HTML list of categories.
+ *
+ * @package WordPress
+ * @since 2.1.0
+ * @uses Walker
+ */
+class Walker_Category extends Walker {
+ /**
+ * What the class handles.
+ *
+ * @see Walker::$tree_type
+ * @since 2.1.0
+ * @var string
+ */
+ public $tree_type = 'category';
+
+ /**
+ * Database fields to use.
+ *
+ * @see Walker::$db_fields
+ * @since 2.1.0
+ * @todo Decouple this
+ * @var array
+ */
+ public $db_fields = array ('parent' => 'parent', 'id' => 'term_id');
+
+ /**
+ * Starts the list before the elements are added.
+ *
+ * @see Walker::start_lvl()
+ *
+ * @since 2.1.0
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param int $depth Depth of category. Used for tab indentation.
+ * @param array $args An array of arguments. Will only append content if style argument value is 'list'.
+ * @see wp_list_categories()
+ */
+ public function start_lvl( &$output, $depth = 0, $args = array() ) {
+ if ( 'list' != $args['style'] )
+ return;
+
+ $indent = str_repeat("\t", $depth);
+ $output .= "$indent<ul class='children'>\n";
+ }
+
+ /**
+ * Ends the list of after the elements are added.
+ *
+ * @see Walker::end_lvl()
+ *
+ * @since 2.1.0
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param int $depth Depth of category. Used for tab indentation.
+ * @param array $args An array of arguments. Will only append content if style argument value is 'list'.
+ * @wsee wp_list_categories()
+ */
+ public function end_lvl( &$output, $depth = 0, $args = array() ) {
+ if ( 'list' != $args['style'] )
+ return;
+
+ $indent = str_repeat("\t", $depth);
+ $output .= "$indent</ul>\n";
+ }
+
+ /**
+ * Start the element output.
+ *
+ * @see Walker::start_el()
+ *
+ * @since 2.1.0
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param object $category Category data object.
+ * @param int $depth Depth of category in reference to parents. Default 0.
+ * @param array $args An array of arguments. @see wp_list_categories()
+ * @param int $id ID of the current category.
+ */
+ public function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
+ /** This filter is documented in wp-includes/category-template.php */
+ $cat_name = apply_filters(
+ 'list_cats',
+ esc_attr( $category->name ),
+ $category
+ );
+
+ $link = '<a href="' . esc_url( get_term_link( $category ) ) . '" ';
+ if ( $args['use_desc_for_title'] && ! empty( $category->description ) ) {
+ /**
+ * Filter the category description for display.
+ *
+ * @since 1.2.0
+ *
+ * @param string $description Category description.
+ * @param object $category Category object.
+ */
+ $link .= 'title="' . esc_attr( strip_tags( apply_filters( 'category_description', $category->description, $category ) ) ) . '"';
+ }
+
+ $link .= '>';
+ $link .= $cat_name . '</a>';
+
+ if ( ! empty( $args['feed_image'] ) || ! empty( $args['feed'] ) ) {
+ $link .= ' ';
+
+ if ( empty( $args['feed_image'] ) ) {
+ $link .= '(';
+ }
+
+ $link .= '<a href="' . esc_url( get_term_feed_link( $category->term_id, $category->taxonomy, $args['feed_type'] ) ) . '"';
+
+ if ( empty( $args['feed'] ) ) {
+ $alt = ' alt="' . sprintf(__( 'Feed for all posts filed under %s' ), $cat_name ) . '"';
+ } else {
+ $alt = ' alt="' . $args['feed'] . '"';
+ $name = $args['feed'];
+ $link .= empty( $args['title'] ) ? '' : $args['title'];
+ }
+
+ $link .= '>';
+
+ if ( empty( $args['feed_image'] ) ) {
+ $link .= $name;
+ } else {
+ $link .= "<img src='" . $args['feed_image'] . "'$alt" . ' />';
+ }
+ $link .= '</a>';
+
+ if ( empty( $args['feed_image'] ) ) {
+ $link .= ')';
+ }
+ }
+
+ if ( ! empty( $args['show_count'] ) ) {
+ $link .= ' (' . number_format_i18n( $category->count ) . ')';
+ }
+ if ( 'list' == $args['style'] ) {
+ $output .= "\t<li";
+ $class = 'cat-item cat-item-' . $category->term_id;
+ if ( ! empty( $args['current_category'] ) ) {
+ $_current_category = get_term( $args['current_category'], $category->taxonomy );
+ if ( $category->term_id == $args['current_category'] ) {
+ $class .= ' current-cat';
+ } elseif ( $category->term_id == $_current_category->parent ) {
+ $class .= ' current-cat-parent';
+ }
+ }
+ $output .= ' class="' . $class . '"';
+ $output .= ">$link\n";
+ } else {
+ $output .= "\t$link<br />\n";
+ }
+ }
+
+ /**
+ * Ends the element output, if needed.
+ *
+ * @see Walker::end_el()
+ *
+ * @since 2.1.0
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param object $page Not used.
+ * @param int $depth Depth of category. Not used.
+ * @param array $args An array of arguments. Only uses 'list' for whether should append to output. @see wp_list_categories()
+ */
+ public function end_el( &$output, $page, $depth = 0, $args = array() ) {
+ if ( 'list' != $args['style'] )
+ return;
+
+ $output .= "</li>\n";
+ }
+
+}
+
+/**
+ * Create HTML dropdown list of Categories.
+ *
+ * @package WordPress
+ * @since 2.1.0
+ * @uses Walker
+ */
+class Walker_CategoryDropdown extends Walker {
+ /**
+ * @see Walker::$tree_type
+ * @since 2.1.0
+ * @var string
+ */
+ public $tree_type = 'category';
+
+ /**
+ * @see Walker::$db_fields
+ * @since 2.1.0
+ * @todo Decouple this
+ * @var array
+ */
+ public $db_fields = array ('parent' => 'parent', 'id' => 'term_id');
+
+ /**
+ * Start the element output.
+ *
+ * @see Walker::start_el()
+ * @since 2.1.0
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param object $category Category data object.
+ * @param int $depth Depth of category. Used for padding.
+ * @param array $args Uses 'selected' and 'show_count' keys, if they exist. @see wp_dropdown_categories()
+ */
+ public function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
+ $pad = str_repeat(' ', $depth * 3);
+
+ /** This filter is documented in wp-includes/category-template.php */
+ $cat_name = apply_filters( 'list_cats', $category->name, $category );
+
+ $output .= "\t<option class=\"level-$depth\" value=\"".$category->term_id."\"";
+ if ( $category->term_id == $args['selected'] )
+ $output .= ' selected="selected"';
+ $output .= '>';
+ $output .= $pad.$cat_name;
+ if ( $args['show_count'] )
+ $output .= ' ('. number_format_i18n( $category->count ) .')';
+ $output .= "</option>\n";
+ }