The code below is an attempt to take the WP_Widget_Categories class and use it as the basis for a custom categories widget based on the default categories widget.
I’m getting no output however and the widget is not showing up in the “Available Widgets” listing. What am I doing wrong?
<?php
/*
Plugin Name: My Categories Widget
Version: 1.0
*/
class MY_Widget_Categories extends WP_Widget {
function MY_Widget_Categories() {
$widget_ops = array( 'classname' => 'widget_categories', 'description' => __( "A list or dropdown of categories" ) );
$this->WP_Widget('categories', __('Categories'), $widget_ops);
}
function widget( $args, $instance ) {
extract( $args );
$title = apply_filters('widget_title', empty( $instance['title'] ) ? __( 'Categories' ) : $instance['title']);
$c = $instance['count'] ? '1' : '0';
$h = $instance['hierarchical'] ? '1' : '0';
$d = $instance['dropdown'] ? '1' : '0';
echo $before_widget;
if ( $title )
echo $before_title . $title . $after_title;
$cat_args = array('orderby' => 'name', 'show_count' => $c, 'hierarchical' => $h);
if ( $d ) {
$cat_args['show_option_none'] = __('Select Category');
wp_dropdown_categories(apply_filters('widget_categories_dropdown_args', $cat_args));
?>
<script type='text/javascript'>
/* <![CDATA[ */
var dropdown = document.getElementById("cat");
function onCatChange() {
if ( dropdown.options[dropdown.selectedIndex].value > 0 ) {
location.href = "<?php echo get_option('home'); ?>/?cat="+dropdown.options[dropdown.selectedIndex].value;
}
}
dropdown.onchange = onCatChange;
/* ]]> */
</script>
<?php
} else {
?>
<ul>
<?php
$cat_args['title_li'] = '';
wp_list_categories(apply_filters('widget_categories_args', $cat_args));
?>
</ul>
<?php
}
echo $after_widget;
}
function update( $new_instance, $old_instance ) {
$instance = $old_instance;
$instance['title'] = strip_tags($new_instance['title']);
$instance['count'] = $new_instance['count'] ? 1 : 0;
$instance['hierarchical'] = $new_instance['hierarchical'] ? 1 : 0;
$instance['dropdown'] = $new_instance['dropdown'] ? 1 : 0;
return $instance;
}
function form( $instance ) {
//Defaults
$instance = wp_parse_args( (array) $instance, array( 'title' => '') );
$title = esc_attr( $instance['title'] );
$count = isset($instance['count']) ? (bool) $instance['count'] :false;
$hierarchical = isset( $instance['hierarchical'] ) ? (bool) $instance['hierarchical'] : false;
$dropdown = isset( $instance['dropdown'] ) ? (bool) $instance['dropdown'] : false;
?>
<p><label for="<?php echo $this->get_field_id('title'); ?>"><?php _e( 'Title:' ); ?></label>
<input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo $title; ?>" /></p>
<p><input type="checkbox" class="checkbox" id="<?php echo $this->get_field_id('dropdown'); ?>" name="<?php echo $this->get_field_name('dropdown'); ?>"<?php checked( $dropdown ); ?> />
<label for="<?php echo $this->get_field_id('dropdown'); ?>"><?php _e( 'Show as dropdown' ); ?></label><br />
<input type="checkbox" class="checkbox" id="<?php echo $this->get_field_id('count'); ?>" name="<?php echo $this->get_field_name('count'); ?>"<?php checked( $count ); ?> />
<label for="<?php echo $this->get_field_id('count'); ?>"><?php _e( 'Show post counts' ); ?></label><br />
<input type="checkbox" class="checkbox" id="<?php echo $this->get_field_id('hierarchical'); ?>" name="<?php echo $this->get_field_name('hierarchical'); ?>"<?php checked( $hierarchical ); ?> />
<label for="<?php echo $this->get_field_id('hierarchical'); ?>"><?php _e( 'Show hierarchy' ); ?></label></p>
<?php
}
}
function my_categories_init()
{
register_sidebar_widget(__('My Categories Widget'), 'MY_Widget_Categories');
}
add_action("plugins_loaded", "my_categories_init");
?>
You’ll need to use
register_widget
rather thanregister_sidebar_widget
, as that function is for the old style widgets (that didn’t extendWP_Widget
or were just functions). You should to do this from a function hooked into thewidgets_init
action. See the WordPress widgets API documentation for more info: http://codex.wordpress.org/Widgets_APIThe following plugin works for me in WP 2.9.
Categories widget with taxonomy/category select dropdown.
I think you can use built-in wp function using this.