How To Create Custom Widgets

WordPress is the most Usable Publishing System I ever use and found, there are so many blogger and internet writer uses WordPress on they blog. WordPress has many free themes and plugins, the other reason is, they add nice featured such as widgets, with WordPress Widgets, we can add anything without touching the themes files, just drag and setting and done

On this WP Tricks, I will show you, how to create Custom Widgets. This tricks written by Darren Hoyt and Ben Gillbanks, and original published on Darren Hyot Blog
Let’s Get Started, first open your functions.php theme and paste or re writes this code

class My_Widget extends WP_Widget {
	function My_Widget() {
		parent::WP_Widget(false, 'Our Test Widget');
	}
function form($instance) {
		// outputs the options form on admin
	}
function update($new_instance, $old_instance) {
		// processes widget options to be saved
		return $new_instance;
	}
function widget($args, $instance) {
		// outputs the content of the widget
	}
}
register_widget('My_Widget');

This code above, only add Example Custom Widget, without some setting and options activated, on the next tricks from Darren Hyot blog, They give example by writing Popular Post widget, let’s do it, below your code above add this code

<?php
class bm_widget_popularPosts extends WP_Widget {

	function bm_widget_popularPosts() {
		parent::WP_Widget(false, 'Popular Posts');
	}

	function widget($args, $instance) {
		$args['title'] = $instance['title'];
		bm_popularPosts($args);
	}

	function update($new_instance, $old_instance) {
		return $new_instance;
	}

	function form($instance) {
		$title = esc_attr($instance['title']);
?>
		<p><label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?> <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo $title; ?>" /></label></p>
<?php
	}
 }
function bm_popularPosts($args = array(), $displayComments = TRUE, $interval = '') {

	global $wpdb;

	$postCount = 5;

	$request = 'SELECT *
		FROM ' . $wpdb->posts . '
		WHERE ';

	if ($interval != '') {
		$request .= 'post_date>DATE_SUB(NOW(), ' . $interval . ') ';
	}

	$request .= 'post_status="publish"
			AND comment_count > 0
		ORDER BY comment_count DESC LIMIT 0, ' . $postCount;

	$posts = $wpdb->get_results($request);

	if (count($posts) >= 1) {

		if (!isset($args['title']) {
			$args['title'] = 'Popular Posts';
		}

		foreach ($posts as $post) {
			wp_cache_add($post->ID, $post, 'posts');
			$popularPosts[] = array(
				'title' => stripslashes($post->post_title),
				'url' => get_permalink($post->ID),
				'comment_count' => $post->comment_count,
			);
		}

		echo $args['before_widget'] . $args['before_title'] . $args['title'] . $args['after_title'];
?>

		<ol>
<?php
		foreach ($popularPosts as $post) {
?>
			<li>
				<a href="<?php echo $post['url'];?>"><?php echo $post['title']; ?></a>
<?php
			if ($displayComments) {
?>
			(<?php echo $post['comment_count'] . ' ' . __('comments', BM_THEMENAME); ?>)
<?php
			}
?>
			</li>
<?php
		}
?>
		</ol>

<?php
		echo $args['after_widget'];
	}
}
?>

And done, you have Popular Post widget and with this similar tricks you can made more sophocated custom widget, such as add Google AdSense widget, Flickr widget, Recent Twitter widgets and Many more