Top/Popular post by Google analytics in WordPress

class-top-post-widget.php

<?php
/**
 * This widget is depend on https://wordpress.org/plugins/google-analytics-post-pageviews/
 *
 * Steps: 
 * 1. Create a Google developer project - http://console.developers.google.com/
 *
 * 2.enable google analytics service, you can check 
 *  - https://www.youtube.com/watch?v=AX9PtgKPnuM, 
 *  - https://developers.google.com/ad-exchange/rtb/open-bidder/google-app-guide
 * 
 * 3. Get Client ID and secret key  
 *
 * 4. activate and setup https://wordpress.org/plugins/google-analytics-post-pageviews/ 
 *
 * 5. check widget section for Top Post Widget
 */

/**
 * The base widget for Showing Top post by Google analytics
 *
 */
class TopPostWidget extends WP_Widget {

	private $popPosts;

	/**
	 * Sets up the widget
	 *
	 * @since 0.1
	 */
	public function __construct() {

		parent::__construct(
			'gd-analytic-top-posts', // Base ID
			__( 'Top Posts', 'largo' ), // Name
			array( 'description' => __( 'List Top posts', 'largo' ), ) // Args
		);
	}

	/**
	 * Output the widget
	 *
	 *
	 * @param array $args
	 * @param array $instance
	 */
	function widget( $args, $instance ) {
		extract( $args );

		$title = apply_filters( 'widget_title', empty( $instance['title'] ) ? __( 'Recent ' . $posts_term, 'largo') : $instance['title'], $instance );

		/*
		 * Start drawing the widget
		 */
		echo $before_widget;

		if ( $title ) {
			echo $before_title . $title . $after_title;
		}

		$args = array(
			'post_type' => 'post',
			'orderby'   => 'meta_value_num',
			'meta_key'  => '_gapp_post_views',
		);
		$num_posts = ( isset( $instance['num_posts'] ) && !empty( $instance['num_posts'] ) )? $instance['num_posts']: 5;
		if( isset( $num_posts ) && !empty( $num_posts ) && $num_posts > 1 ){
			$args['posts_per_page'] = $num_posts;
		}
		$the_query = new WP_Query( $args ); 
		if ( $the_query->have_posts() ){
			echo '<div class="top-post-container">';
			while ( $the_query->have_posts() ) {
				$the_query->the_post();	
				echo '<div class="gd-toppost-item">';
					echo '<div class="left">';
						if (has_post_thumbnail( ) ){
							echo get_the_post_thumbnail( get_the_ID(), array( 160, 100 ) );
						} else{
              $image = 'http://defaultimage...com';
							echo '<img src="' . $image . '" width="160" height="100" >';
						}
					echo '</div>';
					echo '<div class="right">';
						$top_post_categories = get_the_category( );
						if( !empty( $top_post_categories ) ){
							echo '<ul>';
							foreach( $top_post_categories as $top_post_category ) {
								if( isset( $top_post_category->name )){
									$category_link = get_category_link( $top_post_category->term_id );
									echo '<li><a href="' . $category_link . '">' . $top_post_category->name . '</a></li>';
								}
							}
							echo '</ul>';
						}
						echo '<a href="'. get_permalink().'">'. get_the_title() .'</a>';
					echo '</div>';
				echo '</div>';
			} 
			echo '</div>';
		}
		wp_reset_postdata(); 
		echo $after_widget;
	}

	/**
	 * Outputs the options form on admin
	 *
	 * @param array $instance The widget options
	 */
	public function form( $instance ) {

		$defaults = array(
			'title' => __('popular', 'largo'),
			'num_posts' => 5,
		);
		$instance = wp_parse_args( (array) $instance, $defaults );
		?>

		<p>
			<label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:', 'largo' ); ?></label>
			<input id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" value="<?php echo $instance['title']; ?>" style="width:90%;" />
		</p>

		<p>
			<label for="<?php echo $this->get_field_id( 'num_posts' ); ?>"><?php _e( 'Number of posts to show:', 'largo' ); ?></label>
			<input id="<?php echo $this->get_field_id( 'num_posts' ); ?>" name="<?php echo $this->get_field_name( 'num_posts' ); ?>" value="<?php echo $instance['num_posts']; ?>" style="width:90%;" type="number"/>
		</p>

	<?php
	}

	/**
	 * Processing widget options on save
	 *
	 * @param array $new_instance The new options
	 * @param array $old_instance The previous options
	 */
	public function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		$instance['title'] = sanitize_text_field( $new_instance['title'] );
		$instance['num_posts'] = intval( $new_instance['num_posts'] );
		return $instance;
	}
}

add_action( 'widgets_init', function(){
	register_widget( 'TopPostWidget' );
});