Developer Challenge: Create a Custom WordPress Widget | subscribe for more at https://www.ibenic.com/newsletter/

widget-recent-posts.php

<?php

/**
 * Plugin Name: Recent Widget Challenge from ibenic.com/newsletter
 */

/*
You will create a custom WordPress widget that displays a list of the most recent posts.

Each recent post should have:
- Title
- Thumbnail
- Excerpt

The widget should have a title that can be customized by the user.

Extra Credit:
- Show the number of comments for each post.
- In the admin area, add a "Number of posts" field. If it's set to 3, it will show 3 recent posts.
*/

class Recent_Posts_Widget extends WP_Widget {

 function __construct() {
  parent::__construct(
  // Base ID of your widget
      'recent_posts_widget',

      // Widget name will appear in UI
      __('Recent Posts Widget', 'recent_posts_widget_domain'),

      // Widget description
      array( 'description' => __( 'A custom widget that displays a list of the most recent posts with thumbnails', 'recent_posts_widget_domain' ), )
  );
 }

 // Creating widget front-end
 public function widget( $args, $instance ) {
  $title = apply_filters( 'widget_title', $instance['title'] );

  // before and after widget arguments are defined by themes
  echo $args['before_widget'];
  if ( ! empty( $title ) )
   echo $args['before_title'] . $title . $args['after_title'];

  // This is where you run the code and display the output
  $this->get_recent_posts( $instance );

  echo $args['after_widget'];
 }

 // Widget Backend
 public function form( $instance ) {
  if ( isset( $instance[ 'title' ] ) ) {
   $title = $instance[ 'title' ];
  } else {
   $title = __( 'New title', 'recent_posts_widget_domain' );
  }

  if ( isset( $instance[ 'number' ] ) ) {
   $number = $instance[ 'number' ];
  } else {
   $number = 5;
  }
  // Widget admin form
  ?>
  <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 esc_attr( $title ); ?>" />
  </p>
  <p>
   <label for="<?php echo $this->get_field_id( 'number' ); ?>"><?php _e( 'Number of posts:' ); ?></label>
   <input class="widefat" id="<?php echo $this->get_field_id( 'number' ); ?>" name="<?php echo $this->get_field_name( 'number' ); ?>" type="number" value="<?php echo esc_attr( $number ); ?>" />
  </p>
  <?php
 }

 // Updating widget replacing old instances with new
 public function update( $new_instance, $old_instance ) {
  $instance = array();
  $instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';
  $instance['number'] = ( ! empty( $new_instance['number'] ) ) ? absint( $new_instance['number'] ) : 5;

  return $instance;
 }

 // Get the most recent posts with thumbnails
 private function get_recent_posts( $args ) {
  $args = array(
      'posts_per_page' => isset( $args['number'] ) ? absint( $args['number'] ) : 5,
      'post_type' => 'post',
      'orderby' => 'date',
      'order' => 'DESC'
  );

  $posts = get_posts( $args );
  if ( $posts ) {
   echo '<ul>';
   foreach ( $posts as $post  ) {
    $number = get_comments_number( $post );
    echo '<li><a href="' . get_permalink( $post ) . '">' . get_the_post_thumbnail( $post ) . get_the_title( $post ) . ' (' . $number . ')</a></li>';
   }
   echo '</ul>';
  }

 }
}


// Register and load the widget
function recent_posts_widget_load() {
 register_widget( 'Recent_Posts_Widget' );
}
add_action( 'widgets_init', 'recent_posts_widget_load');