WordPress Sample Widget

widget.php

<?php
/**
 * Widget Name: Company WidgetName Widget
 * Description: A sample widget.
 */

class Company_WidgetName_Widget extends WP_Widget {
    /**
    * Register widget with WordPress.
    */
    public function __construct() {
        parent::__construct(
            'company_widgetname_widget', // Widget ID
            __('Company WidgetName', 'text-domain'), // Widget Name
            array( 'description' => __('A sample widget.', 'text-domain'), ) // Widget Descriptions
        );
    }

    /**
     * Back-end widget form.
     * @param array $instance Previously saved values from database.
     */
    public function form($instance) {
        $defaults = array( 'title' => __('Title', 'text-domain'));
        $instance = wp_parse_args($instance, $defaults); ?>

        <p>
            <label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:', 'text-domain'); ?></label>
            <input type="text" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" value="<?php echo $instance['title']; ?>" class="widefat" />
        </p>

        <?php
    }

    /**
     * Front-end display of widget.
     * @param array $args Widget arguments.
     * @param array $instance Saved values from database.
     */
    public function widget($args, $instance) {
        extract($args);
        $title = apply_filters('widget_title', $instance['title']);
        echo $before_widget;

        if ($title) {
            echo $before_title . $title . $after_title;
        } ?>
			<ul class="list-unstyled">
               
			</ul>

	    <?php echo $after_widget;
    }

    /**
     * Sanitize widget form values as they are saved.
     * @param array $new_instance Values just sent to be saved.
     * @param array $old_instance Previously saved values from database.
     * @return array Updated safe values to be saved.
     */
    public function update($new_instance, $old_instance) {
        $instance = array();
        //The strip_tags() function strips a string from HTML, XML, and PHP tags.
        $instance['title'] = strip_tags($new_instance['title']);
        return $instance;
    }
}

// function to register popular post widget
add_action('widgets_init', function () {
    register_widget('company_widgetname_widget');
});