How to not display subcategories in Recent Posts widget area?

Question

I'm relatively new to Wordpress, and coding in general. I am trying to edit theme-specific recent posts widget to display only posts within a certain category. Currently, the theme will display recent posts with video thumbnails in a category, but it will also include recent posts within any subcategories of that category. I do not want to display posts that appear in subcategories of that category. Can this be done? The code is below.

Widget-home-posts file to categorize:

function widget( $args, $instance ) {
    extract( $args );

    // If user have not selected any category then display none.
    if ( empty( $instance['cat'] ) ) {
        return;
    }

    // Output the theme's $before_widget wrapper.
    echo $before_widget;

        // Pull the selected category.
        $cat_id = $instance['cat'];

        // Get the category.
        $category = get_category( $cat_id );

        // Get the category archive link.
        $cat_link = get_category_link( $cat_id );

        // Posts query arguments.
        $args = array(
            'post_type'      => 'post',
            'posts_per_page' => 3
        );

        // Limit to category based on user selected tag.
        if ( ! empty( $instance['cat'] ) ) {
            $args['cat'] = $instance['cat'];
        }

        // Allow dev to filter the post arguments.
        $query = apply_filters( 'videoz_home_recent_args', $args );

        // The post query.
        $posts = new WP_Query( $query );

Recent posts widget code:

 class VideoZ_Recent_Widget extends WP_Widget {

/**
 * Sets up the widgets.
 *
 * @since 1.0.0
 */
function __construct() {

    // Set up the widget options.
    $widget_options = array(
        'classname'   => 'widget-videoz-recent posts-thumbnail-widget',
        'description' => __( 'Display recent posts with thumbnails.', 'videoz' )
    );

    // Create the widget.
    parent::__construct(
        'videoz-recent',                                   // $this->id_base
        __( '» Recent Posts Thumbnails', 'videoz' ), // $this->name
        $widget_options                                      // $this->widget_options
    );

    // Flush the transient.
    add_action( 'save_post'   , array( $this, 'flush_widget_transient' ) );
    add_action( 'deleted_post', array( $this, 'flush_widget_transient' ) );
    add_action( 'switch_theme', array( $this, 'flush_widget_transient' ) );

}

/**
 * Outputs the widget based on the arguments input through the widget controls.
 *
 * @since 1.0.0
 */
function widget( $args, $instance ) {
    extract( $args );

    // Output the theme's $before_widget wrapper.
    echo $before_widget;
if ( $instance['title'] ) {
        echo $before_title . apply_filters( 'widget_title', $instance['title'], $instance, $this->id_base ) . $after_title;
    }
    // Display the recent posts.
        if ( false === ( $recent = get_transient( 'videoz_recent_widget_' . $this->id ) ) ) {

        // Posts query arguments.
        $args = array(
            'post_type'      => 'post',
            'posts_per_page' => $instance['limit']
        );

        // The post query
        $recent = get_posts( $args );

        // Store the transient.
        set_transient( 'videoz_recent_widget_' . $this->id, $recent );

    }

    global $post;
    if ( $recent ) {
        echo '<ul>';

            foreach ( $recent as $post ) :
                setup_postdata( $post );

                echo '<li>';
                    echo '<a class="entry-thumbnail" href="' . esc_url( get_permalink( $post->ID ) ) . '" rel="bookmark">' . get_the_post_thumbnail( $post->ID, 'videoz-widget', array( 'class' => 'entry-thumb', 'alt' => esc_attr( get_the_title( $post->ID ) ) ) ) . '<span class="play-button"><i class="fa fa-play"></i></span></a>';
                    echo '<a href="' . esc_url( get_permalink( $post->ID ) ) . '" rel="bookmark">' . esc_attr( get_the_title( $post->ID ) ) . '</a>';
                    if ( $instance['show_date'] ) :
                        echo '<time class="entry-date" datetime="' . get_the_date( 'c' ) . '">' . get_the_date() . '</time>';
                    endif;
                echo '</li>';

            endforeach;

        echo '</ul>';
    }

    // Reset the query.
    wp_reset_postdata();

Answer 1

You need to pass more query arguments. In this case you need:

    $args = array(
        'post_type'      => 'post',
        'posts_per_page' => $instance['limit'],
        'category__in'   => $id
    );

Where $id is the category id, not the post id.