wp-learn-dashboard-widgets.php

<?php
/**
 * Plugin Name: WP Learn Dashboard Widgets
 * Description: A plugin to add a widget to the dashboard 
 */

add_action('wp_dashboard_setup', 'wp_learn_dashboard_widget_callback');

function wp_learn_dashboard_widget_callback(){
    if (!current_user_can('manage_options')) {
        return;
    }
    wp_add_dashboard_widget(
        'wp_learn_dashboard_widget_id',
        'WP Learn Dashboard Widget',
        'wp_learn_dashboard_widget_content_callback',
        'wp_learn_dashboard_widget_control_callback',
        array(
            'content' => 'This is a list of your most recent posts',
        ),
    );
}

function wp_learn_dashboard_widget_content_callback( $screen, $widget_args ){
    $number_posts = get_option( 'wp_learn_dashboard_widget_numberposts', 5 );
    $post_args = array(
        'numberposts' => $number_posts,
        'post_status' => 'publish'
    );
    $recent_posts = wp_get_recent_posts( $post_args );
    echo '<h3>' . $widget_args['args']['content'] . '</h3>';
    echo '<ul>';
    foreach( $recent_posts as $recent_post ){
        echo '<li><a href="' . get_permalink( $recent_post['ID'] ) . '">' . $recent_post['post_title'] . '</a></li>';
    }
    echo '</ul>';
}

function wp_learn_dashboard_widget_control_callback(){
    if (isset($_POST['wp_learn_dashboard_widget_numberposts'])){
        update_option( 'wp_learn_dashboard_widget_numberposts', sanitize_text_field( $_POST['wp_learn_dashboard_widget_numberposts'] ) );
    }
    $number_posts = get_option( 'wp_learn_dashboard_widget_numberposts', 5 );
    echo '<label>Enter number of posts to display</label>';
    echo '<input type="text" name="wp_learn_dashboard_widget_numberposts" value='.$number_posts.' />';
}