WP plugin to show a single random quote image

quote-images.php

<?php
/*
 * Plugin Name: Quote Images
 * Plugin URI: https://gist.github.com/macbookandrew/7172aef947803f1ac439a352548f382f
 * Description: Quote images with shortcode for random display
 * Version: 1.0.0
 * Author: AndrewRMinion Design
 * Author URI: https://andrewrminion.com
 */

if (!defined('ABSPATH')) {
    exit;
}

// Register Custom Post Type
function quote_image() {

    $labels = array(
        'name'                  => 'Quote Images',
        'singular_name'         => 'Quote Image',
        'menu_name'             => 'Quotes',
        'name_admin_bar'        => 'Quotes',
        'archives'              => 'Quote Image Archives',
        'parent_item_colon'     => 'Parent Quote Image:',
        'all_items'             => 'All Quote Images',
        'add_new_item'          => 'Add New Quote Image',
        'add_new'               => 'Add New',
        'new_item'              => 'New Quote Image',
        'edit_item'             => 'Edit Quote Image',
        'update_item'           => 'Update Quote Image',
        'view_item'             => 'View Quote Image',
        'search_items'          => 'Search Quote Image',
        'not_found'             => 'Not found',
        'not_found_in_trash'    => 'Not found in Trash',
        'featured_image'        => 'Featured Image',
        'set_featured_image'    => 'Set featured image',
        'remove_featured_image' => 'Remove featured image',
        'use_featured_image'    => 'Use as featured image',
        'insert_into_item'      => 'Insert into quote image',
        'uploaded_to_this_item' => 'Uploaded to this quote image',
        'items_list'            => 'Quote Images list',
        'items_list_navigation' => 'Quote Images list navigation',
        'filter_items_list'     => 'Filter quote images list',
    );
    $args = array(
        'label'                 => 'Quote Image',
        'description'           => 'Quote Image',
        'labels'                => $labels,
        'supports'              => array( 'title', 'thumbnail', ),
        'taxonomies'            => array( 'category', 'post_tag' ),
        'hierarchical'          => false,
        'public'                => true,
        'show_ui'               => true,
        'show_in_menu'          => true,
        'menu_position'         => 25,
        'menu_icon'             => 'dashicons-format-quote',
        'show_in_admin_bar'     => true,
        'show_in_nav_menus'     => true,
        'can_export'            => true,
        'has_archive'           => false,
        'exclude_from_search'   => false,
        'publicly_queryable'    => true,
        'capability_type'       => 'page',
    );
    register_post_type( 'quote_image', $args );

}
add_action( 'init', 'quote_image', 0 );

// Add Custom Image Size
function quote_image_size() {
    add_image_size( 'quote', 350, 350 );
}
add_action( 'after_setup_theme', 'quote_image_size' );

// Add Shortcode
function quote_image_shortcode( $atts ) {
    $atts = shortcode_atts( array(
        'id'    => NULL,
    ), $atts, 'quote_iamge');

    // WP_Query arguments
    $args = array(
        'post_type'              => array( 'quote_image' ),
        'post_status'            => array( 'publish' ),
        'nopaging'               => true,
        'posts_per_page'         => '1',
    );

    // Check for specified ID
    if ( $atts['id'] ) {
        $args['p'] = $atts['id'];
    } else {
        $args['orderby'] = 'rand';
    }

    // The Query
    $quote_image_query = new WP_Query( $args );

    // The Loop
    if ( $quote_image_query->have_posts() ) {
        while ( $quote_image_query->have_posts() ) {
            $quote_image_query->the_post();
            return '<div class="quote-image">' . get_the_post_thumbnail( get_the_ID(), 'quote' ) . '</div>';
        }
    }

    // Restore original Post Data
    wp_reset_postdata();
}
add_shortcode( 'quote_image', 'quote_image_shortcode' );

// Move Featured Image Metabox
function quote_image_move_metabox() {
    remove_meta_box( 'postimagediv', 'quote_image', 'side' );
    remove_meta_box( 'wpseo_meta', 'quote_image', 'high' );
    add_meta_box( 'postimagediv', __('Quote Image'), 'post_thumbnail_meta_box', 'quote_image', 'normal', 'high' );
}
add_action('do_meta_boxes', 'quote_image_move_metabox');

// Add Note About Quote Size
function quote_image_note_below_the_title() {
    echo '<p>Quote Images should be at least 350&times;350px.</p>';
}
add_action( 'edit_form_after_title', 'quote_image_note_below_the_title' );

v1.0.0

• Initial plugin