Setting featured image from custom field in wordpress

Question

I have a questions about importing posts in wordpress using csv import. I have mapped the csv like this "post_title" "post_content" "featured_image"etc. All the post were imported but the featured image is not showing.

The featured image url is showing in the custom field only. My question is,How do I get the featured image to show? as I have hundreds of posts, I can not edit them manually.

Emil Emil · Accepted Answer · 2018-10-13T15:51:07

I had the same problem – I had custom fields on several posts that contained URLs which I wanted to use for featured images. I knew some of the images were already in my media library, so I made the following functions to add an Bulk Edit-action to the editor window, which looped over the posts and uploaded images where the image wasn't in the library already, or got the ID of the image already in the library, and then set that as the new featured image for the post.

It's a rough code, but it works fine – please back up your site before doing this though.

function does_file_exists($filename) {
    global $wpdb;
    $data = $wpdb->get_results( "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_value LIKE '%/$filename'" );
    foreach ($data as $ID){
        $ID = $ID->post_id;
        if (get_post_type($ID) == "attachment"){
            return $ID;
        }
    }
    return null;
}

function upload_image_from_URL($image_url, $post_id){
    // Add Featured Image to Post
    $image_name       = pathinfo($image_url)['basename'];
    $upload_dir       = wp_upload_dir(); // Set upload folder
    $image_data       = file_get_contents($image_url); // Get image data
    $unique_file_name = wp_unique_filename( $upload_dir['path'], $image_name ); // Generate unique name
    $filename         = basename( $unique_file_name ); // Create image file name

    // Check folder permission and define file location
    if( wp_mkdir_p( $upload_dir['path'] ) ) {
        $file = $upload_dir['path'] . '/' . $filename;
    } else {
        $file = $upload_dir['basedir'] . '/' . $filename;
    }

    // Create the image  file on the server
    file_put_contents( $file, $image_data );

    // Check image file type
    $wp_filetype = wp_check_filetype( $filename, null );

    // Set attachment data
    $attachment = array(
        'post_mime_type' => $wp_filetype['type'],
        'post_title'     => sanitize_file_name( $filename ),
        'post_content'   => '',
        'post_status'    => 'inherit'
    );

    // Create the attachment
    $attach_id = wp_insert_attachment( $attachment, $file, $post_id );

    // Include image.php
    require_once(ABSPATH . 'wp-admin/includes/image.php');

    // Define attachment metadata
    $attach_data = wp_generate_attachment_metadata( $attach_id, $file );

    // Assign metadata to attachment
    wp_update_attachment_metadata( $attach_id, $attach_data );
    return $attach_id;
}

function set_featured_image($post_id){
    if (wp_is_post_revision($post_id)) return;
    if (has_post_thumbnail($post_id)) return;

    $image_url = get_field('FIELD_NAME', $post_id);

    if ($image_url){        
        $attachment_ID = does_file_exists(pathinfo($image_url)['basename']);
        $attachment_ID = ($attachment_ID ? $attachment_ID : upload_image_from_URL($image_url, $post_id));

        if ($attachment_ID){
            $message = "Setting attachment ". $attachment_ID ." to post ". $post_id;
            error_log($message);
            set_post_thumbnail($post_id, $attachment_ID);
        }
    }
}

add_filter( 'bulk_actions-edit-post', 'register_bulk_update_featured_image' );
function register_bulk_update_featured_image($bulk_actions) {
    $bulk_actions['update_featured_image'] = "Get featured image from field";
    return $bulk_actions;
}

add_filter( 'handle_bulk_actions-edit-post', 'bulk_update_featured_image', 10, 3 );
function bulk_update_featured_image( $redirect_to, $doaction, $post_ids ) {
    if ( $doaction !== 'update_featured_image' ) {
        return $redirect_to;
    }
    foreach ( $post_ids as $post_id ) {
        // Perform action for each post.
        set_featured_image($post_id);
    }
    $redirect_to = add_query_arg( 'bulk_updated_featured_images', count( $post_ids ), $redirect_to );
    return $redirect_to;
}

add_action( 'admin_notices', 'my_bulk_action_admin_notice' );
function my_bulk_action_admin_notice() {
    if ( ! empty( $_REQUEST['bulk_updated_featured_images'] ) ) {
        $id_count = intval( $_REQUEST['bulk_updated_featured_images'] );
        printf('<div id="message" class="updated fade">Updated %s featured images.</div>',
            $id_count);
    }
}

Setting featured image from custom field in wordpress

2 Answers