Attach a PDF to the WooCommerce order email

In this tutorial, I’ll show you how to upload a PDF file for each product in WooCommerce and have that file automatically attached to the new order email sent to the customer.

Add a PDF upload field to the product editor

We’ll use add_meta_boxto add a file input in the product edit screen:

<?php
add_action( 'add_meta_boxes', 'addProductPdfUploadBox' );
function addProductPdfUploadBox() {
    add_meta_box(
        'productPdfMeta',
        'Customer PDF File',
        'renderProductPdfMetaBox',
        'product',
        'side'
    );
}

function renderProductPdfMetaBox( $post ) {
    wp_nonce_field( 'saveProductPdfMeta', 'productPdfMetaNonce' );
    $pdfUrl = get_post_meta( $post->ID, '_productPdfUrl', true );

    echo '<input type="file" name="productPdfFile" accept="application/pdf" />';
    if ( $pdfUrl ) {
        echo '<p><a href="' . esc_url( $pdfUrl ) . '" target="_blank">View current PDF</a></p>';
    }
}

Save the uploaded PDF file when saving the product

The uploaded file is saved in the uploadsfolder and its URL is stored in post meta:

<?php
add_action( 'save_post', 'saveProductPdfMeta' );
function saveProductPdfMeta( $postId ) {
    if ( ! isset( $_POST['productPdfMetaNonce'] ) || 
         ! wp_verify_nonce( $_POST['productPdfMetaNonce'], 'saveProductPdfMeta' ) ) {
        return;
    }

    if ( isset( $_FILES['productPdfFile'] ) && $_FILES['productPdfFile']['error'] === UPLOAD_ERR_OK ) {
        require_once ABSPATH . 'wp-admin/includes/file.php';

        $uploadedFile = wp_handle_upload( $_FILES['productPdfFile'], [ 'test_form' => false ] );

        if ( isset( $uploadedFile['url'] ) ) {
            update_post_meta( $postId, '_productPdfUrl', esc_url_raw( $uploadedFile['url'] ) );
        }
    }
}

Attach the PDF to the new order email

We use the woocommerce_email_attachmentsfilter to add the PDF file to the customer new order email:

<?php
add_filter( 'woocommerce_email_attachments', 'attachProductPdfsToEmail', 10, 4 );
function attachProductPdfsToEmail( $attachments, $emailId, $order, $email ) {
    if ( $emailId !== 'customer_processing_order' ) {
        return $attachments;
    }

    foreach ( $order->get_items() as $item ) {
        $productId = $item->get_product_id();
        $pdfUrl    = get_post_meta( $productId, '_productPdfUrl', true );

        if ( $pdfUrl ) {
            $uploadDir = wp_upload_dir();
            $filePath  = $uploadDir['basedir'] . str_replace( $uploadDir['baseurl'], '', $pdfUrl );

            if ( file_exists( $filePath ) ) {
                $attachments[] = $filePath;
            }
        }
    }

    return $attachments;
}

What does this do?

• You can upload a PDF file per product from the admin.
• That PDF will be automatically attached to the customer’s new order email if the product is purchased.
• Files are stored in the uploads folder and are not publicly indexed unless someone has the direct link.

Related posts:

Adjuntar PDF al email del pedido en WooCommerce How to create an order in WooCommerce via REST API Rename the “Place Order” button text based on the payment gateway in WooCommerce How to modify an order in WooCommerce using code