Create a a text link to a media file (PDF) for a Terms & Conditions checkbox on checkout. #pmpro #pdf

terms-of-service-as-a-link-only.php

<?php
/**
 * This recipe creates a Terms & Conditions checkbox on checkout
 * with a link to the checkout page instead of displaying
 * the Terms & Conditions page content on the page.
 *
 * This recipe requires that "Require Terms of Service on signups?"
 * setting in Membershps > Settings > Advanced settings
 * under "Checkout Settings" is set to "No".
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

// Declare function if it does not already exist.
if ( ! function_exists( 'my_pmprorh_init_require_tos_link' ) ) {
	function my_pmprorh_init_require_tos_link() {

		// Check if Register Helper is active
		if ( ! function_exists( 'pmprorh_add_registration_field' ) ) {
			return;
		}

		// Check that display TOS Setting
		if ( ! empty( pmpro_getOption( 'tospage' ) ) ) {
			return;
		}

		/**
		 * Get the link to the Terms & Conditions.
		 *
		 * To link to an existing page on your site, instead of a media file,
		 * you may replace this line:
		 *
		 * $tos_link = wp_get_attachment_url( 73 ); // Set your media file ID here.
		 *
		 * with this
		 *
		 * $tos_link = get_permalink( 177 ); // Set Terms & Conditions post ID here.
		 */
		$tos_link = wp_get_attachment_url( 73 ); // Set your media file ID here.

		// Create label that displays a link to the Terms & Conditions.
		$label = '&nbsp;&nbsp;&nbsp;&nbsp; I agree to the <a href="' . $tos_link . '" target="_blank" id="my-pmprorh-require-tos-link" class="my-pmprorh-require-tos-link">Terms & Conditions</a>.';

		// Create fields array.
		$fields = array();

		// Terms & Conditions Checkbox field.
		$fields[] = new PMProRH_Field(
			'pmpro_tos_checked',
			'checkbox',
			array(
				'label'          => $label,
				'required'       => true, // make field required
				'memberslistcsv' => true, // include in memberslist csv
				'profile'        => false, // do not display on user profile page
			)
		);

		foreach ( $fields as $field ) {
			pmprorh_add_registration_field( 'before_submit_button', $field );
		}
	}
}

// Add action
if ( ! has_action( 'init', 'my_pmprorh_init_require_tos_link' ) ) {
	add_action( 'init', 'my_pmprorh_init_require_tos_link' );
}

To achieve the same without Register Helper using code for the User Fields class introduced in PMPro core use https://gist.github.com/ipokkel/8dac8389a03f9d663ca3b4b3c6bdbc32