Checkout custom terms/conditions modal

add_action( 'woocommerce_after_checkout_form', function() {

	$page = get_page_by_title( 'Terms and Conditions' ); 
	$content = apply_filters( 'the_content', $page->post_content );

	printf( '<div id="customModal" style="display: none;">%s</div>', $content );	

} );
add_action( 'wp_enqueue_scripts', function() {

	if( ! is_checkout() ) {
		return;
	}

	wp_enqueue_script( 'jquery' );
	wp_enqueue_script( 'jquery-ui-core' );
	wp_enqueue_script( 'jquery-ui-dialog' );

	wp_enqueue_style( 'wp-jquery-ui-dialog' );

	wp_add_inline_script( 'jquery', "

		jQuery( document ).ready( function( $ ) {

			var checkout_form = $( 'form.checkout' );
			checkout_form.on( 'checkout_place_order', function( event ) {

				if( $( 'input#terms' ).is( ':checked' ) ) { return true; }

				$( '#customModal' ).dialog( {
					resizable: true, height: 600, width: 600, modal: true,
					buttons: {
						'I Agree to the Terms and Conditions': function() {
							$( 'input#terms' ).prop( 'checked', true );
							$( this ).dialog( 'close' );
							checkout_form.submit();
						},
						Cancel: function() {
							$( this ).dialog( 'close' );
						}
					}
				} );

				return false;

			} );

		} );

	" );

} );