JezK

Edit File: class-ninja-forms.php

<?php

defined('ABSPATH') or exit;

/**
 * Class MC4WP_Ninja_Forms_Integration
 *
 * @ignore
 */
class MC4WP_Ninja_Forms_Integration extends MC4WP_Integration
{
    /**
     * @var string
     */
    public $name = 'Ninja Forms';

/**
     * @var string
     */
    public $description = 'Subscribe visitors from your Ninja Forms forms.';

/**
     * Add hooks
     */
    public function add_hooks()
    {
        add_action('mc4wp_integration_ninja_forms_subscribe', [ $this, 'subscribe_from_ninja_forms' ], 10, 7);
    }

public function subscribe_from_ninja_forms($email_address, $merge_fields, $list_id, $double_optin = true, $update_existing = false, $replace_interests = false, $form_id = 0)
    {
        // set options from parameters (coming from action)
        $orig_options                       = $this->options;
        $this->options['double_optin']      = $double_optin;
        $this->options['update_existing']   = $update_existing;
        $this->options['replace_interests'] = $replace_interests;
        $this->options['lists']             = [ $list_id ];

$data          = $merge_fields;
        $data['EMAIL'] = $email_address;

$this->subscribe($data, $form_id);

// revert to original options
        $this->options = $orig_options;
    }

/**
     * @return bool
     */
    public function is_installed()
    {
        return class_exists('Ninja_Forms');
    }

/**
     * @since 3.0
     * @return array
     */
    public function get_ui_elements()
    {
        return [];
    }

/**
     * @param int $form_id
     * @return string
     */
    public function get_object_link($form_id)
    {
        return '<a href="' . admin_url(sprintf('admin.php?page=ninja-forms&form_id=%d', $form_id)) . '">Ninja Forms</a>';
    }
}