A ProcessWire module to handle API call to a Sendy installation.

ProcessSendApi.php

<?php namespace ProcessWire;

class ProcessSendyAPI extends WireData implements Module, ConfigurableModule
{

    public static function getModuleInfo()
    {
        return array(
            'title' => __('Process Sendy API'),
            'summary' => __('Handle API calls to a Sendy installation'),
            'author' => 'Sérgio Jardim',
            'version' => '001',
            'singular' => true,
            'autoload' => false,
            'icon' => 'envelope'
        );
    }

    /**
     * Data as used by the get/set functions
     *
     */
    protected $data = array();

    /**
     * Default configuration for module
     *
     */
    static public function getDefaultData() {

        return array(
            "sendy_api_key"          => '',
            "sendy_installation_url" => 'http://www.example.com/sendy'
        );
    }

     /**
     * Populate the default config data
     *
     */
    public function __construct() {
       foreach(self::getDefaultData() as $key => $value) {
               $this->$key = $value;
       }
    }

    public static function getModuleConfigInputfields(array $data)
    {
        $data = array_merge(self::getDefaultData(), $data);

        $wrapper = new InputfieldWrapper();

        $f = wire('modules')->get('InputfieldText');
        $f->attr('name', 'sendy_api_key');
        $f->label = __('Sendy API Key', __FILE__);
        $f->description = __('Further instructions at  https://sendy.co/api', __FILE__);
        $f->notes = __('Get your key at http://your_sendy_installation/settings.', __FILE__);
         $f->value = $data['sendy_api_key'];
        $wrapper->add($f);

        $f = wire('modules')->get('InputfieldURL');
        $f->attr('name', 'sendy_installation_url');
        $f->label = __('Sendy instalation URL', __FILE__);
        $f->description = __('Your Sendy installation URL without a trailing slash', __FILE__);
        $f->notes = 'http://www.example.com/sendy';
        $f->value = $data['sendy_installation_url'];
        $wrapper->add($f);

        return $wrapper;
    }

    /**
     * [subscribeUserOrGuest description]
     * @param  [type] $name        [description]
     * @param  [type] $email       [description]
     * @param  [type] $list_id     [description]
     * @param  [type] $success_url [description]
     * @param  [type] $fail_url    [description]
     * @return [type]              [description]
     */
    public function subscribeInSendy($name, $email, $list_id, $success_url = null, $fail_url = null)
    {
        $api_key = $this->data['sendy_api_key'];
        $sendy_url = $this->data['sendy_installation_url'];

        $postdata = http_build_query(
            array(
            'name' => $name,
            'email' => $email,
            'list' => $list_id,
            'boolean' => 'true' //set this to "true" so that you'll get a plain text response
            )
        );
        $opts = array('http' => array('method'  => 'POST', 'header'  => 'Content-type: application/x-www-form-urlencoded', 'content' => $postdata));
        $context  = stream_context_create($opts);
        $result = file_get_contents($sendy_url.'/subscribe', false, $context);

        //check result and redirect
        if($result) {
            $this->wire('log')->save("newsletter", 'A new user subscribed to the site mailing list: '.$email);
            
            if($success_url) {
                header("Location: $success_url");
            }
            
        } else {
            $this->wire('log')->save("error", 'Error occurred on subscribing '.$email);
            
            if($fail_url) {
                header("Location: $fail_url");
            }
        }
    }

}