Kdjykuj

Requirement: every time a customer place an order, a free shipping coupon will be sent which can only be used once.

So I need to insert the dynamic coupon code just like gift card code and abandoned cart rule coupon on normal email template.

Appreciate for any comment and solution.

Yes,it is possible.

• Create A cart rules from admin>Marketing>Cart Rules.


• Create a rules which will create dynamic coupon by selecting 'Use
  Auto Generation' for create multiple couple coupons.

During Creation setting should be :

Now,Add custom data in order email template in Magento 2 and create a coupon of the rule,you should fire run observer at event email_order_set_template_vars_before.

$this->eventManager->dispatch(
'email_order_set_template_vars_before',
['sender' => $this, 'transport' => $transport]
);

So, at this event you can add new parameter via transport to template means you can create coupon and send to email.

Just like:
events.xml

<?xml version="1.0" encoding="utf-8"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">

    <event name="email_order_set_template_vars_before">

        <observer name="add_Custom_variable_to_Order" 

            instance="[Vendor][ModuleName]ObserverObserverforAddCustomVariable" />

    </event>

</config>

And at observer will create coupon and send to to email:

<?php

namespace [Vendor][ModuleName]Observer;

use MagentoFrameworkEventObserverInterface;

use MagentoFrameworkAppRequestDataPersistorInterface;

use MagentoFrameworkAppObjectManager;



class ObserverforAddCustomVariable implements ObserverInterface

{



    protected $ruleFactory



    public function __construct(MagentoSalesRuleModelRuleFactory $ruleFactory) {

        $this->rulesFactory = $ruleFactory;

    }



    /**

     *

     * @param MagentoFrameworkEventObserver $observer

     * @return void

     */

    public function execute(MagentoFrameworkEventObserver $observer)

    {

        /** @var MagentoFrameworkAppActionAction $controller */

        $transport = $observer->getTransport();

        $couponCode = $this->createOneCoupon();

        if($couponCode){

            $transport['free-coupon'] = $couponCode;

        }

    }

        protected function createOneCoupon()

    {

        $ruleModel = $this->ruleFactory->create();

        $ruleModel->load({RulesID});

         try {

                $data = array(

                        'rule_id' => 1,

                        'qty' => 1,

                        'length' => '12',

                        'format' => 'alphanum',

                        'prefix' => 'free-shipping',

                        'suffix' => '',

                        'dash'=>0

                        );





                /** @var $generator MagentoSalesRuleModelCouponMassgenerator */

                $generator = $this->_objectManager->get('MagentoSalesRuleModelCouponMassgenerator');

                if (!$generator->validateData($data)) {

                   return false;

                } else {

                    $generator->setData($data);

                    $generator->generatePool();

                    $generated = $generator->getGeneratedCount();

                    $codes = $generator->getGeneratedCodes();

                    return $codes[0];



                }

            } catch (MagentoFrameworkExceptionLocalizedException $e) {

                $this->_objectManager->get('PsrLogLoggerInterface')->critical($e);

                return false;

            } catch (Exception $e) {



                $this->_objectManager->get('PsrLogLoggerInterface')->critical($e);

                return false;

            }

    }



}

At the email template , you can get this custom variables free-coupon using {{var free-coupon|raw}}.

how to add custom data in order email in magento 2

Working fine.Thanks a lot.Only issue with object manager object.

Just added $objectManager = MagentoFrameworkAppObjectManager::getInstance();

And working fine.

We should not use Object manager to create object.

I did some miner changes in existing code and working fine.
protected $ruleFactory;
protected $massGenerator;

public function __construct(



MagentoSalesRuleModelRuleFactory $ruleFactory,

MagentoSalesRuleModelCouponMassgenerator  $massGenerator



    )

{



$this->rulesFactory = $ruleFactory;

$this->massGenerator = $massGenerator;



}



public function execute(MagentoFrameworkEventObserver $observer)

{

  /** @var MagentoFrameworkAppActionAction $controller */

    $transport = $observer->getTransport();

    $couponCode = $this->createOneCoupon();

    if($couponCode){

        $transport['couponcode'] = $couponCode;

    }



}  





protected function createOneCoupon()

{



     try {

            $data = array(

                    'rule_id' => 4,

                    'qty' => 1,

                    'length' => '12',

                    'format' => 'alphanum',

                    'prefix' => '',

                    'suffix' => '',

                    'dash'=>0

                    );





            if (!$this->massGenerator->validateData($data)) {

               return false;

            } else {

                $this->massGenerator->setData($data);

                $this->massGenerator->generatePool();

                $generated = $this->massGenerator->getGeneratedCount();

                $codes = $this->massGenerator->getGeneratedCodes();

                return $codes[0];



            }

        } catch (MagentoFrameworkExceptionLocalizedException $e) {

            $this->_objectManager->get('PsrLogLoggerInterface')->critical($e);

            return false;

        } catch (Exception $e) {



            $this->_objectManager->get('PsrLogLoggerInterface')->critical($e);

            return false;

        }

}