Accept PayPal with UI components

Use Unzer UI component to add Unzer PayPal payment to your checkout page.

Overview

Using UI components for PayPal you get a ready-made form with the fields necessary to make this type of payment. You can check a demo version of the component here. Basic steps for integrating using UI components are the same for all payment methods and you can read about them here.

Before you begin

• Check the basic integration requirements.
• Familiarize yourself with general guide on integrating using UI components.

Step 1: Add UI components to your payment page

client side

First, you need to initiate our UI components library and add the payment form to your payment page.

Initiate UI component

Load our JS script and CSS stylesheet

Include Unzer’s script and stylesheet on your website.

Always load the script and stylesheet directly from Unzer:

<link rel="stylesheet" href="https://static.unzer.com/v1/unzer.css" />
<script type="text/javascript" src="https://static.unzer.com/v1/unzer.js"></script>

Faster load time
To make your website load faster, insert JavaScript scripts at the bottom of your HTML document.

Importing Unzer styles
To minimize the risk of Unzer styles affecting the styles of your webpage, we suggest putting unzer.css on top of other imported CSS files.

Create an Unzer instance

Create an unzer instance with your public key:

// Creating an unzer instance with your public key
var unzerInstance = new unzer('s-pub-xxxxxxxxxx');

Placeholder keys
In the previous example, we used a placeholder API key for example purposes. You should replace it with your public key.

Localization and languages

We support localization with locale option parameters. Check the Localization page for a list of all the supported locales.

The auto option (applied by default) uses the client’s browser language.

Here you can see how to set the language, in our case ‘de-DE’ - to do so, add a comma separated parameter to your unzer instance:

// Creating an unzer instance with your public key
var unzerInstance = new unzer('s-pub-xxxxxxxxxx', {locale: 'de-DE'});

Implement the payment form

To securely collect payment data from your customer, you need to create a payment form with empty DOM elements and unique ID’s within them. That way unzer.js will know where to place its UI components.

<form id="payment-form" class="unzerUI form" novalidate>
    <div id="example-PayPal" class="field"></div>
    <button class="unzerUI primary button fluid" id="submit-button" type="submit">Pay</button>
</form>

<form id="payment-form" class="unzerUI form" novalidate>
    <button class="unzerUI primary button fluid" id="submit-button" type="submit">Pay</button>
</form>

Matching IDs

When choosing your ID for a UI component, make sure that the names in your HTML and JavaScript match.

For example:

<div id="example-PayPal"> matches containerId: "example-PayPal".

Create a payment type resource

To create a payment type resource – a PayPal instance, call the unzerInstance.PayPal() method:

// Creating a PayPal instance
var paypal = unzerInstance.Paypal()

// Rendering input field
paypal.create('email', {
  containerId: 'example-PayPal'
});

// Creating a PayPal instance
var paypal = unzerInstance.Paypal()

Add an event listener for “submit” of the form.

Inside, create a Promise on the Paypal object. The Promise gets either resolved or rejected:

let form = document.getElementById('payment-form');
form.addEventListener('submit', function(event) {
    event.preventDefault();

    paypal.createResource()
        .then(function(result) {
            // Submit the id of the created payment type to your
            // backend to perform the payment transaction with it.
            typeId = result.id;
        })
        .catch(function(error) {
            // handle errors
            document.getElementById('error-holder').innerText = error.customerMessage || error.message || 'Error'
        })
});

Optional: Customize the UI components

You can customize the font of the forms by changing the options within the create method. Here you can set the following styles: fontSize, fontColor and fontFamily.

paypal.create('email', {
    containerId: 'example-PayPal',
    fontSize: '16px',
    fontColor: 'lightgrey',
    fontFamily: 'Arial, Helvetica, sans-serif',
    Helvetica, sans-serif'
});

Step 2: Make a payment

server side

Option 1: Make a charge transaction

Now, make a charge transaction with the Paypal typeId that you created and the returnUrl leading back to your shop after the payment is finished on the external page. With the charge transaction, an amount is reserved but is not yet transferred. Initially the transaction is pending and a payment resource is created.

POST https://api.unzer.com/v1/payments/charges
   
{
  "amount" : "20",
  "currency": "EUR",
  "returnUrl": "https://www.my-shop-url.de/returnhandler",
  "resources" : {
    "typeId" : "s-ppl-jldsmlmiprwe"
  }
}

$unzer     = new UnzerSDK\Unzer('s-priv-xxxxxxxxxx');

$chargeInstance = new Charge(100.00, 'EUR', $returnUrl);
$typeId = 's-ppl-jldsmlmiprwe';
$transaction = $unzer->performCharge($chargeInstance, $typeId);

Unzer unzer = new Unzer("s-priv-xxxxxxxxxx");
Charge charge = unzer.charge(BigDecimal.ONE, Currency.getInstance("EUR"), "s-ppl-jldsmlmiprwe", new URL("https://www.my-shop-url.de/returnhandler"));

The response looks similar to the following example:

{
    "id": "s-chg-1",
    "isSuccess": false,
    "isPending": true,
    "isError": false,
    "redirectUrl": "https://payment.unzer.com/v1/redirect/ppl/s-sGYdGywWpxzW",
    "message": {
        "code": "COR.000.100.112",
        "merchant": "Request successfully processed in 'Merchant in Connector Test Mode'",
        "customer": "Your payments have been successfully processed in sandbox mode."
    },
    "amount": "20.0000",
    "currency": "EUR",
    "returnUrl": "https://www.my-shop-url.de/returnhandler",
    "date": "2021-05-10 00:51:03",
    "resources": {
        "paymentId": "s-pay-131937",
        "traceId": "70ddf3152a798c554d9751a6d77812ae",
        "typeId": "s-ppl-jldsmlmiprwe"
    },
    "paymentReference": "",
    "processing": {
        "uniqueId": "31HA07BC8157BD2BC04D483EFA914465",
        "shortId": "4845.3426.1987",
        "traceId": "70ddf3152a798c554d9751a6d77812ae"
    }
}

For a full description of the charge transaction, refer to the relevant server-side integration documentation page: Charge a payment (direct API calls), Charge a payment (PHP SDK), Charge a payment (Java SDK).

Forward the customer to the external payment page

After you charge the PayPal resource, implement the following flow:

1. Redirect the customer to the redirectUrl returned in the response to your charge request
2. The customer is forwarded to the PayPal payment page.
3. After a successful payment or abort on the PayPal page, the customer is redirected to the returnUrl specified in the initial charge call.

Option 2: Make an authorize transaction

You can also make an authorize transaction instead with the Paypal typeId that you created and the returnUrl leading back to your shop after the payment is finished on the external page. Initially the transaction will be pending and a payment resource is created. With the authorize transaction an amount is reserved but is not yet transferred. You will need to charge the payment at a later point.

POST https://api.unzer.com/v1/payments/authorize
   
{
  "amount" : "20",
  "currency": "EUR",
  "returnUrl": "https://www.my-shop-url.de/returnhandler",
  "resources" : {
    "typeId" : "s-ppl-jldsmlmiprwe"
  }
}

$unzer     = new UnzerSDK\Unzer('s-priv-xxxxxxxxxx');

$chargeInstance = new Charge(100.00, 'EUR', $returnUrl);
$transaction = $unzer->performAuthorization($chargeInstance, $typeId);

Unzer unzer = new Unzer("s-priv-xxxxxxxxxx");
Charge charge = unzer.charge(BigDecimal.ONE, Currency.getInstance("EUR"), "s-ppl-0ajzmaxcuvhc", new URL("https://www.my-shop-url.de/returnhandler"));

For a full description of the Authorize transaction, see the relevant server-side-integration documentation page: Authorize a payment (direct API calls), Authorize a payment (PHP SDK), Authorize a payment (Java SDK).

Charge the authorization

Because the customer already accepted the payment with the authorize transaction, you can now charge the payment to transfer the money.

When you authorize before charge, the authorized amount is on hold for 29 days. Paypal however, recommends to charge the funds within the three-day honor period. The success of the charge is subject to risk and availability of funds on the authorized payment instrument.

POST https://api.unzer.com/v1/payments/s-pay-1/charges
   
{
  "amount": 20,
  "paymentReference": "Test charge transaction"
}

$unzer = new Unzer('s-priv-xxxxxxxxx');
$charge = $unzer->performChargeOnPayment('s-pay-1', new Charge());

Unzer unzer = new Unzer("s-priv-xxxxxxxxxx");
Charge charge = unzer.chargeAuthorization("s-pay-1");

The response looks similar to the following example:

{
    "id": "s-chg-1",
    "isSuccess": true,
    "isPending": false,
    "isError": false,
    "message": {
        "code": "COR.000.100.112",
        "merchant": "Request successfully processed in 'Merchant in Connector Test Mode'",
        "customer": "Your payments have been successfully processed in sandbox mode."
    },
    "amount": "20.0000",
    "currency": "EUR",
    "date": "2021-06-04 15:33:16",
    "resources": {
        "customerId": "s-cst-d6ae94482612",
        "paymentId": "s-pay-1",
        "basketId": "",
        "metadataId": "",
        "payPageId": "",
        "traceId": "4ebfbfcae640ff2823e2e65febd54037",
        "typeId": "s-ppl-4x3zn7i4bxyh"
    },
    "paymentReference": "Test charge transaction",
    "processing": {
        "uniqueId": "31HA07BC8198C2F9107E38AF14C45201",
        "shortId": "4867.4719.2103",
        "traceId": "4ebfbfcae640ff2823e2e65febd54037"
    }
}

Step 3: Check status of the payment

server side

Once the customer is redirected to the returnUrl, you can fetch the payment details from the API, by using the resources.paymentId from the Charge response above to handle the payment according to its status. If the status of the payment is completed , the payment process has been finished successfully and can be considered as paid. Check all possible payment states here.

GET https://api.unzer.com/v1/payments/{payment_ID}

{
    "id": "s-pay-131937",
    "state": {
        "id": 1,
        "name": "completed"
    },
    "amount": {
        "total": "20.0000",
        "charged": "20.0000",
        "canceled": "0.0000",
        "remaining": "0.0000"
    },
    "currency": "EUR",
    "orderId": "",
    "invoiceId": "",
    "resources": {
        "customerId": "",
        "paymentId": "s-pay-131937",
        "basketId": "",
        "metadataId": "",
        "payPageId": "",
        "traceId": "70ddf3152a798c554d9751a6d77812ae",
        "typeId": "s-ppl-grpucjmy5zrk"
    },
    "transactions": [
        {
            "date": "2021-05-10 00:51:03",
            "type": "charge",
            "status": "success",
            "url": "https://api.unzer.com/v1/payments/s-pay-131937/charges/s-chg-1",
            "amount": "20.0000"
        }
    ]
}

Step 4: Display the payment result

client side

Use the information from the Check status of the payment step to display the payment result to your customer.
This can be the success or error page of your shop. If something went wrong, you can use the client message from the API response and show it to the customer.

Manage payment

server side

For more details on managing PayPal payments, such as refunding them, see Manage PayPal payments

Notifications

We recommend subscribing to the payment event to receive notifications about any changes to the payment resource. As soon as the event is triggered you should fetch the payment and update the order status in your shop according to its status.

  {
    "event":"payment.pending",
    "publicKey":"s-pub-xxxxxxxxxx",
    "retrieveUrl":"https://api.unzer.com/v1/payments/s-pay-774",
    "paymentId":"s-pay-774"
  }

For more details on implementing webhooks to receive notifications, see Notifications page.

Error handling

All requests to the API can result in an error that should be handled. Refer to the Error handling guide to learn more about Unzer API (and other) errors and handling them.

Test & go live

You should always test your integration before going live. First perform test transactions using test data. Next, check against Integration checklist and Go-live checklist to make sure the integration is complete and you’re ready to go live.

See also

• Manage API resources:
  • Manage API resources (direct API calls)
  • Manage API resources (PHP SDK)
  • Manage API resources (Java SDK)
• Unzer API basics