paypal-js
Loading wrapper and TypeScript types for the PayPal JS SDK
Why use paypal-js?
The default JS SDK code snippet blocks page rendering:
<script src="https://www.paypal.com/sdk/js?client-id=test"></script>
<script>
paypal.Buttons().render("body");
</script>
The above snippet can be difficult to implement in a non-blocking way, especially in single page web apps. This is where the paypal-js library comes in. It provides the following benefits over the above snippet:
- Async script loading to ensure page rendering isn't blocked.
- A Promise API to know when script loading is complete.
- A convenient way to reload the script when query parameters or data attributes change.
Installation
To get started, install paypal-js with npm.
npm install @paypal/paypal-js
Usage
Import the loadScript
function for asynchronously loading the Paypal JS SDK.
loadScript(options)
- accepts an object for passing query parameters and attributes to the JS SDK.
- returns a Promise that resolves with
window.paypal
after the JS SDK is finished loading.
Async/Await
import { loadScript } from "@paypal/paypal-js";
let paypal;
try {
paypal = await loadScript({ clientId: "test" });
} catch (error) {
console.error("failed to load the PayPal JS SDK script", error);
}
if (paypal) {
try {
await paypal.Buttons().render("#your-container-element");
} catch (error) {
console.error("failed to render the PayPal Buttons", error);
}
}
Promises
import { loadScript } from "@paypal/paypal-js";
loadScript({ clientId: "test" })
.then((paypal) => {
paypal
.Buttons()
.render("#your-container-element")
.catch((error) => {
console.error("failed to render the PayPal Buttons", error);
});
})
.catch((error) => {
console.error("failed to load the PayPal JS SDK script", error);
});
Passing Arguments
The loadScript
function accepts an object for configuring the JS SDK. It's used for setting query parameters and script attributes. It accepts parameters in camelCase or kebab-case.
Query Parameters
The following example adds client-id
and currency
as query string parameters:
loadScript({ clientId: "YOUR_CLIENT_ID", currency: "EUR" });
Which will load the following <script>
asynchronously:
<script src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID¤cy=EUR"></script>
By default, the JS SDK only loads the buttons component. The components
query string parameter can be used to load multiple components:
loadScript({
clientId: "YOUR_CLIENT_ID",
components: "buttons,marks,messages",
});
Which will load the following <script>
asynchronously:
<script src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID&components=buttons,marks,messages"></script>
View the full list of supported query parameters.
Data Attributes
All options prefixed with data
are considered attributes. The following example adds data-page-type
as an attribute:
loadScript({
clientId: "YOUR_CLIENT_ID",
dataPageType: "checkout",
});
Which will load the following <script>
asynchronously:
<script
data-page-type="checkout"
src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID"
></script>
View the full list of supported script parameters.
Merchant Id Array
The merchantId
option accepts an array to simplify the implementation for Multi-Seller Payments. With this approach the caller doesn't have to worry about managing the two different merchant id values (data-merchant-id
and merchant-id
).
Here's an example with multiple merchantId
values:
loadScript({
clientId: "YOUR_CLIENT_ID",
merchantId: ["123", "456", "789"],
});
Which will load the following <script>
and use merchant-id=*
to properly configure the edge cache:
<script
data-merchant-id="123,456,789"
src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID&merchant-id=*"
></script>
Here's an example with one merchant-id
value:
loadScript({
clientId: "YOUR_CLIENT_ID",
merchantId: ["123"],
});
When there's only one, the merchant-id is passed in using the query string.
<script src="https://www.paypal.com/sdk/js?client-id=YOUR_CLIENT_ID&merchant-id=123"></script>
sdkBaseUrl
For local development, the sdkBaseUrl
option can be used to set the base url of the JS SDK:
loadScript({
clientId: "YOUR_CLIENT_ID",
sdkBaseUrl: "http://localhost.paypal.com:8000/sdk/js",
});
Legacy Browser Support
This library relies on JavaScript Promises. To support legacy browsers like IE 11, you must provide your own Promise polyfill. With a Promise polyfill this library will support the same browsers as the JS SDK.
The loadScript()
function takes in a second parameter for providing a Promise ponyfill. It defaults to the global Promise
object if it exists. There are two options for polyfilling the Promise object:
- Use a global polyfill strategy that monkey patches the
window.Promise
API implementation. - Use a ponyfill strategy that passes a Promise library into
loadScript()
without affecting other code:
import { loadScript } from "@paypal/paypal-js";
import PromisePonyfill from "promise-polyfill";
loadScript(options, PromisePonyfill).then((paypalObject) => {});
We also provide a legacy build that includes the promise-polyfill library. You can reference it from the CDN here:
<script src="https://unpkg.com/@paypal/paypal-js@6.0.1/dist/iife/paypal-js.legacy.min.js"></script>
Using a CDN
The paypal-js script is also available on the unpkg CDN. The iife/paypal-js.js build assigns the loadScript
function to the window object as window.paypalLoadScript
. Here's an example:
<!doctype html>
<html lang="en">
<head>
<script src="https://unpkg.com/@paypal/paypal-js@6.0.1/dist/iife/paypal-js.min.js"></script>
</head>
<body>
<div id="paypal-buttons"></div>
<script>
window.paypalLoadScript({ clientId: "test" }).then((paypal) => {
paypal.Buttons().render("#paypal-buttons");
});
</script>
</body>
</html>
loadCustomScript(options)
The loadCustomScript
function is a generic script loader function that works with any url.
- accepts an object for defining the script url and attributes.
- returns a promise to indicate if the script was successfully loaded.
Async/Await
import { loadCustomScript } from "@paypal/paypal-js";
try {
await loadCustomScript({
url: "https://www.example.com/index.js",
attributes: {
id: "custom-id-value",
"data-foo": "custom-data-attribute",
},
});
console.log("successfully loaded the custom script");
} catch (error) {
console.error("failed to load the custom script", error);
}
Promises
import { loadCustomScript } from "@paypal/paypal-js";
loadCustomScript({
url: "https://www.example.com/index.js",
attributes: { id: "custom-id-value", "data-foo": "custom-data-attribute" },
})
.then(() => {
console.log("successfully loaded the custom script");
})
.catch((err) => {
console.error("failed to load the custom script", err);
});
TypeScript Support
This package includes TypeScript type definitions for the PayPal JS SDK. This includes types for the window.paypal
namespace. We support projects using TypeScript versions >= 3.8.
Releasing
Run npm run release
to publish a new release. The version number is determined by the git commits which follow conventional commits spec.