# xendit-components-web

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With Xendit Components, you can build a checkout experience tightly integrated into your site, powered by the Xendit Sessions API.

This SDK provides UI components for payment method selection, user input (e.g. credit cards), and user actions (e.g. 3DS), all of which can be customized to match your site's look & feel.

View a live demo [here](https://demo-store.xendit.co/) by choosing "Xendit Components". View the demo source code [here](https://github.com/xendit/demo-store/tree/main/src/integrations).

## Installation

Install using npm:

```sh
npm install xendit-components-web --save
```

Or load it directly from our CDN:

```html
<script src="https://assets.xendit.co/components/v0.0.25/index.umd.js"></script>
```

Our npm package includes TypeScript types. You also download the [.d.ts file](https://assets.xendit.co/components/v0.0.25/index.d.ts) directly.

## Sessions

The Xendit Session API is an abstraction over the Xendit Payments API, representing one transaction (or tokenization). Using one session, a user can make any number
of attempts to pay, one of which can be successful. A successful payment completes the session.

Sessions also abstract away any differences between channels, allowing you to write once, and accept payments from any channel Xendit supports.

Two types of sessions are available:

- `PAY` sessions collect a payment and optionally save a payment token for later use
- `SAVE` sessions save a payment token

## Quick Start

First, initialize the SDK either with either:

- Use `XenditComponentsTest` to use mock payment methods for development and testing.
- Use `XenditComponents` to connect to the Xendit backend (including Xendit's test mode). This requires a `componentsSdkKey` option, which you can get by calling the Create Session endpoint. Create a session from your server, passing the `components_sdk_key` property back to your frontend.

```typescript
// For frontend development, use XenditComponentsTest, this provides built-in mock payment methods
const components: XenditComponents = new XenditComponentsTest({});
// For production or e2e testing, use XenditComponents, passing in the components_sdk_key from the Session object
const components: XenditComponents = new XenditComponents({ componentsSdkKey });

// Create a channel picker component
const channelPicker: HTMLElement = components.createChannelPickerComponent();

// Insert the channel picker into your document
myCheckoutPage.replaceChildren(channelPicker);

// Call submit() when the user clicks your submit button
mySubmitButton.addEventListener("click", () => {
  components.submit();
});

// Listen to the status of the session
components.addEventListener("session-complete", () => {
  alert("Payment Success");
});
components.addEventListener("session-expired-or-canceled", () => {
  alert("Payment cancelled or expired");
});
```

## Components API

### `XenditComponents` and `XenditComponentsTest`

Constructor functions.

Both have the same API. `XenditComponents` will connect to Xendit servers, while `XenditComponentsTest` provides mock payment channels.

### `createChannelPickerComponent`

```typescript
const htmlElement = components.createChannelPickerComponent();
myContainer.replaceChildren(htmlElement);
```

Creates a UI for the user to select a payment channel and fill any required information.

This returns a `HTMLElement`, which you need to insert into your document.

This method uses caching, it will always return the same channel picker element.
Changing the current channel will update the channel picker UI, even if it's unmounted.
If you don't want this, use `destroyComponent.`

### `getActiveChannels`

```typescript
const channels = components.getActiveChannels();
```

Returns the list of channels available in this session.

### `getActiveChannelGroups`

```typescript
const groups = components.getActiveChannelGroups();
```

Returns a list of channel groups. This can be used to categorize channels by type, if you want to build
your own channel selection UI. Each channel has a `uiGroup` property which matches one group's `id` property.

<!--
### `getActiveDigitalWallets`

```typescript
const digitalWallets = components.getActiveDigitalWallets();
```

Returns a list of digital wallets available in this session.
-->

### `createChannelComponent`

```typescript
const channel = components.getActiveChannels({ filter: "CARDS" })[0];
if (channel) {
  const htmlElement = components.createChannelComponent(channel);
  myContainer.replaceChildren(htmlElement);
}
```

Selects a payment channel and creates a UI for the user to fill any required information. You
need to pass in the channel you want to use, as returned from getActiveChannels.

This returns a `HTMLElement`, which you need to insert into your document.

This method uses caching, it will always return the same element for the same channel, to preserve the
values the user enters into any form fields. If you don't want that, use `destroyComponent`.

<!--
### `createDigitalWalletComponent`

```typescript
const htmlElement = components.createDigitalWalletComponent("GOOGLE_PAY");
```

Creates a digital wallet CTA button for the specified digital wallet.

After a user clicks the button and completes the digital wallet flow, a submission will automatically begin. This is equivalent to setting the channel used (using `setCurrentChannel()`), and then calling `submit()`. The same events will be fired as a normal submission.

This returns a `HTMLElement`, which you need to insert into your document.
-->

### `createActionContainerComponent`

```typescript
components.addEventListener("action-begin", () => {
  const htmlElement = components.createActionContainerComponent({
    qrCode: {
      qrCodeOnly: true,
    },
  });
  myActionContainer.replaceChildren(htmlElement);
});
```

Creates a container into which any additional actions (e.g. 3DS, QR Codes) will be rendered.

This is optional, if you don't create one, the SDK will create a modal with an action container for you.
You cannot create an action container during an action (i.e. after the `action-begin` event).

This returns a `HTMLElement`, which you need to insert into your document.

This method does not use caching.

### `submit`

```typescript
function onSubmitButtonClick() {
  components.submit();
}
```

Begins submission for the active payment channel.

Call this from the click event of your submit button.

Submission is only available when the session is active, a channel is made current by creating a channel component, any required information is collected, and
another submission is not in progress. Use the `submission-ready` and `submission-not-ready` events to know when submission is available.

This calls the [create payment request](https://docs.xendit.co/apidocs/create-payment-request)
or [create payment token](https://docs.xendit.co/apidocs/create-payment-token) endpoint depending on the session type. You
may listen to the corresponding webhooks on your server.

### `simulatePayment`

```typescript
components.simulatePayment();
```

Calls the [simulate payment](https://docs.xendit.co/apidocs/simulate-payment-test-mode) endpoint.

This is only available in test mode sessions. It also requires the payment channel to be a QR, OTC, or VA channel, and it requires an action
to be in-progress.

### `abortSubmission`

```typescript
components.abortSubmission();
```

Cancels the current submission, if any.

### `destroyComponent`

```typescript
components.destroyComponent(htmlElement);
```

Destroys a component, deleting any cached data and removing the element from the document. Manual cleanup is not normally required,
but is made available if you want it.

### `showValidationErrors`

```typescript
components.showValidationErrors();
```

Reveals hidden validation errors in the current channel's form, if any.

Validation errors are normally hidden until the user changes and unfocusses the input.

### `getCurrentChannel`

```typescript
const channel: XenditChannel = components.getCurrentChannel();
```

Returns the current channel.

The current channel is the one you or the channel picker component selected by calling `createChannelComponent` or `setCurrentChannel`.

The current channel:

- Will be used for submission when you call `submit()`
- Is interactive (other channel components are disabled)

### `setCurrentChannel`

```typescript
const channel = components.getActiveChannels({ filter: "CARDS" })[0];
if (channel) {
  components.setCurrentChannel(channel);
}
```

Makes the provided channel the current channel.

### `pollImmediately`

```typescript
components.pollImmediately();
```

Immediately poll for the status of a submission. Only applicable while a submission is ongoing. Useful for handling payment affirmation (e.g. I have made the payment) by the user.

## Events

### `init`

Notifies you when the session information is loaded. Most SDK functions require the session to be loaded and can only be called after this event.

`createChannelPickerComponent` is available before the init event.

### `session-complete` and `session-expired-or-canceled`

Notifies you when the session is in a terminal state.

`session-complete` means the session was successful, `session-expired-or-canceled` means the session was cancelled or expired.

### `session-pending` and `session-not-pending`

Notifies you when the session is in the pending state. The pending state means a payment request or token will take some time to complete due to a manual approval flow. This affects FPX business payments. No other payment attempts can be made while in the pending state.

You might want to show a pending state UI when in the pending state.

### `submission-ready` and `submission-not-ready`

Notifies you when the user is ready to submit the payment, meaning a channel is selected and all required information is collected.

`submit` will only work in the ready state, or it will throw. Calling it when there are form validation errors will also reveal those errors
to the user.

You might want to disable your submit button when not in the ready state.

### `submission-begin` and `submission-end`

Notifies you when a submission is in progress.

You might want to show a pending state UI when in the submission state, and allowing the action UI to show on top.

### `submission-resume`

Notifies you when the SDK is resuming a previous attempt after the user returns to your `return_url` (see [Resuming after a redirect](#resuming-after-a-redirect)). This event is only fired for sessions that are still active. It behaves the same as `submission-begin`, and the events that follow will also be the same.

If the session is already complete, expired, or cancelled, the the resume event is not fired.

### `action-begin` and `action-end`

Notifies you when an action is in progress.

Optionally, you can create an action container in the action-begin event. A default action container modal will be created if you don't.

## Resuming after a redirect

Some channels redirect the user away from your page to pay (e.g. DANA, OVO). When they return to the `components_configuration.return_url` you set on the session, re-initialize the SDK in the same way, with the same key, but with `resume: true` to continue the payment flow:

```typescript
const components = new XenditComponents({
  componentsSdkKey, // the same session key as before
  resume: true,
});
```

We append query string parameters to your `return_url`, which must be preserved until you initialize the SDK.

After initialization, if the session is still active, a `submission-resume` event fires. The SDK is then in the submitting state, as if you had called `submit()`, and the usual flow follows from there.

A `fatal-error` is fired if the query string parameters are not preserved, or if they don't match the key you use to initialize.

Only set `resume: true` when you intend to resume a payment flow, i.e. on your `return_url`.

## Appearance

### CSS

The Xendit Components SDK is designed to be customized with CSS. You can override any styles with your own CSS. The SDK's base is inserted above other stylesheets at the time of loading to allow it to be easily overridden.

Refer to [styles.css](https://github.com/xendit/xendit-components-web/blob/main/sdk/src/styles.css) for all the overidable selectors.

### CSS Variables

Some CSS variables are provided to allow for easy customization. These are defined on `:root` and can be overridden by your own CSS.

The following variables are available:
| Variable | Description |
| :- | :- |
| --xendit-font-family | Font applied to all xendit components |
| --xendit-color-primary | Accent color |
| --xendit-color-text | Base text color |
| --xendit-color-text-secondary | Lighter text color |
| --xendit-color-text-placeholder | Placeholder color |
| --xendit-color-disabled | Background color of disabled elements |
| --xendit-color-danger | Border color of elements with validation errors and text color of validation errors |
| --xendit-color-border | Border color used on accordions, input fields, and logos |
| --xendit-color-background | Background color of input fields |
| --xendit-focus-shadow | Box-shadow applied to elements with focus |
| --xendit-animation-duration | Duration of animations (affects the channel picker accordion) |
| --xendit-animation-ease | Ease function of animations |
| --xendit-radius-1 | Border radius applied to some components |
| --xendit-z-index-focus | Z-index applied to focused fields |
| --xendit-qr-foreground-color | The color used for QR codes (the black pixels). |
| --xendit-qr-background-color | The color used as the background of QR codes (the white pixels). |

Additionally, the following variables are set at component scope, where applicable:
| Variable | Description |
| :- | :- |
| --xendit-channel-brand-color | A brand color. Varies depending on the channel or action component where it's used. Will always be a dark color appropriate for use as a background behind white text. |

### CSS In Iframe Fields

Some form fields (credit card inputs) are implemented inside iframes to protect the user's information.

You can't override the CSS inside the iframe fields. Instead, you can pass some limited styles to the constructor
which we'll pass along to the iframes.

```typescript
const sdk = new XenditComponents({
  iframeFieldAppearance: {
    inputStyles: {
      // apply styles to inputs within iframe fields
      color: "#000",
    },
    placeholderStyles: {
      // apply styles to input placeholders in iframe fields
      color: "#ccc",
    },
  },
});
```

### Fonts In Iframe Fields

Iframes can't inherit fonts you define on your page, so we allow you to load the font separately inside the iframe, by passing the font source to the constructor.

```typescript
const sdk = new XenditComponents({
  iframeFieldAppearance: {
    inputStyles: {
      // fontFamily: "serif", // this is ignored if a fontFace is provided
    }
    fontFace: {
      // insert a @font-face rule inside iframe fields
      source: "url(https://example.com/my-font-file) format(woff2)",
      descriptors: { display: "swap" },
    },
  },
});
```

<!--
## Digital Wallet Support

Any available Digital Wallet integration is automatically added at the top of the channel picker component. You may also create a Digital Wallet button manually by calling `createDigitalWalletComponent("GOOGLE_PAY")`.

When the user pays using the digital wallet, the submission flow will automatically begin, the same as if you had called `submit()`.

Google Pay is currently the only supported digital wallet.

### Google Pay™

Google Pay is available to Sessions that meet the following requirements:

- Your Session country is a country where Google Pay is supported.
- You have at least one Google Pay compatible payment method available in your session. (e.g. cards)
- You've provided your Google MerchantID to Xendit on the Xendit Dashboard. (If you don't have a Google MerchantID, complete registration with the [Google Pay & Wallet Console](https://pay.google.com/business/console/?utm_source=devsite&utm_medium=devsite&utm_campaign=devsite) to provision one)
- The Google Pay SDK is loaded using `<script async src="https://pay.google.com/gp/p/js/pay.js"></script>`. (You need to include the SDK yourself, we don't bundle it. There's no need to wait for it to finish loading, if it's still loading when you create the component, it'll have `display:none` until it finishes loading)
- The user is using a compatible browser. (The component will have `display:none` if the user is using an incompatible browser)

We configure Google Pay for you, providing your MerchantID, merchant name, and the allowed payment methods, including allowed card networks and authentication methods.

You can customize the appearance of the button using the options parameter of `createDigitalWalletComponent`, it accepts the same options as the [Google Pay API](https://developers.google.com/pay/api/web/reference/request-objects#ButtonOptions).

To use Google Pay, you must adhere to the Google Pay and Wallet API's [Acceptable Use Policy](https://payments.developers.google.com/terms/aup) and accept the terms defined in the [Google Pay API Terms of Service](https://payments.developers.google.com/terms/sellertos). Additionally, please ensure you follow the [Google Pay brand guidelines](https://developers.google.com/pay/api/web/guides/brand-guidelines).
-->

## Troubleshooting

### Usage with React Strict Mode

Since React 18, Strict Mode will perform mount/unmount checks during development. This means React intentionally unmounts and remounts every component on its initial mount.

If you instantiate XenditComponents and add a listener for the `init` event in a side effect, this can cause a race condition where the event fires for the last instance before the first instance finishes mounting. Hence, you should remember to remove the `init` event listener in the effect cleanup function when Strict Mode is on.

```typescript
useEffect(() => {
  // ...
  const handleInit = () => {
    // ...
  };
  components.addEventListener("init", handleInit);
  return () => {
    components.removeEventListener("init", handleInit);
  };
}, []);
```