# In-App Purchase (macOS)

## Preparing

### Paid Applications Agreement
If you haven't already, you’ll need to sign the Paid Applications Agreement and set up your banking and tax information in iTunes Connect.

[iTunes Connect Developer Help: Agreements, tax, and banking overview](https://help.apple.com/itunes-connect/developer/#/devb6df5ee51)

### Create Your In-App Purchases
Then, you'll need to configure your in-app purchases in iTunes Connect, and include details such as name, pricing, and description that highlights the features and functionality of your in-app purchase.

[iTunes Connect Developer Help: Create an in-app purchase](https://help.apple.com/itunes-connect/developer/#/devae49fb316)

### Change the CFBundleIdentifier

To test In-App Purchase in development with Electron you'll have to change the `CFBundleIdentifier` in `node_modules/electron/dist/Electron.app/Contents/Info.plist`. You have to replace `com.github.electron` by the bundle identifier of the application you created with iTunes Connect.

```xml
<key>CFBundleIdentifier</key>
<string>com.example.app</string>
```

## Code example

Here is an example that shows how to use In-App Purchases in Electron. You'll have to replace the product ids by the identifiers of the products created with iTunes Connect (the identifier of `com.example.app.product1` is `product1`). Note that you have to listen to the `transactions-updated` event as soon as possible in your app.

```javascript
const { inAppPurchase } = require('electron').remote
const PRODUCT_IDS = ['id1', 'id2']

// Listen for transactions as soon as possible.
inAppPurchase.on('transactions-updated', (event, transactions) => {
  if (!Array.isArray(transactions)) {
    return
  }

  // Check each transaction.
  transactions.forEach(function (transaction) {
    let payment = transaction.payment

    switch (transaction.transactionState) {
      case 'purchasing':
        console.log(`Purchasing ${payment.productIdentifier}...`)
        break
      case 'purchased':

        console.log(`${payment.productIdentifier} purchased.`)

        // Get the receipt url.
        let receiptURL = inAppPurchase.getReceiptURL()

        console.log(`Receipt URL: ${receiptURL}`)

        // Submit the receipt file to the server and check if it is valid.
        // @see https://developer.apple.com/library/content/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateRemotely.html
        // ...
        // If the receipt is valid, the product is purchased
        // ...

        // Finish the transaction.
        inAppPurchase.finishTransactionByDate(transaction.transactionDate)

        break
      case 'failed':

        console.log(`Failed to purchase ${payment.productIdentifier}.`)

        // Finish the transaction.
        inAppPurchase.finishTransactionByDate(transaction.transactionDate)

        break
      case 'restored':

        console.log(`The purchase of ${payment.productIdentifier} has been restored.`)

        break
      case 'deferred':

        console.log(`The purchase of ${payment.productIdentifier} has been deferred.`)

        break
      default:
        break
    }
  })
})

// Check if the user is allowed to make in-app purchase.
if (!inAppPurchase.canMakePayments()) {
  console.log('The user is not allowed to make in-app purchase.')
}

// Retrieve and display the product descriptions.
inAppPurchase.getProducts(PRODUCT_IDS).then(products => {
  // Check the parameters.
  if (!Array.isArray(products) || products.length <= 0) {
    console.log('Unable to retrieve the product informations.')
    return
  }

  // Display the name and price of each product.
  products.forEach(product => {
    console.log(`The price of ${product.localizedTitle} is ${product.formattedPrice}.`)
  })

  // Ask the user which product he/she wants to purchase.
  let selectedProduct = products[0]
  let selectedQuantity = 1

  // Purchase the selected product.
  inAppPurchase.purchaseProduct(selectedProduct.productIdentifier, selectedQuantity).then(isProductValid => {
    if (!isProductValid) {
      console.log('The product is not valid.')
      return
    }

    console.log('The payment has been added to the payment queue.')
  })
})
```
