# Retrieve transactions

Retrieve a single transaction or list multiple transactions with the Tap to Pay on iPhone SDK using the reporting listener.

**Prerequisites:** [Authentication](/api/authentication) · [Run a sale](/guides/payments/tap-to-pay-on-iphone/run-a-sale)

You can use the SDK to view your transactions, which include sales and refunds.

The steps that you follow depend on whether you want to [retrieve a single transaction](#retrieve-a-single-transaction) or [list your transactions](#list-your-transactions).

We return all results to the `CoreAPIReportingListener`.

<a id="retrieve-a-single-transaction"></a>
## Retrieve a single transaction

Before you retrieve a single transaction, you need to have the `uniqueRef` of the transaction. If you don't have the `uniqueRef`, go to [List your transactions](#list-your-transactions).

To retrieve a transaction, register the reporting listener, and then call `getTransaction:` with the `uniqueRef`.

<a id="step-1-register-the-reporting-listener"></a>
### Step 1. Register the reporting listener

- Register `CoreAPIReportingListener` when your view appears, and unregister it when the view disappears.

**`Swift`**

```swift
// viewWillAppear:
terminal.register(self as CoreAPIReportingListener)

// viewWillDisappear:
terminal.unRegister(self as CoreAPIReportingListener)
```

**`Objective-C`**

```objectivec
// viewWillAppear:
[[WTPSTerminal singleton] registerCoreAPIReportingListener:self];

// viewWillDisappear:
[[WTPSTerminal singleton] unRegisterCoreAPIReportingListener:self];
```

<a id="step-2-retrieve-the-transaction"></a>
### Step 2. Retrieve the transaction

- Call `getTransaction:` with a `uniqueRef` to get the full details of a transaction.

**`Swift`**

```swift
terminal.getTransaction(uniqueRef)
```

**`Objective-C`**

```objectivec
[[WTPSTerminal singleton] getTransaction:uniqueRef];
```

The SDK returns the transaction details to `onTransactionRetrieved:` as a `CoreResponse`.

<a id="list-your-transactions"></a>
## List your transactions

If you want to view a list of your transactions, you can use the SDK to return multiple transactions. To handle large numbers of results, the SDK uses pagination to split the request into multiple pages. You can then navigate the pages to view all the transactions that the SDK returned.

To list your transactions, register your reporting listener, and then call `getTransactions:` with optional filters. You can then navigate through the results.

<a id="step-1-register-the-reporting-listener-1"></a>
### Step 1. Register the reporting listener

- Register `CoreAPIReportingListener` when your view appears, and unregister it when the view disappears.

**`Swift`**

```swift
// viewWillAppear:
terminal.register(self as CoreAPIReportingListener)

// viewWillDisappear:
terminal.unRegister(self as CoreAPIReportingListener)
```

**`Objective-C`**

```objectivec
// viewWillAppear:
[[WTPSTerminal singleton] registerCoreAPIReportingListener:self];

// viewWillDisappear:
[[WTPSTerminal singleton] unRegisterCoreAPIReportingListener:self];
```

<a id="step-2-list-transactions"></a>
### Step 2. List transactions

1. Create a `CoreTransactionFilter`.
2. (Optional) To filter your results by date, send a value for `startDate` and for `endDate`.
3. (Optional) To filter your results by transaction state, send a value for `state`.
4. (Optional) To adjust the number of results returned in each page, send a value for `resultsPerPage`.
5. Call `getTransactions:`.

The following example lists transactions with filters for transaction state and dates. The example also specifies that the SDK returns 25 results in each page:

**`Swift`**

```swift
let filter = CoreTransactionFilter()
filter.state = OPEN // OPEN, CLOSED, or ALL

let calendar = NSCalendar(calendarIdentifier: .gregorian)!

var from = calendar.components([.day, .month, .year], from: fromDatePicker.date)
from.hour = 0; from.minute = 0; from.second = 0
filter.startDate = calendar.date(from: from)

var to = calendar.components([.day, .month, .year], from: toDatePicker.date)
to.hour = 23; to.minute = 59; to.second = 59
filter.endDate = calendar.date(from: to)

filter.resultsPerPage = 25

terminal.getTransactions(filter)
```

**`Objective-C`**

```objectivec
CoreTransactionFilter *filter = [[CoreTransactionFilter alloc] init];
filter.state = OPEN; // OPEN, CLOSED, or ALL

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];

NSDateComponents *from = [calendar components:(NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear)
                                     fromDate:self.fromDate.date];
from.hour = 0; from.minute = 0; from.second = 0;
filter.startDate = [calendar dateFromComponents:from];

NSDateComponents *to = [calendar components:(NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear)
                                   fromDate:self.toDate.date];
to.hour = 23; to.minute = 59; to.second = 59;
filter.endDate = [calendar dateFromComponents:to];

filter.resultsPerPage = @25;

[[WTPSTerminal singleton] getTransactions:filter];
```

The SDK returns the results to `onTransactionListResponse:` in a `CoreTransactions` object. The `CoreTransactions` object has a `transactionSummary` array of `CoreTransactionSummary` items, each containing information about a transaction.

**Note:** `CoreTransactionSummary` doesn't include receipt information. If you want to view `merchantReceipt` or `cardholderReceipt`, [retrieve the single transaction](#retrieve-a-single-transaction) instead.

The following code prints each result to the console:

**`Swift`**

```swift
func onTransactionListResponse(_ transactions: CoreTransactions!) {
    guard let summaries = transactions.transactionSummary, summaries.count > 0 else {
        return // No more results
    }
    for case let summary as CoreTransactionSummary in summaries {
        print("\(summary.uniqueRef ?? "") - \(summary.transactionType ?? "") \(summary.amount ?? 0)")
    }
}
```

**`Objective-C`**

```objectivec
- (void)onTransactionListResponse:(CoreTransactions *)transactions {
    if (transactions.transactionSummary.count == 0) {
        return; // No more results
    }
    for (CoreTransactionSummary *summary in transactions.transactionSummary) {
        NSLog(@"%@ - %@ %@", summary.uniqueRef, summary.transactionType, summary.amount);
    }
}
```

<a id="step-3-navigate-through-the-results"></a>
### Step 3. Navigate through the results

When the SDK returns the `CoreTransactions` object, it includes a `next` field.

To get the next page, set `filter.next` to the value that you received in the `next` field, and then call `getTransactions:` again. If there are no more results, the SDK doesn't return a `next` value.

The following code navigates to the next page of results:

**`Swift`**

```swift
// In onTransactionListResponse: store the next cursor
nextPage = transactions.next

// When the last visible row is displayed:
if let nextPageRef = nextPage, !nextPageRef.isEmpty {
    filter.next = nextPageRef
    terminal.getTransactions(filter)
}
```

**`Objective-C`**

```objectivec
// In onTransactionListResponse: store the next cursor
self.nextPage = transactions.next;

// When the last visible row is displayed:
if (self.nextPage.length > 0) {
    filter.next = self.nextPage;
    [[WTPSTerminal singleton] getTransactions:filter];
}
```