# igx-transaction

`TransactionService` allows the developers to plug a middleware between given component and its data source. While plugged in `TransactionService` should collect all the transactions performed in the component without send them to the data source. `TransactionService` should be able to update the data source and commit all the transactions when needed.
A walk through of how to get started can be found [here](https://www.infragistics.com/products/ignite-ui-angular/angular/components/transaction)

## Usage

```typescript
@Component({
    providers: [{ provide: IgxGridTransaction, useClass: IgxTransactionImplementation }]
})
```

## Getting Started

### Dependencies

To use the `TransactionService` import the TransactionService:

```typescript
import { IgxGridTransaction, IgxTransactionService } from "igniteui-angular-sovn";
```

and then inject it in the component's constructor:

```typescript
    constructor(@Inject(IgxGridTransaction) private _transactions: TransactionService) { };
```

## API

### TransactionService

| Name                 | Description                                                                                                                         | Parameters              |
| -------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | ----------------------- |
| enabled              | Returns whether transaction is enabled for this service                                                                             | -                       |
| onStateUpdate        | Event fired when transaction state has changed - add transaction, commit all transactions, undo and redo                            | -                       |
| canUndo              | Returns if there are any transactions in the Undo stack                                                                             | -                       |
| canRedo              | Returns if there are any transactions in the Redo stack                                                                             | -                       |
| add                  | Adds provided transaction with recordRef if any                                                                                     | transaction, recordRef? |
| getTransactionLog    | Returns all recorded transactions in chronological order                                                                            | id?                     |
| undo                 | Remove the last transaction if any                                                                                                  | -                       |
| redo                 | Applies the last undone transaction if any                                                                                          | -                       |
| getAggregatedChanges | Returns aggregated changes from all transactions                                                                                    | mergeChanges            |
| getState             | Returns the state of the record with provided id                                                                                    | id, pending             |
| getAggregatedValue   | Returns value of the required id including all uncommitted changes                                                                  | id, mergeChanges        |
| commit               | Applies all transactions over the provided data                                                                                     | data, id?               |
| clear                | Clears all transactions                                                                                                             | id?                     |
| startPending         | Starts pending transactions. All transactions passed after call to startPending will not be added to transaction log                | -                       |
| endPending           | Clears all pending transactions and aggregated pending state. If commit is set to true commits pending states as single transaction | commit                  |

### HierarchicalTransactionService

| Name   | Description                                     | Parameters                          |
| ------ | ----------------------------------------------- | ----------------------------------- |
| commit | Applies all transactions over the provided data | data, primaryKey, childDataKey, id? |