# Javascript: TXTextControl.setAllowUndo Method

> Sets a value indicating whether the undo buffer is active or not.

- **Product:** DS Server
- **Section:** Reference
- **Kind:** Method
- **Introduced:** 28.0
- **Path:** DS Server > Reference > JavaScript API > Javascript: TXTextControl.setAllowUndo Method
- **338 words**
- **Web URL:** https://docs.textcontrol.com/ds-server/reference/javascript/txtextcontrol/setallowundo-method/
- **LLMs URL:** https://docs.textcontrol.com/ds-server/reference/javascript/txtextcontrol/setallowundo-method/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/ds-server/reference/javascript/txtextcontrol/setallowundo-method/llms-full.txt

---

### Description

Sets a value indicating whether the undo buffer is active or not.

### Syntax

```javascript
<void> TXTextControl.setAllowUndo(<boolean> allowUndo, [<EmptyRequestCallback> callback], [<ErrorCallback> errorCallback])
```

### Parameters

| Parameter | Description |
|---|---|
| allowUndo | Specifies whether the undo buffer is active or not. |
| callback | Optional. Is called when the operation completed. |
| errorCallback | Optional. Is called when the operation failed with an error. |

### Examples

The following example demonstrates `TXTextControl.setAllowUndo` in a practical document-editing workflow. It sets a value indicating whether the undo buffer is active or not.

```javascript
function onTxError(error) {
    console.error("TX Text Control error:", error.msg);
    error.handled = true;
}

TXTextControl.setAllowUndo(
    true,
    function() {
        console.log("set allow undo completed.");
    },
    onTxError
);
```

---

## Nearby

- **Previous:** [Javascript: TXTextControl.setAllowDrop Method](https://docs.textcontrol.com/ds-server/reference/javascript/txtextcontrol/setallowdrop-method/llms-full.txt)
- **Next:** [Javascript: TXTextControl.setBackColor Method](https://docs.textcontrol.com/ds-server/reference/javascript/txtextcontrol/setbackcolor-method/llms-full.txt)