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# SBApplicationDelegate

This informal protocol defines a delegation method for handling Apple event
errors that are sent from a target application to an
<doc://com.apple.documentation/documentation/ScriptingBridge/SBApplication>
object.

```
protocol SBApplicationDelegate
```

## Overview

You must set a delegate for the [`SBApplication`](/documentation/ScriptingBridge/SBApplication) object using the
[`delegate`](/documentation/ScriptingBridge/SBApplication/delegate) method. If you do not set a delegate and have the
delegate handle the error in some way, [`SBApplication`](/documentation/ScriptingBridge/SBApplication) raises an
exception.

## Topics

### Handling Errors

[`-  eventDidFail:withError:`](/documentation/ScriptingBridge/SBApplicationDelegate/eventDidFail(_:withError:))

Sent by an `SBApplication` object when a target application returns an error
Apple event.


---

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