---
title: SecTransformMetaAttributeType.required
framework: security
role: symbol
role_heading: Case
path: security/sectransformmetaattributetype/required
---

# SecTransformMetaAttributeType.required

Indicates whether the attribute value is optional.

## Declaration

```swift
case required
```

## Discussion

Discussion Specifies if an attribute must have a non NULL value set or have an incoming connection before the transform starts to execute. This metadata has a default value of true for the input attribute, but false for all other attributes.