---
title: sourceAttribute
framework: quartzcore
role: symbol
role_heading: Instance Property
path: quartzcore/caconstraint/sourceattribute
---

# sourceAttribute

The constraint attribute of the layer the receiver is calculated relative to

## Declaration

```swift
var sourceAttribute: CAConstraintAttribute { get }
```

## See Also

### Accessing Constraint Values

- [attribute](quartzcore/caconstraint/attribute.md)
- [offset](quartzcore/caconstraint/offset.md)
- [scale](quartzcore/caconstraint/scale.md)
- [sourceName](quartzcore/caconstraint/sourcename.md)