---
title: "setComponent(_:for:)"
framework: modelio
role: symbol
role_heading: Instance Method
path: "modelio/mdlobject/setcomponent(_:for:)"
---

# setComponent(_:for:)

Associates a component with the object for the specified protocol.

## Declaration

```swift
func setComponent(_ component: any MDLComponent, for protocol: Protocol)
```

## Parameters

- `component`: The component to associate with the object. The component class must adopt the protocol specified in the protocol parameter.
- `protocol`: The protocol whose functionality the component provides.

## Discussion

Discussion Components are the basis for customizable file format and object graph support in Model I/O. By default, the MDLObject uses the MDLObjectContainerComponent and MDLTransformComponent protocols to model object hierarchies and spatial transforms: When you load an object graph from a MDLAsset instance, Model I/O creates container and transforms components to represent the object hierarchy and spatial relationships described in the asset file. However, you can also create custom components. For example, a custom component protocol could add support for an asset format that encodes gameplay-related information such as scripting triggers, or a custom class for the MDLObjectContainerComponent could implement other ways to store or traverse object hierarchies.

## See Also

### Customizing Objects with Components

- [componentConforming(to:)](modelio/mdlobject/componentconforming(to:).md)