# Universal Attributes


## Common Attributes

Common attributes are used to set component identities and appearance.

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| id | string | No| Unique ID of the component.|
| style | string | No| Style declaration of the component.|
| class | string | No| Style class of the component, which is used to refer to a style table.|
| ref | string | No| Reference information of child elements, which is registered with the parent component on **$refs**.|


## Rendering Attributes

Rendering attributes are used to set whether a component is rendered.

| Name| Type| Description|
| -------- | -------- | -------- |
| for | Array | Expands the current element based on the configured data list.|
| if | boolean | Whether the element is added or removed.|
| show | boolean | Whether the element is displayed or hidden.|

> **NOTE**
>
> Do not set styles in attribute fields.