1# Universal Attributes 2 3 4## Common Attributes 5 6Common attributes are used to set component identities and appearance. 7 8| Name| Type| Mandatory| Description| 9| -------- | -------- | -------- | -------- | 10| id | string | No| Unique ID of the component.| 11| style | string | No| Style declaration of the component.| 12| class | string | No| Style class of the component, which is used to refer to a style table.| 13| ref | string | No| Reference information of child elements, which is registered with the parent component on **$refs**.| 14 15 16## Rendering Attributes 17 18Rendering attributes are used to set whether a component is rendered. 19 20| Name| Type| Description| 21| -------- | -------- | -------- | 22| for | Array | Expands the current element based on the configured data list.| 23| if | boolean | Whether the element is added or removed.| 24| show | boolean | Whether the element is displayed or hidden.| 25 26> **NOTE** 27> 28> Do not set styles in attribute fields. 29