# FormComponent

The **FormComponent** is used to display widgets.

>  **NOTE**
>
> - This component is supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>
> - This component is intended for the widget host. For details about the widget provider, see [JS Service Widget UI Components](../js-service-widget-ui/Readme-EN.md).
> 
> - To use this component, you must have the system signature.

## Required Permissions

ohos.permission.GET_BUNDLE_INFO

ohos.permission.GET_BUNDLE_INFO_PRIVILEGED

ohos.permission.REQUIRE_FORM


## Child Components

Not supported


## APIs

FormComponent(value: {
    id: number;
    name: string;
    bundle: string;
    ability: string;
    module: string;
    dimension?: FormDimension;
    temporary?: boolean
  })

Creates a **FormComponent** instance to display the provided widget.

**Parameters**

| Name   | Type                       | Mandatory| Description                                                               |
| --------- | ------------------------------- | ---- | ----------------------------------------------------------------------- |
| id        | number                          | Yes  | Widget ID. Set this parameter to **0** for a new widget.                                              |
| name      | string                          | Yes  | Widget name.                                                             |
| bundle    | string                          | Yes  | Bundle name of the widget.                                                         |
| ability   | string                          | Yes  | Ability name of the widget.                                                  |
| module    | string                          | Yes  | Module name of the widget.                                                         |
| dimension | [FormDimension](#formdimension) | No  | Dimensions of the widget. The widgets in the 2 x 2, 4 x 4, and 4 x 2 dimensions are supported.<br>Default value: **Dimension_2_2**|
| temporary | boolean                         | No  | Whether the widget is a temporary one.                                                   |

## FormDimension

| Name                      | Description    |
| -------------------------- | -------- |
| Dimension_1_2              | 1 x 2 widget.|
| Dimension_2_2              | 2 x 2 widget.|
| Dimension_2_4              | 2 x 4 widget.|
| Dimension_4_4              | 4 x 4 widget.|
| Dimension_2_1<sup>9+</sup> | 2 x 1 widget.|

## Attributes
| Name       | Type                                                                                             | Mandatory| Description                                                                   |
| ----------- | ----------------------------------------------------------------------------------------------------- | ---- | ----------------------------------------------------------------------- |
| size        | {<br>width?: [Length](ts-types.md#length),<br>height?: [Length](ts-types.md#length)<br>} | Yes  | Size of the widget.                                                         |
| moduleName  | string                                                                                                | Yes  | Module name of the widget.                                                         |
| dimension   | [FormDimension](#formdimension)                                                                       | No  | Dimensions of the widget. The widgets in the 2 x 2, 4 x 4, and 4 x 2 dimensions are supported.<br>Default value: **Dimension_2_2**|
| allowUpdate | boolean                                                                                               | No  | Whether to allow the widget to update.<br>Default value: **true**                                  |
| visibility  | [Visibility](ts-appendix-enums.md#visibility)                                                         | No  | Whether the widget is visible.<br>Default value: **Visible**                               |



## Events

| Name                                                                                                               | Description                                                                                                      |
| ------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| onAcquired(callback: (info: { id: number }) =&gt; void)                          | Triggered when a widget is obtained. This API returns the ID of the obtained widget.                                                                               |
| onError(callback: (info: { errcode: number, msg: string }) =&gt; void) | Triggered when an error occurs during component loading.<br>**errcode**: error code.<br>**msg**: error information.                                        |
| onRouter(callback: (info: any) =&gt; void)                                                      | Triggered when routing occurs for the widget. This API returns information in [routerEvent](../js-service-widget-ui/js-service-widget-syntax-hml.md#event-binding).|
| onUninstall(callback: (info: { id: number }) =&gt; void)                         | Triggered when a widget is uninstalled. This API returns the ID of the uninstalled widget.                                                                               |


## Example

```ts
//card.ets
@Entry
@Component
struct CardExample {
   @State formId:number = 0;
  build() {
    Column() {
      Text('this is a card')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
      FormComponent({
        id:this.formId,
        name:"Form1",
        bundle:"com.example.cardexample",
        ability:"FormAbility",
        module:"entry",
        dimension:FormDimension.Dimension_2_2,
        temporary:false
      })
        .allowUpdate(true)
        .size({width:360,height:360})
        .visibility(Visibility.Visible)
        .onAcquired((form)=>{
          console.log(`form info : ${JSON.stringify(form)}`);
          this.formId = form.id;
        })
        .onError((err)=>{
          console.log(`fail to add form, err: ${JSON.stringify(err)}`);
        })

    }
    .width('100%')
    .height('100%')
  }
}
```

![Form](figures/form.png)