---
title: Form 表单
---
# Form 表单
Form consists of `input`, `radio`, `select`, `checkbox` and so on. With form, you can collect, verify and submit data.
:::tip
The component has been upgraded with a flex layout to replace the old float layout.
:::
## Basic Form
It includes all kinds of input items, such as `input`, `select`, `radio` and `checkbox`.
:::example In each `form` component, you need a `form-item` field to be the container of your input item.
form/basic-form
:::
:::tip
[W3C](https://www.w3.org/MarkUp/html-spec/html-spec_8.html#SEC8.2) regulates that
> When there is only one single-line text input field in a form, the user agent should accept Enter in that field as a request to submit the form.
To prevent this behavior, you can add `@submit.prevent` on ``.
:::
## Inline Form
When the vertical space is limited and the form is relatively simple, you can put it in one line.
:::example Set the `inline` attribute to `true` and the form will be inline.
form/inline-form
:::
## Alignment
Depending on your design, there are several different ways to align your label element.
You can set `label-position` of `el-form-item` separately ^(2.7.7). If the value is empty, the `label-position` of `el-form` is used.
:::example The `label-position` attribute decides how labels align, it can be `top` or `left`. When set to `top`, labels will be placed at the top of the form field.
form/alignment
:::
## Validation
Form component allows you to verify your data, helping you find and correct errors.
:::example Just add the `rules` attribute for `Form` component, pass validation rules, and set `prop` attribute for `FormItem` as a specific key that needs to be validated. See more information at [async-validator](https://github.com/yiminghe/async-validator).
form/validation
:::
## Custom Validation Rules
This example shows how to customize your own validation rules to finish a two-factor password verification.
:::example Here we use `status-icon` to reflect validation result as an icon.
form/custom-validation
:::
:::tip
Custom validate callback function must be called. See more advanced usage at [async-validator](https://github.com/yiminghe/async-validator).
:::
## Add/Delete Form Item
:::example In addition to passing all validation rules at once on the form component, you can also pass the validation rules or delete rules on a single form field dynamically.
form/form-items
:::
## Number Validate
:::example Number Validate need a `.number` modifier added on the input `v-model` binding，it's used to transform the string value to the number which is provided by Vue.
form/number-validate
:::
:::tip
When an `el-form-item` is nested in another `el-form-item`, its label width will be `0`. You can set `label-width` on that `el-form-item` if needed.
:::
## Size Control
All components in a Form inherit their `size` attribute from that Form. Similarly, FormItem also has a `size` attribute.
:::example Still you can fine tune each component's `size` if you don't want that component to inherit its size from From or FormItem.
form/size-control
:::
## Accessibility
When only a single input (or related control such as select or checkbox) is inside of a `el-form-item`, the form item's label will automatically be attached to that input. However, if multiple inputs are inside of the `el-form-item`, the form item will be assigned the [WAI-ARIA](https://www.w3.org/WAI/standards-guidelines/aria/) role of [group](https://www.w3.org/TR/wai-aria/#group) instead. In this case, it is your responsibility to assign assistive labels to the individual inputs.
:::example
form/accessibility
:::
## Form API
### Form Attributes
| Name | Description | Type | Default |
| --------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------- | ------- |
| model | Data of form component. | ^[object]`Record` | — |
| rules | Validation rules of form. | ^[object]`FormRules` | — |
| inline | Whether the form is inline. | ^[boolean] | false |
| label-position | Position of label. If set to `'left'` or `'right'`, `label-width` prop is also required. | ^[enum]`'left' \| 'right' \| 'top'` | right |
| label-width | Width of label, e.g. `'50px'`. All its direct child form items will inherit this value. `auto` is supported. | ^[string] / ^[number] | '' |
| label-suffix | Suffix of the label. | ^[string] | '' |
| hide-required-asterisk | Whether to hide required fields should have a red asterisk (star) beside their labels. | ^[boolean] | false |
| require-asterisk-position | Position of asterisk. | ^[enum]`'left' \| 'right'` | left |
| show-message | Whether to show the error message. | ^[boolean] | true |
| inline-message | Whether to display the error message inline with the form item. | ^[boolean] | false |
| status-icon | Whether to display an icon indicating the validation result. | ^[boolean] | false |
| validate-on-rule-change | Whether to trigger validation when the `rules` prop is changed. | ^[boolean] | true |
| size | Control the size of components in this form. | ^[enum]`'' \| 'large' \| 'default' \| 'small'` | — |
| disabled | Whether to disable all components in this form. Before ^(2.12.0), if set to `true`, it will override the `disabled` prop of the inner component. After ^(2.12.0), the configuration of the internal components takes precedence. | ^[boolean] | false |
| scroll-to-error | When validation fails, scroll to the first error form entry. | ^[boolean] | false |
| scroll-into-view-options ^(2.3.2) | When validation fails, it scrolls to the first error item based on the scrollIntoView option. [scrollIntoView](https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView). | ^[object]`ScrollIntoViewOptions` / ^[boolean] | true |
### Form Events
| Name | Description | Type |
| -------- | --------------------------------------- | ---------------------------------------------------------------------------- |
| validate | triggers after a form item is validated | ^[Function]`(prop: FormItemProp, isValid: boolean, message: string) => void` |
### Form Slots
| Name | Description | Subtags |
| ------- | ------------------------- | -------- |
| default | customize default content | FormItem |
### Form Exposes
| Name | Description | Type |
| -------------------------- | ---------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- |
| validate | Validate the whole form. Receives a callback or returns `Promise`. | ^[Function]`(callback?: FormValidateCallback) => Promise` |
| validateField | Validate specified fields. | ^[Function]`(props?: Arrayable \| undefined, callback?: FormValidateCallback \| undefined) => FormValidationResult` |
| resetFields | Reset specified fields and remove validation result. | ^[Function]`(props?: Arrayable \| undefined) => void` |
| scrollToField | Scroll to the specified fields. | ^[Function]`(prop: FormItemProp) => void` |
| clearValidate | Clear validation messages for all or specified fields. | ^[Function]`(props?: Arrayable \| undefined) => void` |
| fields ^(2.7.3) | Get all fields context. | ^[array]`FormItemContext[]` |
| getField ^(2.10.2) | Get a field context. | ^[Function]`(prop: FormItemProp) => FormItemContext \| undefined` |
| setInitialValues ^(2.13.1) | Set initial values for form fields. When `resetFields` is called, fields will reset to these values. | ^[Function]`(initModel: Record) => void` |
## FormItem API
### FormItem Attributes
| Name | Description | Type | Default |
| ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------- | ------- |
| prop | A key of `model`. It could be a path of the property (e.g `a.b.0` or `['a', 'b', '0']`). In the use of `validate` and `resetFields` method, the attribute is required. | ^[string] / ^[string[]] | — |
| label | Label text. | ^[string] | — |
| label-position ^(2.7.7) | Position of item label. If set to `'left'` or `'right'`, `label-width` prop is also required. Default extend `label-position` of `form`. | ^[enum]`'left' \| 'right' \| 'top'` | '' |
| label-width | Width of label, e.g. `'50px'`. `'auto'` is supported. | ^[string] / ^[number] | — |
| required | Whether the field is required or not, will be determined by validation rules if omitted. | ^[boolean] | — |
| rules | Validation rules of form, see the [following table](#formitemrule), more advanced usage at [async-validator](https://github.com/yiminghe/async-validator). | ^[object]`Arrayable` | — |
| error | Field error message, set its value and the field will validate error and show this message immediately. | ^[string] | — |
| show-message | Whether to show the error message. | ^[boolean] | true |
| inline-message | Inline style validate message. | ^[boolean] | false |
| size | Control the size of components in this form-item. | ^[enum]`'' \| 'large' \| 'default' \| 'small'` | — |
| for | Same as for in native label. | ^[string] | — |
| validate-status | Validation state of formItem. | ^[enum]`'' \| 'error' \| 'validating' \| 'success'` | — |
#### FormItemRule
| Name | Description | Type | Default |
| ------- | ------------------------------- | --------------------------- | ------- |
| trigger | How the validator is triggered. | ^[enum]`'blur' \| 'change'` | — |
:::tip
If you don't want to trigger the validator based on input events, set the `validate-event` attribute as `false` on the corresponding input type components (``, ``, ``, ...).
:::
### FormItem Slots
| Name | Description | Type |
| ------- | --------------------------------------------- | ---------------------------- |
| default | Content of Form Item. | — |
| label | Custom content to display on label. | ^[object]`{ label: string }` |
| error | Custom content to display validation message. | ^[object]`{ error: string }` |
### FormItem Exposes
| Name | Description | Type |
| ------------------------- | -------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| size | Form item size. | ^[object]`ComputedRef<'' \| 'large' \| 'default' \| 'small'>` |
| validateMessage | Validation message. | ^[object]`Ref` |
| validateState | Validation state. | ^[object]`Ref<'' \| 'error' \| 'validating' \| 'success'>` |
| validate | Validate form item. | ^[Function]`(trigger: string, callback?: FormValidateCallback \| undefined) => FormValidationResult` |
| resetField | Reset current field and remove validation result. | ^[Function]`() => void` |
| clearValidate | Remove validation status of the field. | ^[Function]`() => void` |
| setInitialValue ^(2.13.1) | Set initial value for this field. When `resetField` is called, the field will reset to this value. | ^[Function]`(value: any) => void` |
## Type Declarations
Show declarations
```ts
type Arrayable = T | T[]
type FormValidationResult = Promise
// ValidateFieldsError: see [async-validator](https://github.com/yiminghe/async-validator/blob/master/src/interface.ts)
type FormValidateCallback = (
isValid: boolean,
invalidFields?: ValidateFieldsError
) => Promise | void
// RuleItem: see [async-validator](https://github.com/yiminghe/async-validator/blob/master/src/interface.ts)
interface FormItemRule extends RuleItem {
trigger?: Arrayable
}
type Primitive = null | undefined | string | number | boolean | symbol | bigint
type BrowserNativeObject = Date | FileList | File | Blob | RegExp
type IsTuple> = number extends T['length']
? false
: true
type ArrayMethodKey = keyof any[]
type TupleKey> = Exclude
type ArrayKey = number
type PathImpl = V extends
| Primitive
| BrowserNativeObject
? `${K}`
: `${K}` | `${K}.${Path}`
type Path =
T extends ReadonlyArray
? IsTuple extends true
? {
[K in TupleKey]-?: PathImpl, T[K]>
}[TupleKey]
: PathImpl
: {
[K in keyof T]-?: PathImpl, T[K]>
}[keyof T]
type FieldPath = T extends object ? Path : never
// MaybeRef: see [@vueuse/core](https://github.com/vueuse/vueuse/blob/main/packages/shared/utils/types.ts)
// UnwrapRef: see [vue](https://github.com/vuejs/core/blob/main/packages/reactivity/src/ref.ts)
type FormRules | string> = string> =
Partial<
Record<
UnwrapRef extends string ? UnwrapRef : FieldPath>,
Arrayable
>
>
type FormItemValidateState = (typeof formItemValidateStates)[number]
type FormItemProps = ExtractPropTypes
type FormItemContext = FormItemProps & {
$el: HTMLDivElement | undefined
size: ComponentSize
validateMessage: string
validateState: FormItemValidateState
isGroup: boolean
labelId: string
inputIds: string[]
hasLabel: boolean
fieldValue: any
propString: string
addInputId: (id: string) => void
removeInputId: (id: string) => void
validate: (
trigger: string,
callback?: FormValidateCallback
) => FormValidationResult
resetField(): void
clearValidate(): void
setInitialValue: (value: any) => void
}
```