ant-design/components/form/index.en-US.md
Arvin Xu dda650cc7b
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Components Data Entry 1 Form https://gw.alipayobjects.com/zos/alicdn/ORmcdeaoO/Form.svg

High performance Form component with data scope management. Including data collection, verification, and styles.

When to use

  • When you need to create an instance or collect information.
  • When you need to validate fields in certain rules.

API

Form

Property Description Type Default Version
component Set the Form rendering element. Do not create a DOM node for false ComponentType | false form
colon Configure the default value of colon for Form.Item. Indicates whether the colon after the label is displayed (only effective when prop layout is horizontal) boolean true
fields Control of form fields through state management (such as redux). Not recommended for non-strong demand. View example FieldData[] -
form Form control instance created by Form.useForm(). Automatically created when not provided FormInstance -
hideRequiredMark Hide required mark for all form items boolean false
initialValues Set value by Form initialization or reset object -
labelAlign text align of label of all items left | right right
labelCol label layout, like <Col> component. Set span offset value like {span: 3, offset: 12} or sm: {span: 3, offset: 12} object -
layout Form layout horizontal | vertical | inline horizontal
name Form name. Will be the prefix of Field id string -
scrollToFirstError Auto scroll to first failed field when submit false -
size Set field component size (antd components only) small | middle | large -
validateMessages Validation prompt template, description see below ValidateMessages -
validateTrigger Config field validate trigger string | string[] 'onChange' 4.3.0
wrapperCol The layout for input controls, same as labelCol object -
onFinish Trigger after submitting the form and verifying data successfully Function(values) -
onFinishFailed Trigger after submitting the form and verifying data failed Function({ values, errorFields, outOfDate }) -
onFieldsChange Trigger when field updated Function(changedFields, allFields) -
onValuesChange Trigger when value updated Function(changedValues, allValues) -

validateMessages

Form provides default verification error messages. You can modify the template by configuring validateMessages property. A common usage is to configure localization:

const validateMessages = {
  required: "'${name}' is required!",
  // ...
};

<Form validateMessages={validateMessages} />;

Besides, ConfigProvider also provides a global configuration scheme that allows for uniform configuration error notification templates:

const validateMessages = {
  required: "'${name}' is Required!",
  // ...
};

<ConfigProvider form={{ validateMessages }}>
  <Form />
</ConfigProvider>;

Form.Item

Form field component for data bidirectional binding, validation, layout, and so on.

Property Description Type Default Version
colon Used with label, whether to display : after label text. boolean true
dependencies Set the dependency field. See below NamePath[] -
extra The extra prompt message. It is similar to help. Usage example: to display error message and prompt message at the same time string|ReactNode -
getValueFromEvent Specify how to get value from event or other onChange arguments (..args: any[]) => any -
getValueProps Additional props with sub component (value: any) => any - 4.2.0
hasFeedback Used with validateStatus, this option specifies the validation status icon. Recommended to be used only with Input boolean false
help The prompt message. If not provided, the prompt message will be generated by the validation rule. string|ReactNode -
htmlFor Set sub label htmlFor string -
initialValue Config sub default value. Form initialValues get higher priority when conflict string - 4.2.0
noStyle No style for true, used as a pure field control boolean false
label Label text string|ReactNode -
labelAlign text align of label left | right right
labelCol The layout of label. You can set span offset to something like {span: 3, offset: 12} or sm: {span: 3, offset: 12} same as with <Col>. You can set labelCol on Form. If both exists, use Item first object -
name Field name, support array NamePath -
normalize Normalize value from component value before passing to Form instance (value, prevValue, prevValues) => any -
required Display required style. It will be generated by the validation rule boolean false
rules Rules for field validation. Click here to see an example Rule[] -
shouldUpdate Custom field update logic. See below boolean | (prevValue, curValue) => boolean false
trigger When to collect the value of children node string onChange
validateFirst Whether stop validate on first rule of error for this field boolean false
validateStatus The validation status. If not provided, it will be generated by validation rule. options: 'success' 'warning' 'error' 'validating' string -
validateTrigger When to validate the value of children node string | string[] onChange
valuePropName Props of children node, for example, the prop of Switch is 'checked'. This prop is an encapsulation of getValueProps, which will be invalid after customizing getValueProps string 'value'
wrapperCol The layout for input controls, same as labelCol. You can set wrapperCol on Form. If both exists, use Item first object -

After wrapped by Form.Item with name property, value(or other property defined by valuePropName) onChange(or other property defined by trigger) props will be added to form controls, the flow of form data will be handled by Form which will cause:

  1. You shouldn't use onChange on each form control to collect data(use onValuesChange of Form), but you can still listen to onChange.
  2. You cannot set value for each form control via value or defaultValue prop, you should set default value with initialValues of Form. Note that initialValues cannot be updated by setState dynamiclly, you should use setFieldsValue in that situation.
  3. You shouldn't call setState manually, please use form.setFieldsValue to change value programmatically.

dependencies

Used when there are dependencies between fields. If a field has the dependencies prop, this field will automatically trigger updates and validations when upstream is updated. A common scenario is a user registration form with "password" and "confirm password" fields. The "Confirm Password" validation depends on the "Password" field. After setting dependencies, the "Password" field update will re-trigger the validation of "Check Password". You can refer examples.

shouldUpdate

Form updates only the modified field-related components for performance optimization purposes by incremental update. In most cases, you only need to write code or do validation with the dependencies property. In some specific cases, such as when a new field option appears with a filed value changed, or you just want to keep some area updating by form update, you can modify the update logic of Form.Item via the shouldUpdate.

When shouldUpdate is true, any Form update will cause the Form.Item to be re-rendered. This is very helpful for custom rendering some areas:

<Form.Item shouldUpdate>
  {() => {
    return <pre>{JSON.stringify(form.getFieldsValue(), null, 2)}</pre>;
  }}
</Form.Item>

You can ref example to see detail.

When shouldUpdate is a function, it will be called by form values update. Providing original values and current value to compare. This is very helpful for rendering additional fields based on values:

<Form.Item shouldUpdate={(prevValues, curValues) => prevValues.additional !== curValues.additional}>
  {() => {
    return (
      <Form.Item name="other">
        <Input />
      </Form.Item>
    );
  }}
</Form.Item>

You can ref example to see detail.

Form.List

Provides array management for fields.

Property Description Type Default
name Field name, support array NamePath -
children Render function (fields: Field[], operation: { add, remove, move }) => React.ReactNode -
<Form.List>
  {fields => (
    <div>
      {fields.map(field => (
        <Form.Item {...field}>
          <Input />
        </Form.Item>
      ))}
    </div>
  )}
</Form.List>

Form.Provider

Provide linkage between forms. If a sub form with name prop update, it will auto trigger Provider related events. See example.

Property Description Type Default
onFormChange Triggered when a sub form field updates Function(formName: string, info: { changedFields, forms }) -
onFormFinish Triggered when a sub form submits Function(formName: string, info: { values, forms }) -
<Form.Provider
  onFormFinish={name => {
    if (name === 'form1') {
      // Do something...
    }
  }}
>
  <Form name="form1">...</Form>
  <Form name="form2">...</Form>
</Form.Provider>

FormInstance

Name Description Type
getFieldValue Get the value by the field name (name: NamePath) => any
getFieldsValue Get values by a set of field names. Return according to the corresponding structure (nameList?: NamePath[], filterFunc?: (meta: { touched: boolean, validating: boolean }) => boolean) => any
getFieldError Get the error messages by the field name (name: NamePath) => string[]
getFieldsError Get the error messages by the fields name. Return as an array (nameList?: NamePath[]) => FieldError[]
isFieldTouched Check if a field has been operated (name: NamePath) => boolean
isFieldsTouched Check if fields have been operated. Check if all fields is touched when allTouched is true (nameList?: NamePath[], allTouched?: boolean) => boolean
isFieldValidating Check fields if is in validating (name: NamePath) => boolean
resetFields Reset fields to initialValues (fields?: NamePath[]) => void
scrollToField Scroll to field position (name: NamePath, options: [ScrollOptions]) => void
setFields Set fields status (fields: FieldData[]) => void
setFieldsValue Set fields value (values) => void
submit Submit the form. It's same as click submit button () => void
validateFields Validate fields (nameList?: NamePath[]) => Promise

validateFields return sample

validateFields()
  .then(values => {
    /*
  values:
    {
      username: 'username',
      password: 'password',
    }
  */
  })
  .catch(errorInfo => {
    /*
    errorInfo:
      {
        values: {
          username: 'username',
          password: 'password',
        },
        errorFields: [
          { password: ['username'], errors: ['Please input your Password!'] },
        ],
        outOfDate: false,
      }
    */
  });

Interface

NamePath

string | number | (string | number)[]

FieldData

Name Description Type
touched Whether is operated boolean
validating Whether is in validating boolean
errors Error messages string[]
name Field name path NamePath[]
value Field value any

Rule

Rule support config object, and also support function to get config object:

type Rule = RuleConfig | ((form: FormInstance) => RuleConfig);
Name Description Type
enum Match enum value any[]
len Length of string, number, array number
max type required: max length of string, number, array number
message Error message. Will auto generate by template if not provided string
min type required: min length of string, number, array number
pattern Regex pattern RegExp
required Required field boolean
transform Transform value to the rule before validation (value) => any
type Normally string |number |boolean |url | email. More type to ref here string
validator Customize validation rule. Accept Promise as return. example参考 (rule, value) => Promise
whitespace Failed if only has whitespace boolean
validateTrigger Set validate trigger event. Must be the sub set of validateTrigger in Form.Item string | string[]

Migrate to v4

If you are a user of v3, you can ref migrate doc

FAQ

Custom validator not working

It may be caused by your validator if it has some errors that prevents callback to be called. You can use async instead or use try...catch to catch the error:

validator: async (rule, value) => {
  throw new Error('Something wrong!');
}

// or

validator(rule, value, callback) => {
  try {
    throw new Error('Something wrong!');
  } catch (err) {
    callback(err);
  }
}

Why is there a form warning when used in Modal?

Warning: Instance created by useForm is not connect to any Form element. Forget to pass form prop?

Before Modal open, children elements do not exist in the view. You can set forceRender on Modal to pre-render its children. Click here to view an example.

Why component defaultValue not working when inside Form.Item?

Components inside Form.Item with name property will turn into controlled mode, that makes defaultValue does not work anymore. Please try initialValues of Form to set default value.

Why resetFields will re-mount component?

resetFields will re-mount component under Field to clean up customize component side effect(like asyn data, cached state, etc.). It's by design.

Difference between Form initialValues and Item initialValue?

In most case, we always recommend to use Form initialValues. Use Item initialValue only when dynamic field usage. Priority follow the rules:

  1. Form initialValues is the first priority
  2. Field initialValue is secondary *. Not work when multiple Item with same name setting the initialValue

Why onFieldsChange trigger three times on change when field set rules?

Validating is also part of the value updating. It pass follow steps:

  1. Trigger value change
  2. Rule validating
  3. Rule validated

In each onFieldsChange, you will get false > true > false with isFieldValidating.