ant-design/components/form/index.en-US.md
二货机器人 8e3c828c9f
feat: Form.List support initialValue (#27872)
* feat: upport initialValue List

* docs: Update doc
2020-11-19 14:29:57 +08:00

20 KiB

category type cols title cover
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
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
component Set the Form rendering element. Do not create a DOM node for false ComponentType | false form
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 -
initialValues Set value by Form initialization or reset object -
labelAlign The 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 -
preserve Keep field value even when field removed boolean true 4.4.0
requiredMark Required mark style. Can use required mark or optional mark. You can not config to single Form.Item since this is a Form level config boolean | optional true 4.6.0
scrollToFirstError Auto scroll to first failed field when submit boolean 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 -
onFieldsChange Trigger when field updated function(changedFields, allFields) -
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 }) -
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 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. ReactNode -
hidden Whether to hide Form.Item (still collect and validate value) boolean false
htmlFor Set sub label htmlFor string -
initialValue Config sub default value. Form initialValues get higher priority when conflict string - 4.2.0
label Label text ReactNode -
labelAlign The 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 which will not affect nest Item. If both exists, use Item first object -
messageVariables default validate filed info Record<string, string> - 4.7.0
name Field name, support array NamePath -
normalize Normalize value from component value before passing to Form instance (value, prevValue, prevValues) => any -
noStyle No style for true, used as a pure field control boolean false
preserve Keep field value even when field removed boolean true 4.4.0
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
tooltip Config tooltip info ReactNode | TooltipProps & { icon: ReactNode } - 4.7.0
trigger When to collect the value of children node string onChange
validateFirst Whether stop validate on first rule of error for this field. Will parallel validate when parallel cofigured boolean | parallel false parallel: 4.5.0
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 which will not affect nest Item. 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.

dependencies shouldn't be used together with shouldUpdate. Since it may cause chaos in updating logic.

dependencies supports Form.Item with render props children since 4.5.0.

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.

messageVariables

You can modify the default verification information of Form.Item through messageVariables.

<Form>
  <Form.Item messageVariables={{ another: 'good' }} label="user">
    <Input />
  </Form.Item>
  <Form.Item messageVariables={{ label: 'good' }} label={<span>user</span>}>
    <Input />
  </Form.Item>
</Form>

Form.List

Provides array management for fields.

Property Description Type Default Version
children Render function (fields: Field[], operation: { add, remove, move }) => React.ReactNode -
initialValue Config sub default value. Form initialValues get higher priority when conflict string - 4.9.0
name Field name, support array NamePath -
rules Validate rules, only support customize validator. Should work with ErrorList { validator, message }[] - 4.7.0
<Form.List>
  {fields => (
    <div>
      {fields.map(field => (
        <Form.Item {...field}>
          <Input />
        </Form.Item>
      ))}
    </div>
  )}
</Form.List>

Note: You should not config Form.Item initialValue under Form.List. It always should be configured by Form.List initialValue or Form initialValues.

operation

Some operator functions in render form of Form.List.

Property Description Type Default
add add form item (defaultValue?: any, insertIndex?: number) => void insertIndex: 4.6.0
move move form item (from: number, to: number) => void -
remove remove form item (index: number | number[]) => void number[]: 4.5.0

Form.ErrorList

New in 4.7.0. Show error messages, should only work with rules of Form.List.

Property Description Type Default
errors Error list ReactNode[] -

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 Version
getFieldError Get the error messages by the field name (name: NamePath) => string[]
getFieldInstance Get field instance (name: NamePath) => any 4.4.0
getFieldsError Get the error messages by the fields name. Return as an array (nameList?: NamePath[]) => FieldError[]
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
getFieldValue Get the value by the field name (name: NamePath) => any
isFieldsTouched Check if fields have been operated. Check if all fields is touched when allTouched is true (nameList?: NamePath[], allTouched?: boolean) => boolean
isFieldTouched Check if a field has been operated (name: NamePath) => 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
errors Error messages string[]
name Field name path NamePath[]
touched Whether is operated boolean
validating Whether is in validating boolean
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. You need to set type to enum to enable this 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
validateTrigger Set validate trigger event. Must be the sub set of validateTrigger in Form.Item string | string[]
validator Customize validation rule. Accept Promise as return. See example (rule, value) => Promise
whitespace Failed if only has whitespace boolean

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);
  }
}

How does name fill value when it's array?

name will fill value by array order. When there exists number in it and no related field in form store, it will auto convert field to array. If you want to keep it as object, use string like: ['1', 'name'].

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 opens, 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 is component defaultValue not working when inside Form.Item?

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

Why can not call ref of Form at first time?

ref only receives the mounted instance. please ref React official doc: https://reactjs.org/docs/refs-and-the-dom.html#accessing-refs

Why resetFields will re-mount component?

resetFields will re-mount component under Field to clean up customize component side effects (like async 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 with dynamic field usage. Priority follows the rules:

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

Why onFieldsChange triggers three times on change when field sets 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.

Why Form.List do not support label and need ErrorList to show errors?

Form.List use renderProps which mean internal structure is flexible. Thus label and error can not have best place. If you want to use antd label, you can wrap with Form.Item instead.

Why Form.Item dependencies can not work on Form.List field?

Your name path should also contain Form.List name:

<Form.List name="users">
  {fields =>
    fields.map(field => (
      <React.Fragment key={field.key}>
        <Form.Item name={[field.name, 'name']} {...someRest1} />
        <Form.Item name={[field.name, 'age']} {...someRest1} />
      </React.Fragment>
    ))
  }
</Form.List>

dependencies should be ['users', 0, 'name']