rc-form

What is rc-form?

The rc-form package is a form management library for React. It provides a set of utilities to manage form state, validation, and submission, making it easier to handle complex forms in React applications.

What are rc-form's main functionalities?

Form Creation

This feature allows you to create forms with validation rules. The `createForm` function is used to wrap the form component, and `getFieldDecorator` is used to register form fields with validation rules.

```jsx
import React from 'react';
import { createForm } from 'rc-form';

class MyForm extends React.Component {
  handleSubmit = () => {
    this.props.form.validateFields((err, values) => {
      if (!err) {
        console.log('Received values of form: ', values);
      }
    });
  };

  render() {
    const { getFieldDecorator } = this.props.form;
    return (
      <form onSubmit={this.handleSubmit}>
        <div>
          {getFieldDecorator('username', {
            rules: [{ required: true, message: 'Please input your username!' }],
          })(<input type="text" placeholder="Username" />)}
        </div>
        <button type="submit">Submit</button>
      </form>
    );
  }
}

export default createForm()(MyForm);
```

Field Validation

This feature allows you to add validation rules to form fields. In this example, the email field is validated to ensure it is a valid email address and is required.

```jsx
import React from 'react';
import { createForm } from 'rc-form';

class MyForm extends React.Component {
  handleSubmit = () => {
    this.props.form.validateFields((err, values) => {
      if (!err) {
        console.log('Received values of form: ', values);
      }
    });
  };

  render() {
    const { getFieldDecorator } = this.props.form;
    return (
      <form onSubmit={this.handleSubmit}>
        <div>
          {getFieldDecorator('email', {
            rules: [
              { type: 'email', message: 'The input is not valid E-mail!' },
              { required: true, message: 'Please input your E-mail!' }
            ],
          })(<input type="email" placeholder="Email" />)}
        </div>
        <button type="submit">Submit</button>
      </form>
    );
  }
}

export default createForm()(MyForm);
```

Dynamic Form Fields

This feature allows you to dynamically add form fields. The `addField` method updates the state to add new fields, and `getFieldDecorator` is used to register these fields with validation rules.

```jsx
import React from 'react';
import { createForm } from 'rc-form';

class DynamicForm extends React.Component {
  state = { keys: [] };

  addField = () => {
    const { keys } = this.state;
    this.setState({ keys: keys.concat(keys.length) });
  };

  handleSubmit = () => {
    this.props.form.validateFields((err, values) => {
      if (!err) {
        console.log('Received values of form: ', values);
      }
    });
  };

  render() {
    const { getFieldDecorator } = this.props.form;
    const { keys } = this.state;
    return (
      <form onSubmit={this.handleSubmit}>
        {keys.map(k => (
          <div key={k}>
            {getFieldDecorator(`field-${k}`, {
              rules: [{ required: true, message: 'Please input a value!' }],
            })(<input type="text" placeholder="Dynamic Field" />)}
          </div>
        ))}
        <button type="button" onClick={this.addField}>Add Field</button>
        <button type="submit">Submit</button>
      </form>
    );
  }
}

export default createForm()(DynamicForm);
```

Other packages similar to rc-form

formik

Formik is a popular form management library for React. It provides a set of tools to handle form state, validation, and submission. Compared to rc-form, Formik offers a more modern API and better integration with React hooks.

react-hook-form

React Hook Form is a performant, flexible, and extensible form library for React. It leverages React hooks to manage form state and validation. It is known for its minimal re-renders and easy integration with existing components, making it a strong alternative to rc-form.

redux-form

Redux Form is a library that integrates form state management with Redux. It allows you to manage form state in a centralized Redux store. While it offers powerful features, it can be more complex to set up compared to rc-form.

README

rc-form

React High Order Form Component.

Development

npm install
npm start
open http://localhost:8000/examples/

Feature

• Support react.js and even react-native
• Validate fields with async-validator

Install

Usage

import { createForm, formShape } from 'rc-form';

class Form extends React.Component {
  static propTypes = {
    form: formShape,
  };

  submit = () => {
    this.props.form.validateFields((error, value) => {
      console.log(error, value);
    });
  }

  render() {
    let errors;
    const { getFieldProps, getFieldError } = this.props.form;
    return (
      <div>
        <input {...getFieldProps('normal')}/>
        <input {...getFieldProps('required', {
          onChange(){}, // have to write original onChange here if you need
          rules: [{required: true}],
        })}/>
        {(errors = getFieldError('required')) ? errors.join(',') : null}
        <button onClick={this.submit}>submit</button>
      </div>
    );
  }
}

export createForm()(Form);

Use with React Native

Expo preview

View the source code

Or a quicker version:

import { createForm } from 'rc-form';

class Form extends React.Component {
  componentWillMount() {
    this.requiredDecorator = this.props.form.getFieldDecorator('required', {
      rules: [{required: true}],
    });
  }

  submit = () => {
    this.props.form.validateFields((error, value) => {
      console.log(error, value);
    });
  }

  render() {
    let errors;
    const { getFieldError } = this.props.form;
    return (
      <div>
        {this.requiredDecorator(
          <input
            onChange={
              // can still write your own onChange
            }
          />
        )}
        {(errors = getFieldError('required')) ? errors.join(',') : null}
        <button onClick={this.submit}>submit</button>
      </div>
    );
  }
}

export createForm()(Form);

createForm(option: Object) => (WrappedComponent: React.Component) => React.Component

Option	Description	Type	Default
option.validateMessages	Preseted messages of async-validator	Object	{}
option.onFieldsChange	Called when field changed, you can dispatch fields to redux store.	(props, changed, all): void	NOOP
option.onValuesChange	Called when value changed.	(props, changed, all): void	NOOP
option.mapProps	Get new props transferred to WrappedComponent.	(props): Object	props => props
option.mapPropsToFields	Convert value from props to fields. Used for read fields from redux store.	(props): Object	NOOP
option.fieldNameProp	Where to store the name argument of getFieldProps.	String	-
option.fieldMetaProp	Where to store the meta data of getFieldProps.	String	-
option.fieldDataProp	Where to store the field data	String	-
option.withRef(deprecated)	Maintain an ref for wrapped component instance, use refs.wrappedComponent to access.	boolean	false

Note: use wrappedComponentRef instead of withRef after rc-form@1.4.0

class Form extends React.Component { ... }

// deprecated
const EnhancedForm = createForm({ withRef: true })(Form);
<EnhancedForm ref="form" />
this.refs.form.refs.wrappedComponent // => The instance of Form

// Recommended
const EnhancedForm = createForm()(Form);
<EnhancedForm wrappedComponentRef={(inst) => this.formRef = inst} />
this.formRef // => The instance of Form

(WrappedComponent: React.Component) => React.Component

The returned function of createForm(). It will pass an object as prop form with the following members to WrappedComponent:

getFieldProps(name, option): Object { [valuePropName], [trigger], [validateTrigger] }

Will create props which can be set on a input/InputComponent which support value and onChange interface.

After set, this will create a binding with this input.

<form>
  <input {...getFieldProps('name', { ...options })} />
</form>

name: String

This input's unique name.

option: Object

Option	Description	Type	Default
option.valuePropName	Prop name of component's value field, eg: checkbox should be set to checked ...	String	'value'
option.getValueProps	Get the component props according to field value.	(value): Object	(value) => ({ value })
option.getValueFromEvent	Specify how to get value from event.	(e): any	See below
option.initialValue	Initial value of current component.	any	-
option.normalize	Return normalized value.	(value, prev, all): Object	-
option.trigger	Event which is listened to collect form data.	String	'onChange'
option.validateTrigger	Event which is listened to validate. Set to falsy to only validate when call props.validateFields.	String	String[]
option.rules	Validator rules. see: async-validator	Object[]	-
option.validateFirst	Whether stop validate on first rule of error for this field.	boolean	false
option.validate		Object[]	-
option.validate[n].trigger	Event which is listened to validate. Set to falsy to only validate when call props.validateFields.	String	String[]
option.validate[n].rules	Validator rules. see: async-validator	Object[]	-
option.hidden	Ignore current field while validating or gettting fields	boolean	false
option.preserve	Whether to preserve the value. That will remain the value when the field be unmounted and be mounted again	boolean	false

Default value of getValueFromEvent

function defaultGetValueFromEvent(e) {
  if (!e || !e.target) {
    return e;
  }
  const { target } = e;
  return target.type === 'checkbox' ? target.checked : target.value;
}

Tips

{
  validateTrigger: 'onBlur',
  rules: [{required: true}],
}
// is the shorthand of
{
  validate: [{
    trigger: 'onBlur',
    rules: [{required: true}],
  }],
}

getFieldDecorator(name:String, option: Object) => (React.Node) => React.Node

Similar to getFieldProps, but add some helper warnings and you can write onXX directly inside React.Node props:

<form>
  {getFieldDecorator('name', otherOptions)(<input />)}
</form>

getFieldsValue([fieldNames: String[]])

Get fields value by fieldNames.

getFieldValue(fieldName: String)

Get field value by fieldName.

getFieldInstance(fieldName: String)

Get field react public instance by fieldName.

setFieldsValue(obj: Object)

Set fields value by kv object.

setFieldsInitialValue(obj: Object)

Set fields initialValue by kv object. use for reset and initial display/value.

setFields(obj: Object)

Set fields by kv object. each field can contain errors and value member.

validateFields([fieldNames: String[]], [options: Object], callback: (errors, values) => void)

Validate and get fields value by fieldNames.

options is the same as validate method of async-validator. And add force and scroll. scroll is the same as dom-scroll-into-view's function parameter config.

options.force: Boolean

Defaults to false. Whether to validate fields which have been validated(caused by validateTrigger).

getFieldsError(names): Object{ [name]: String[] }

Get inputs' validate errors.

getFieldError(name): String[]

Get input's validate errors.

isFieldValidating(name: String): Bool

Whether this input is validating.

isFieldsValidating(names: String[]): Bool

Whether one of the inputs is validating.

isFieldTouched(name: String): Bool

Whether this input's value had been changed by user.

isFieldsTouched(names: String[]): Bool

Whether one of the inputs' values had been changed by user.

resetFields([names: String[]])

Reset specified inputs. Defaults to all.

isSubmitting(): Bool (Deprecated)

Whether the form is submitting.

submit(callback: Function) (Deprecated)

Cause isSubmitting to return true, after callback called, isSubmitting return false.

rc-form/lib/createDOMForm(option): Function

createDOMForm enhancement, support props.form.validateFieldsAndScroll

validateFieldsAndScroll([fieldNames: String[]], [options: Object], callback: (errors, values) => void)

props.form.validateFields enhancement, support scroll to the first invalid form field

options.container: HTMLElement

Defaults to first scrollable container of form field(until document).

Notes

• Do not use stateless function component inside Form component: https://github.com/facebook/react/pull/6534

• you can not set same prop name as the value of validateTrigger/trigger for getFieldProps

<input {...getFieldProps('change',{
  onChange: this.iWantToKnow // you must set onChange here or use getFieldDecorator to write inside <input>
})}>

• you can not use ref prop for getFieldProps

<input {...getFieldProps('ref')} />

this.props.form.getFieldInstance('ref') // use this to get ref

or

<input {...getFieldProps('ref',{
  ref: this.saveRef // use function here or use getFieldDecorator to write inside <input> (only allow function)
})} />

Test Case

npm test
npm run chrome-test

Coverage

npm run coverage

open coverage/ dir

License

rc-form is released under the MIT license.