antd-form-builder

antd-form-builder

The FormBuilder is a small helper (< 500 lines of source code) for building forms with React and ant.design easily while not preventing you from using the original antd form API. It can not only be used as editable form but also to display readonly information with form layout. It supports both antd v3 and v4 versions.

Examples

You can see the live demo at: https://rekit.github.io/antd-form-builder

Philosophy

The key principle in my mind to create antd-form-builder is it should just help to define form fields and the layout while it doesn't reduce the flexibility of antd's original form API. So in simple patterns you can create a form very easily but if a form is much complicated you can still use the original form API. You can even use antd-form-builder together with the raw API in a mixed way.

Meta Driven

Besides the simplified API which helps to create form easily, the FormBuilder is also very useful if you have meta driven requirement. For example if your form structure needs to be configurable, the meta could be a pure JSON object which can be easily saved and managed separately.

About the New Form API of Ant.Design v4

The new v4 version of ant.design has been released. The form component has been re-written so some API is not backward-compatible now. One of main reasons why antd re-wrote form is for performance improvment of large and complicated forms. But it also lost some flexibilty of creating dynamic forms. In v3, when any form field is changed, the component will be re-rendered because it's hign-order-component based. But in v4 whenever a field is changed the component in which antd form is used will never re-render. That means it's now impossible to create dynamic forms with such code:

<Form>
  {form.getFieldValue('f1') === 'foo' && <Form.Item {...}/>}
</Form>

Instead, you will need similar code like below:

<Form form={form}>
  <Form.Item label="Field1" name="f1">
    <Input />
  </Form.Item>
  <Form.Item shouldUpdate>
    {() =>
      form.getFieldValue("f1") === "foo" && (
        <Form.Item label="Field2" name="f2">
          <Input />
        </Form.Item>
      )
    }
  </Form.Item>
</Form>

Then when you type in 'foo' in the field1 the second field2 will appear.

IMO, this API design looks hacky because the nested form item here is meaningless but the outer one is just a wrapper. The new shouldUpdate property means when other fileds are changed the Form.Item will re-render.

The new API is much less flexible for dynamic forms because you have to put all dynamic logic in the render props. That also means you have to break components into small parts that update separately in render props.

So for the new form API of antd v4, the antd-form-builder can still save much time for building dynamic forms.

New API for antd v4

Though the API of antd-form-builder is backward-compatible, the new form builder still increases the major version to 2.0 since there're some new API for antd v4. If you still use antd v3 you don't need to change any code after upgrading to form builder 2.0. If you use v4, below is the key difference.

1. For class components

You need to create a form instance by FormBuilder.createForm() and pass it to the antd's Form:

import FormBuilder from 'antd-form-builder';

export default class App extends Component {
  form = FormBuilder.createForm(this)
  render() {
    const meta = [{ key: 'name', label: 'Name' }]
    return (
      <Form form={this.form} onValuesChange={this.form.handleValuesChange}>
        <FormBuilder meta={meta} form={this.form} />
      </Form>
    )
  }
}

2. For functional components

You need to create a form with the hook FormBuilder.useForm() and pass it to the antd's Form:

import FormBuilder from 'antd-form-builder'

export default () => {
  const [form] = FormBuilder.useForm()
  const meta = [{ key: 'name', label: 'Name' }]
  return (
    <Form form={form} onValuesChange={form.handleValuesChange}>
      <FormBuilder meta={meta} form={form} />
    </Form>
  )
}

3. Pass form.handleValuesChange to antd's Form's onValuesChange

The form instance created by FormBuilder has a handleValuesChange method, you need to pass it to onValuesChange to antd's Form. This is because in the v4 Form, when fields are changed, the component is not re-renderred. This "urgly" mechanism ensure the wrapper component is always re-renderred when fields change unless you set dynamic: false. The reason why it took a bit long time for the FormBuilder 2.0 is just I also think this API looks a bit stange but unitl now I've not found a better way. However you don't need to worry about using this API because it will not bring incompatabilty issue.

Install

npm install --save-dev antd-form-builder

Usage

The most simple usage is like below (for antd v4):

import React from 'react'
import { Form, Button } from 'antd'
import FormBuilder from 'antd-form-builder'

export default () => {
  const [form] = FormBuilder.useForm()
  const meta = {
    fields: [
      { key: 'username', label: 'User Name' },
      { key: 'password', label: 'Password', widget: 'password' },
    ],
  }

  return (
    <Form form={form}>
      <FormBuilder meta={meta} form={form} />
      <Form.Item wrapperCol={{ span: 16, offset: 8 }}>
        <Button type="primary">Login</Button>
      </Form.Item>
    </Form>
  )
}

Then you get a form:

To see more examples, please go to https://rekit.github.io/antd-form-builder

NOTE: if you use antd v3.x, you may see a warning about module not found: rc-field-form/lib/useForm. It's not a problem because it needs to dynamically detect if the current Form is v3 or v4. If you know a better way without warning, feel free to create a PR.

API Reference

The FormBuilder could be used for both antd v3 and v4, but the API set has a little difference. They will be marked as and .

General API for antd v4

Name	Description
FormBuilder.createForm(context)	Create a form instance for class components to be passed to antd's Form, you need to pass this to it.
FormBuilder.useForm()	Create a form instance for functional components to be passed to antd's Form
form.handleValuesChange	Pass this property from form instance to onValuesChange to antd's Form.

See above section about the introduction of the new API

FormBuilder

Props:

Name	Type	Description
form	object	The antd form instance, unnecessary in viewMode
meta	object/array	The meta for building the form. See below docs for detailed usage
viewMode	bool	In view mode, FormBuild uses viewWidget property for a field, show value directly if viewWidget not defined. And labels are left aligned in the form. Default to false.

meta

meta property tells FormBuilder about all information of form structure. Its basic structure is like below:

const meta = {
  columns: 2, // how many columns to layout fields
  fields: [], // which fields in form
};

If meta is an array, it will be used as fields:

const realMeta = { fields: meta }

If meta is an object without fields property, it's treated as a single field meta, so it will be converted to:

const realMeta = { fields: [meta] }

Properties are listed below:

Name	Type	Default	Description
columns	number	1	How many columns of the form layout.
formItemLayout	object/array	[8, 16]	The labelCol and wrapperCol passed to Form.Item. If it's an array, will be converted to { labelCol: { span: arr[0] }, wrapperCol: { span: arr[1] }}. If a filed has different layout, define it in its own meta.
viewMode	bool	In view mode, FormBuild uses viewWidget property for a field, show value directly if viewWidget not defined. And labels are left aligned in the form. Default to false.
disabled	bool	false	If true, all fields components will be given a disabled property.
initialValues	object	null	Set initialValues to the form, usually used in form which edit values or in viewMode. You can also set initialValue for each field.
fields	array	null	Fields definition for the form. See below info for how to define a field.
gutter	number	0	The gap between columns.

Field meta

Field meta is used to define each field. Each field meta is an object defined in meta.fields. It's a central place to combine parameters to FormBuilder itself, <Form.Item> and getFieldDecorators. All options are listed below:

Name	Type	Default	Description
key	string		Required. The field key. Could be nested like user.name.last. It's just the key value passed to getFieldDecorator(key, options)
name	string/array		Alternative of key. In form v4, if you need nested property for colleced form values like : { name: { first, last } } you can define an array for the name property: ['name', 'first']. If you prefer name.first, use key to define it.
label	string		Label text.
dynamic	boolean	true	If set to true, the change of the field will cause wrapper component to re-render, its default value is true, unless you meet performance issue, you don't need to manually set it to false.
viewMode	bool	false	Whether the field is in view mode. Note if a field is in viewMode but FormBuilder is not, the label in the field is still right aligned.
readOnly	bool	false	Whether the field is readOnly. The difference compared to viewMode is a read-only field is managed by form that is the value is collected when use form.getFieldsValue, but viewMode is not. It is also validated if some rules are configured for the field.
tooltip	string/React Node		If set, there is a question mark icon besides label to show the tooltip.
widget	string/Component	Input	Which component used to render field for editing. The component should be able to be managed by antd form.
widgetProps	object		Props passed to widget.
viewWidget	string/Component	text	Which component used to render field in view mode.
viewWidgetProps	object		Props passed to viewWidget
formItemLayout	object/array	[8, 16]	This applies formItemLayout only to this field rather than which defined in the root meta.
render	function		If provided, this is used for rendering the whole field in both edit and view mode, should render <Form.Item>, getFieldDecorator itself. widget property will be ignored.
renderView	function		If provided, this is used for rendering field value in view mode, viewWidget will be ignored.
colSpan	number	1	How many columns the field should take up.
initialValue	any		The initialValue to be passed to the field widget. In view mode, it's the value to be display.
getInitialValue	func(field, initialValues, form)		Get the initialValue of the field. This may be used to combine multiple fields into one field
disabled	bool	false	If set to true, every widget in field will be given a disabled property regardless of if it's supported.
clear	enum		In multiple columns layout, used to clear left, right or both side fields. Like the clear property in css. Could be left: the field starts from a new row; right: no fields behind the field; both: no other fields in the same row.
forwardRef	bool		If your field widget is a funcional component which doesn't implement forwardRef, set this to true so that React doesn't prompt warning message.
noFormItem	bool	false	By default, each field is wrapped with <Form.Item>, if set to true, it just use `getField
children	ReactNode		The children of widget defined in meta.
required	bool	false	Whether the field is required.
message	string		If a field is required, you can define what message provided if no input. By default, it's ${field.label} is required.
options	array		Only used by select, radio-group. checkbox-group components, explained below.
formItemProps	object		The props passed to <Form.Item>. Below properties are short way to pass props to <Form.Item>. See more from antd's doc
colon	bool	true	Used with label, whether to display : after label text.
extra	string/ReactNode		The extra prompt message. It is similar to help. Usage example: to display error message and prompt message at the same time.
hasFeedback	bool	false	Used with validateStatus, this option specifies the validation status icon. Recommended to be used only with Input.
help	string/ReactNode		The prompt message. If not provided, the prompt message will be generated by the validation rule.
htmlFor	string		Set sub label htmlFor.
labelCol	object		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>.
validateStatus	string		The validation status. If not provided, it will be generated by validation rule. options: 'success' 'warning' 'error' 'validating'
wrapperCol	object		The layout for input controls, same as labelCol.
fieldProps	object		The options to pass to getFieldDecorator(id, options). Below properties are short way to pass options to getFieldDecorator(id, options). See more from antd's doc
getValueFromEvent	function(..args)		Specify how to get value from event or other onChange arguments
getValueProps	function(value)		Get the component props according to field value.
normalize	function(value, prevValue, allValues)		Normalize value to form component
preserve	bool	false	Keep the field even if field removed.
rules	object[]		Includes validation rules. Please refer to "Validation Rules" part for details.
trigger	string	'onChange'	When to collect the value of children node
validateFirst	bool	false	Whether stop validate on first rule of error for this field.
validateTrigger	string / string[]	'onChange'	When to validate the value of children node.
valuePropName	string		Props of children node, for example, the prop of Switch is 'checked'.

Use String Key to Define a Widget

To define the widget for a field, you can use either a string which maps to a widget or a react component directly.

const meta = { key: 'name', label: 'Name', widget: 'input'}
// or
const meta = { key: 'name', label: 'Name', widget: Input }

The reason why you can use a string for widget property is because there are some key-component mapping pre-defined in antd-form-builder/defineAntdWidget.js. Normally you can use a component for widget/viewWidget property of a field meta, but sometimes it's more convenient to use string so that you don't need to import the component while defining meta. And it's especially useful if you want to save meta in some config json.

The predefined components are listed below:

key	Component	meta convention
input	Input
password	Input.Password
textarea	Input.TextArea
number	InputNumber
select	Select	Typically you need to provide children property for Option array to the field meta metioned above. To make it easy to use, you can provide an options array to the field meta, internally it will be convented to children property. Explained below.
date-picker	DatePicker
radio	Radio
checkbox	CheckBox
checkbox-group	CheckBox.Group	Use options for children, same as select.
switch	Switch
radio-group	Radio.Group	Use options for children, same as select. Also you can set buttonGroup to true for tab button style instead of radio style.
button	Button

options

options is a special field meta just mentioned. It's only used for select, checkbox-group or radio-group. You can define children by options in 3 formats:

1. [opt1, opt2, opt3, ...], here value and label are same as opt1, opt2, opt3....

2. [[value1, label1], [value2, label2], ...]

3. [{value: 'v1', label: 'label1'}, {value: 'v2', label: 'label2'}, ...]

Extend FormBuilder: Define Keys for Your Components

Besides built-in pre-defined components, you can define your own by FormBuilder.defineWidget static method like below:

const MyComp = ({ value, onChange}) => {...}
FormBuilder.defineWidget('my-comp', MyComp)

Then you can use it:

const meta = { key: 'comp', label: 'Comp', widget: 'my-comp' }

This mechanism not only makes it easy to define meta easily in your project, but also useful if you want your meta could be pure JSON object.

FormBuilder.defineWidget(key, component, metaConvertor)

Define the key for a widget so that you can use string key in the meta like 'date-picker', 'select'. You can also provide a meta convertor to to provide easier way to give props to the widget.

key

string key to used for the widget

component :

The react component to used in form field

metaConvertor

function, convert field meta to a new meta.

For example: to make it easier to define a Select widget for the field, FormBuilder uses below code internally:

const mapOptions = options => {
  if (!_.isArray(options)) {
    throw new Error('Options should be array in form builder meta.')
  }
  return options.map(opt => {
    if (_.isArray(opt)) {
      return { value: opt[0], label: opt[1] }
    } else if (_.isPlainObject(opt)) {
      return opt
    } else {
      return { value: opt, label: opt }
    }
  })
}

FormBuilder.defineWidget('select', Select, field => {
  if (field.options && !field.children) {
    return {
      ...field,
      children: mapOptions(field.options).map(opt => (
        <Select.Option value={opt.value} key={opt.value}>
          {opt.label}
        </Select.Option>
      )),
    }
  }
  return field
})

Then you can define options for select component with below meta:

const meta = { key: 'select', label: 'Select', options: ['opt1', 'opt2']}

Here options property from meta is converted to chilren property to Select component. You can define options in two mode:

[[value1, label1], [value2, label2]]
// or
[valueAndLabel1, valueAndLabel2]

Otherwise without metaConvertor, you have to define your meta like below:

const meta = {
  key: 'select',
  label: 'Select',
  children: ['opt1', 'opt2'].map(key => <Option key={key}>{key}</Option>),
};

So if you define you own widget, you can give a metaConvertor to provide a convenient way to define field widget.

Contribute

Local development

This project is bootstraped by create-react-library. To start development locally, follow below steps:

# 1. Clone repo
git clone https://github.com/rekit/antd-form-builder.git

# 2. Install dependencies
cd antd-form-builder
npm install

# 3. Run rollup in watch mode
npm start

# 4. Start example dev server (in anther tab)
cd example
npm start

Now, anytime you make a change to your library in src/ or to the example app's example/src, create-react-app will live-reload your local dev server so you can iterate on your component in real-time.

Build examples

cd examples
npm run build

This will build examples into root docs folder which is used as gh-pages root. So after build, commit or pr the changes to the repo.

License

MIT © supnate