【Ant Design】Form.Item creates a custom form

I. Overview

Antd is a very powerful UI component library, and Formthe form components in it can basically meet most of our scenarios. But there are also scenarios where custom forms are required.

• Vue2Here we use v-model, combined with the properties of sub-components model, to implement two-way binding of custom components.

• Vue3Here we use v-model, combined with subcomponents update:modelValueto achieve the same function.

• In the middle React+Antd, we use the default incoming onChangeevent referenced by the parent component and call it by the child component.

2. Development and implementation

1. Code

Parent component code:

import { Button, Space, Form, Input, Radio, Switch } from "antd";
import MyBtns from "./components/myBtns";
import { useState, useEffect } from "react";

function Index() {
    const [form] = Form.useForm();
    const [formData, setFormData] = useState<Object>({});

    const layout = {
        name: "myFrom",
        autoComplete: "off",
        labelCol: {
            span: 3,
        },
        wrapperCol: {
            span: 21,
        }
    };
    const initData = {
        title: "IT飞牛的自定义表单",
        item1: "选项-2",
    };

    const onFinish = async (values: Object) => {
        //提交数据
        //...
    }
    const onReset = () => {
        form.resetFields();
    };
    useEffect(() => {
        setFormData(initData);
    }, [])

    return <div>
        {JSON.stringify(formData)}
        <Form
            onFinish={onFinish}
            onValuesChange={(changedValues, allValues) => { setFormData(allValues) }}
            form={form}
            labelAlign="right"
            initialValues={initData}
            style={
   
   {
                "marginTop": "50px"
            }}
            {...layout}
        >
            <Form.Item name="title" label="标题">
                <Input />
            </Form.Item>
            <Form.Item name="item1" label="自定义项">
                <MyBtns />
            </Form.Item>
            <Form.Item wrapperCol={
   
   { offset: 3, span: 21 }}>
                <Space size="middle">
                    <Button htmlType="button" onClick={onReset}>
                        取消
                    </Button>
                    <Button type="primary" htmlType="submit">
                        提交
                    </Button>
                </Space>
            </Form.Item>
        </Form>
    </div >
}

export default Index;

Subcomponent (myBtns.tsx) code:

import { Button, Space } from "antd";

const myBtns = (props: any) => {
    const { value, onChange } = props //value 是form表单中"name"对应的字段值

    const onSelected = (val: string) => {
        onChange(val)
    }

    const getTypeClass = (val: string) => {
        return value == val ? "default" : "dashed";
    }

    return <Space>
        <Button type={getTypeClass("选项1")} onClick={() => onSelected("选项1")}>选项1</Button>
        <Button type={getTypeClass("选项2")} onClick={() => onSelected("选项2")}>选项2</Button>
        <Button type={getTypeClass("选项3")} onClick={() => onSelected("选项3")}>选项3</Button>
    </Space>
}

export default myBtns;

2. Final effect

As you can see, there are two options in the form, the first is Inputa component, and the second is a custom component MyBtns, which has implemented factual updating of data.

3. Principle

Form.ItemvalueEvents will be injected into child elements when rendering onChange.

• value: The value of the form.itemcorresponding nameattribute, which can be used as the default value and return display
• onChange: used to monitor valuechanges in element values ​​and pass them on form.itemso that their values ​​can be obtained through relevant APIs

Note: Properties will not be passed when your field component is wrapped. So the following code will not take effect:

<Form.Item name="input">
  <div>
    <h3>I am a wrapped Input</h3>
    <Input />
  </div>
</Form.Item>