antd自定义表单控件

前言

不知不觉使用antd已经接近两年了，可能其中使用的最多的就是表单了，antd自身提供了很丰富的表单组件。单在实际业务中，极大的可能满足不了业务需求，这时候就需要自己写表单控件。

实例

下面是antd官网上的一个示例

import { Form, Input, Select, Button } from 'antd';

const { Option } = Select;

class PriceInput extends React.Component {
  static getDerivedStateFromProps(nextProps) {
    // Should be a controlled component.
    if ('value' in nextProps) {
      return {
        ...(nextProps.value || {}),
      };
    }
    return null;
  }

  constructor(props) {
    super(props);

    const value = props.value || {};
    this.state = {
      number: value.number || 0,
      currency: value.currency || 'rmb',
    };
  }

  handleNumberChange = e => {
    const number = parseInt(e.target.value || 0, 10);
    if (Number.isNaN(number)) {
      return;
    }
    if (!('value' in this.props)) {
      this.setState({ number });
    }
    this.triggerChange({ number });
  };

  handleCurrencyChange = currency => {
    if (!('value' in this.props)) {
      this.setState({ currency });
    }
    this.triggerChange({ currency });
  };

  triggerChange = changedValue => {
    // Should provide an event to pass value to Form.
    const { onChange } = this.props;
    if (onChange) {
      onChange(Object.assign({}, this.state, changedValue));
    }
  };

  render() {
    const { size } = this.props;
    const { state } = this;
    return (
      <span>
        <Input
          type="text"
          size={size}
          value={state.number}
          onChange={this.handleNumberChange}
          style={{ width: '65%', marginRight: '3%' }}
        />
        <Select
          value={state.currency}
          size={size}
          style={{ width: '32%' }}
          onChange={this.handleCurrencyChange}
        >
          <Option value="rmb">RMB</Option>
          <Option value="dollar">Dollar</Option>
        </Select>
      </span>
    );
  }
}

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

  checkPrice = (rule, value, callback) => {
    if (value.number > 0) {
      callback();
      return;
    }
    callback('Price must greater than zero!');
  };

  render() {
    const { getFieldDecorator } = this.props.form;
    return (
      <Form layout="inline" onSubmit={this.handleSubmit}>
        <Form.Item label="Price">
          {getFieldDecorator('price', {
            initialValue: { number: 0, currency: 'rmb' },
            rules: [{ validator: this.checkPrice }],
          })(<PriceInput />)}
        </Form.Item>
        <Form.Item>
          <Button type="primary" htmlType="submit">
            Submit
          </Button>
        </Form.Item>
      </Form>
    );
  }
}

const WrappedDemo = Form.create({ name: 'customized_form_controls' })(Demo);

ReactDOM.render(<WrappedDemo />, mountNode);

示例代码很多，但其关键点就几点,getFieldDecorator处理后的组件会带有两个属性，value,onChange,value用于传入默认值，onChange用于回传数据给表单。

1.传入

在 getDerivedStateFromProps 中value关联到组件

static getDerivedStateFromProps(nextProps) {
    // Should be a controlled component.
    if ('value' in nextProps) {
      return {
        ...(nextProps.value || {}),
      };
    }
    return null;
  }

1.传出

在 getDerivedStateFromProps 中value关联到组件

triggerChange = changedValue => {
    // Should provide an event to pass value to Form.
    const { onChange } = this.props;
    if (onChange) {
      onChange(Object.assign({}, this.state, changedValue));
    }
  };