import React from 'react';

import { Cascader } from 'antd';

const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    isLeaf: false,
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    isLeaf: false,
  },
];

class LazyOptions extends React.Component {
  state = {
    options,
  };

  onChange = (value, selectedOptions) => {
    console.log(value, selectedOptions);
  };

  loadData = (selectedOptions) => {
    const targetOption = selectedOptions[selectedOptions.length - 1];
    targetOption.loading = true;

    // load options lazily
    setTimeout(() => {
      targetOption.loading = false;
      targetOption.children = [
        {
          label: `${targetOption.label} Dynamic 1`,
          value: 'dynamic1',
        },
        {
          label: `${targetOption.label} Dynamic 2`,
          value: 'dynamic2',
        },
      ];
      this.setState({
        options: [...this.state.options],
      });
    }, 1000);
  };

  render() {
    return (
      <Cascader
        options={this.state.options}
        loadData={this.loadData}
        onChange={this.onChange}
        changeOnSelect
      />
    );
  }
}

export default () => <LazyOptions />;