vant-weapp/packages/radio-group/index.ts

import { VantComponent } from '../common/component';

VantComponent({
  field: true,

  relation: {
    name: 'radio',
    type: 'descendant',
    linked(target: Weapp.Component) {
      const { value, disabled } = this.data;
      target.set({
        value: value,
        disabled: disabled || target.data.disabled
      });
    }
  },

  props: {
    value: null,
    disabled: Boolean
  },

  watch: {
    value(value) {
      const children = this.getRelationNodes('../radio/index');
      children.forEach(child => {
        child.set({ value });
      });
    },

    disabled(disabled: boolean) {
      const children = this.getRelationNodes('../radio/index');
      children.forEach(child => {
        child.set({ disabled: disabled || child.data.disabled });
      });
    }
  }
});