vant/src/col/index.js

import { createNamespace } from '../utils';

const [createComponent, bem] = createNamespace('col');

export default createComponent({
  props: {
    span: [Number, String],
    offset: [Number, String],
    tag: {
      type: String,
      default: 'div',
    },
  },

  computed: {
    gutter() {
      return (this.$parent && Number(this.$parent.gutter)) || 0;
    },

    style() {
      const padding = `${this.gutter / 2}px`;
      return this.gutter ? { paddingLeft: padding, paddingRight: padding } : {};
    },
  },

  methods: {
    onClick(event) {
      this.$emit('click', event);
    },
  },

  render() {
    const { span, offset } = this;
    return (
      <this.tag
        style={this.style}
        class={bem({ [span]: span, [`offset-${offset}`]: offset })}
        onClick={this.onClick}
      >
        {this.slots()}
      </this.tag>
    );
  },
});