vue/src/platforms/web/util/index.ts

Reactive, component-oriented view layer for modern web interfaces.

import { warn } from 'core/util/index'

export * from './attrs'
export * from './class'
export * from './element'

/**
 * Query an element selector if it's not an element already.
 */
export function query(el: string | Element): Element {
  if (typeof el === 'string') {
    const selected = document.querySelector(el)
    if (!selected) {
      __DEV__ && warn('Cannot find element: ' + el)
      return document.createElement('div')
    }
    return selected
  } else {
    return el
  }
}