isWebInput(ast) {
    if (!ast.inputProcessed) {
      if (ast.tag === 'textarea') {
        return true
      } else if (ast.tag === 'input') {
        const type = ast.attrs.filter(v => v.name === 'type')[0]
        if (type === undefined) {
          return true
        } else if (type.value === 'text' || type.value === 'password') {
          return true
        }
      }
    }
    return false
  }
for web platform, we wrapped node in a buildin component to prevent IME problem
@param {Object} ast