Helium文档8-WebUI自动化-wait_until等待元素出现

前言

wait_until等待某个条件为真才继续往下执行。默认的超时时间为10s，每0.5查询一次，这俩参数选填。可以设置超时时间和轮询间隔。

可以作为添加后校验元素是否存在的场景

入参介绍

def wait_until(condition_fn, timeout_secs=10, interval_secs=0.5):
   """
   :param condition_fn: A function taking no arguments that represents the \
   condition to be waited for.
   :param timeout_secs: The timeout, in seconds, after which the condition is \
   deemed to have failed.
   :param interval_secs: The interval, in seconds, at which the condition \
   function is polled to determine whether the wait has succeeded.

   Waits until the given condition function evaluates to true. This is most
   commonly used to wait for an element to exist::

      wait_until(Text("Finished!").exists)

   More elaborate conditions are also possible using Python lambda
   expressions. For instance, to wait until a text no longer exists::

      wait_until(lambda: not Text("Uploading...").exists())

   ``wait_until`` raises
   :py:class:`selenium.common.exceptions.TimeoutException` if the condition is
   not satisfied within the given number of seconds. The parameter
   ``interval_secs`` specifies the number of seconds Helium waits between
   evaluating the condition function.
   """
   _get_api_impl().wait_until_impl(condition_fn, timeout_secs, interval_secs)

举例说明

wait_until(Text("Finished!").exists)  # 等待直到给定的条件函数评估为true。 这是最通常用于等待元素存在，失败后直接报错

wait_until(lambda: not Text("Uploading...").exists())  # 例如，等待直到文本不再存在：