Notes from demo "Selenide in 15 minutes (in Python)" - version with waiting implemented from scratch and conditions as lambdas [ demoed in Minsk on 01.08.2015 ]

selenide_in_15_minutes_demo.py

import contextlib
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException
from selenium.webdriver.common.keys import Keys
import stopit
import time

browser = webdriver.Firefox()


@contextlib.contextmanager
def suppress(*exceptions):
    try:
        yield
    except exceptions:
        pass


def wait_for(finder, condition):
    result = None

    with suppress(NoSuchElementException):
        result = finder()

    with stopit.ThreadingTimeout(4) as ctx_mgr:
        while not (result and condition(result)):
            with suppress(NoSuchElementException):
                time.sleep(0.1)
                result = finder()

    if not ctx_mgr:
        raise stopit.TimeoutException("failed while waiting")

    return result


class WaitingElement(object):
    def __init__(self, css_selector):
        self._locator = css_selector

    def _finder(self):
        return browser.find_element_by_css_selector(self._locator)

    def __getattr__(self, item):
        self.asssure(lambda element: element.is_displayed())
        return getattr(self._finder(), item)

    def assure(self, condition):
        wait_for(self._finder, condition)
        return self


def s(css_selector):
    return WaitingElement(css_selector)


browser.get("http://google.com/ncr")
s("[name='q']").send_keys("selenium", Keys.ENTER)
s(".srg .g:nth-child(1)").assure(lambda element: "Selenium automates browsers" in element.text)  # explicitly waiting of Selenide style (via assure instead of shouldBe)

browser.get("http://google.com/ncr")
s("[name='q']").send_keys("selenium", Keys.ENTER)
s(".srg .g:nth-child(1)").find_element_by_css_selector(".r a").click() # implicitly waiting for visibility of element

browser.quit()