facebook/php-webdriver — pull request #68 by davidsickmiller (2013-08-07 19:58:39+00:00)
Title: Implemented WebDriverExpectedCondition:alertIsPresent()

Ported this function from the Java API: http://selenium.googlecode.com/git/docs/api/java/org/openqa/selenium/support/ui/ExpectedConditions.html#alertIsPresent()