selenium高级用法
http://docs.seleniumhq.org/docs/04_webdriver_advanced.jsp#
WebDriver: Advanced Usage
Explicit and Implicit Waits
Waiting is having the automated task execution elapse a certain amount of time before continuing with the next step. You should choose to use Explicit Waits or Implicit Waits.
WARNING: Do not mix implicit and explicit waits. Doing so can cause unpredictable wait times. For example setting an implicit wait of 10s and an explicit wait of 15 seconds, could cause a timeout to occur after 20 seconds.
Explicit Waits
An explicit waits is code you define to wait for a certain condition to occur before proceeding further in the code. The worst case of this is Thread.sleep(), which sets the condition to an exact time period to wait. There are some convenience methods provided that help you write code that will wait only as long as required. WebDriverWait in combination with ExpectedCondition is one way this can be accomplished.
WebDriver driver = new FirefoxDriver();
driver.get("http://somedomain/url_that_delays_loading");
WebElement myDynamicElement = (new WebDriverWait(driver, 10))
.until(ExpectedConditions.presenceOfElementLocated(By.id("myDynamicElement")));
This waits up to 10 seconds before throwing a TimeoutException or if it finds the element will return it in 0 - 10 seconds. WebDriverWait by default calls the ExpectedCondition every 500 milliseconds until it returns successfully. A successful return is for ExpectedCondition type is Boolean return true or not null return value for all other ExpectedCondition types.
This example is also functionally equivalent to the first Implicit Waits example.
Expected Conditions
There are some common conditions that are frequently come across when automating web browsers. Listed below are Implementations of each. Java happens to have convienence methods so you don’t have to code an ExpectedCondition class yourself or create your own utility package for them.
- Element is Clickable - it is Displayed and Enabled.
WebDriverWait wait = new WebDriverWait(driver, 10);
WebElement element = wait.until(ExpectedConditions.elementToBeClickable(By.id("someid")));
The ExpectedConditions package (Java) (Python) (.NET) contains a set of predefined conditions to use with WebDriverWait.
Implicit Waits
An implicit wait is to tell WebDriver to poll the DOM for a certain amount of time when trying to find an element or elements if they are not immediately available. The default setting is 0. Once set, the implicit wait is set for the life of the WebDriver object instance.
WebDriver driver = new FirefoxDriver();
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
driver.get("http://somedomain/url_that_delays_loading");
WebElement myDynamicElement = driver.findElement(By.id("myDynamicElement"));
RemoteWebDriver
Taking a Screenshot
import java.io.File;
import java.net.URL;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.remote.Augmenter;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteWebDriver;
public class Testing {
public void myTest() throws Exception {
WebDriver driver = new RemoteWebDriver(
new URL("http://localhost:4444/wd/hub"),
DesiredCapabilities.firefox());
driver.get("http://www.google.com");
// RemoteWebDriver does not implement the TakesScreenshot class
// if the driver does have the Capabilities to take a screenshot
// then Augmenter will add the TakesScreenshot methods to the instance
WebDriver augmentedDriver = new Augmenter().augment(driver);
File screenshot = ((TakesScreenshot)augmentedDriver).
getScreenshotAs(OutputType.FILE);
}
}
Using a FirefoxProfile
FirefoxProfile fp = new FirefoxProfile();
// set something on the profile...
DesiredCapabilities dc = DesiredCapabilities.firefox();
dc.setCapability(FirefoxDriver.PROFILE, fp);
WebDriver driver = new RemoteWebDriver(dc);
Using ChromeOptions
ChromeOptions options = new ChromeOptions();
// set some options
DesiredCapabilities dc = DesiredCapabilities.chrome();
dc.setCapability(ChromeOptions.CAPABILITY, options);
WebDriver driver = new RemoteWebDriver(dc);
AdvancedUserInteractions
The Actions class(es) allow you to build a Chain of Actions and perform them. There are too many possible combinations to count. Below are a few of the common interactions that you may want to use. For a full list of actions please refer to the API docs Java C# Ruby Python
The Advanced User Interactions require native events to be enabled. Here’s a table of the current support Matrix for native events:
| platform | IE6 | IE7 | IE8 | IE9 | FF3.6 | FF10+ | Chrome stable | Chrome beta | Chrome dev | Opera | Android | iOS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Windows XP | Y | Y | Y | n/a | Y | Y | Y | Y | Y | ? | Y [1] | n/a |
| Windows 7 | n/a | n/a | Y | Y | Y | Y | Y | Y | Y | ? | Y [1] | n/a |
| Linux (Ubuntu) | n/a | n/a | n/a | n/a | Y [2] | Y [2] | Y | Y | Y | ? | Y [1] | n/a |
| Mac OSX | n/a | n/a | n/a | n/a | N | N | Y | Y | Y | ? | Y [1] | N |
| Mobile Device | n/a | n/a | n/a | n/a | n/a | ? | n/a | n/a | n/a | ? | Y | N |
| [1] | (1, 2, 3, 4) Using the emulator |
| [2] | (1, 2) With explicitly enabling native events |
Browser Startup Manipulation
Todo
Topics to be included:
- restoring cookies
- changing firefox profile
- running browsers with plugins
Using a Proxy
Internet Explorer
The easiest and recommended way is to manually set the proxy on the machine that will be running the test. If that is not possible or you want your test to run with a different configuration or proxy, then you can use the following technique that uses a Capababilities object. This temporarily changes the system’s proxy settings and changes them back to the original state when done.
String PROXY = "localhost:8080";
org.openqa.selenium.Proxy proxy = new org.openqa.selenium.Proxy();
proxy.setHttpProxy(PROXY)
.setFtpProxy(PROXY)
.setSslProxy(PROXY);
DesiredCapabilities cap = new DesiredCapabilities();
cap.setCapability(CapabilityType.PROXY, proxy);
WebDriver driver = new InternetExplorerDriver(cap);
Chrome
Is basically the same as internet explorer. It uses the same configuration on the machine as IE does (on windows). On Mac it uses the System Preference -> Network settings. On Linux it uses (on Ubuntu) System > Preferences > Network Proxy Preferences (Alternatively in “/etc/environment” set http_proxy). As of this writing it is unknown how to set the proxy programmatically.
Firefox
Firefox maintains its proxy configuration in a profile. You can preset the proxy in a profile and use that Firefox Profile or you can set it on profile that is created on the fly as is shown in the following example.
String PROXY = "localhost:8080";
org.openqa.selenium.Proxy proxy = new org.openqa.selenium.Proxy();
proxy.setHttpProxy(PROXY)
.setFtpProxy(PROXY)
.setSslProxy(PROXY);
DesiredCapabilities cap = new DesiredCapabilities();
cap.setCapability(CapabilityType.PROXY, proxy);
WebDriver driver = new FirefoxDriver(cap);
Opera
Todo
HTML5
Todo
Parallelizing Your Test Runs
Todo
