Working with different drivers like HtmlUnitDriver,Internet Explorer Driver,Firefox Driver,

The existing drivers are the ChromeDriver, InternetExplorerDriver, FirefoxDriver, OperaDriver and HtmlUnitDriver. including their relative strengths and weaknesses There is also support for mobile testing via the AndroidDriver, OperaMobileDriver and IPhoneDriver

While working with selenium webdriver you have an option to choose from multiple webdrivers, such as HtmlUnitDriver, FirefoxDriver, InternetExplorerDriver, ChromeDriver and OperaDriver. Each one of them is a separate implementation of the WebDriver interface provided by Selenium.

The first major point to note is that there are two groups of driver implementations. One of those that invoke the actual browser installed on your system and the other that emulates the behavior of another browser. FirefoxDriver, InternetExplorerDriver, ChromeDriver and OperaDriver invoke the actual browser installed on the machine; however the HtmlUnitDriver emulates other browsers JS behavior.

HtmlUnitDriver

This is currently the fastest and most lightweight implementation of WebDriver. As the name suggests, this is based on HtmlUnit.

·         Fastest implementation of WebDriver

·         A pure Java solution and so it is platform independent.

·         Supports Javascript

 HtmlUnit is a java based framework for testing webApps basically a wrapper around ‘HttpClient’ by Jakarta. HtmlUnit provides UI-Less emulation of browsers to test web applications. The HtmlUnit APIs let you do the typical functions performed in an actual web browser, such as click links, fill forms, invoke web pages, submit values etc. HtmlUnit supports java script and complex AJAX libraries. Javascript is disabled in the HtmlUnitDriver by default, however if it can be enabled if required. The mechanism to enable javascript with the HtmlUnitDriver is as follows:

HtmlUnitDriver MyhtmlDriver = new HtmlUnitDriver();

 MyhtmlDriver.setJavascriptEnabled(true);

OR

HtmlUnitDriver MyhtmlDriver = new HtmlUnitDriver(true);

When enabled, the HtmlUnitDriver emulates the java script behavior of Internet Explorer by default. However we can direct the HtmlUnitDriver to emulate the JavaScript behavior of the browser of our choice by invoking the constructor that accepts the browser version. This can be done as follows:

HtmlUnitDriver MyhtmlDriver = new HtmlUnitDriver(BrowserVersion.Firefox_2);

InternetExplorer Driver

The InternetExplorerDriver is a standalone server which implements WebDriver's wire protocol. This driver has been tested with IE 6, 7, 8 and 9 on appropriate combinations of XP, Vista and Windows 7.

The driver supports running 32-bit and 64-bit versions of the browser. The choice of how to determine which "bit-ness" to use in launching the browser depends on which version of the IEDriverServer.exe is launched. If the 32-bit version of IEDriverServer.exe is launched, the 32-bit version of IE will be launched. Similarly, if the 64-bit version of IEDriverServer.exe is launched, the 64-bit version of IE will be launched.

 The IE driver class ‘InternetExplorerDriver.class’ is located at ‘\org\openqa\selenium\ie\’ directory in the ‘selenium-server-standalone-2.7.0.jar’. To use the InternetExplorerDriver all you need to do is to have the selenium-server-standalone-2.7.0.jar in your CLASSPATH.  The IE driver runs only on windows and supports both 32-bit and 64-bit operations. Depending on the thread that instantiates the InternetExplorerDriver corresponding version of the IE is launched i.e. if the thread instantiating driver is running in 32-bit then the 32-bit version of the IE will be launched and if the thread instantiating driver is running in 64-bit then the 64-bit version of the IE will be launched.

The Internet Explorer driver uses the native or OS-level events to perform various functions on the browser, such as inputs from keyboard and mouse. This approach has both advantages and limitations both. The advantages are that it bypasses the limitations of the Javascript sandbox but there can be issues like the browser window under test might be out of focus.

FirefoxDriver

‘selenium-server-standalone-X.X.X.jar’ contains all the drivers implementing the WebDriver interface of selenium. Hence the 'FirefoxDriver.class' can be found in the ‘\org\openqa\selenium\firefox directory in the selenium-server-standalone-X.X.X.jar. The driver when instantiated is added as an extension to the firefox profile. You can specify the profile with which you want to load firefox session. If no profile is specified then the driver creates an anonymous profile by default.

A profile can be created for the firefox driver as follows:

FirefoxProfile myProfile = new FirefoxProfile();

Multiple operations can be performed on the newly created profile, such as:

myProfile.addExtension(File);

myProfile.clean();

myProfile.getPort();

myProfile.setPort(int port);

myProfile.enableNativeEvents();

myProfile.setPreference(String key, String value); etc...

After creating the your profile you can pass the profile while creating the driver instance as follows:

WebDriver myFireFoxDriver = new FirefoxDriver(myProfile);

This driver is faster than the InternetExplorerDriver and executes the test in real Firefox web browser.