Table of Contents

Interface IGetsProxyWebDriver

Namespace
CSF.Extensions.WebDriver.Proxies
Assembly
CSF.Extensions.WebDriver.dll

An object which serves as a factory for proxy instances of OpenQA.Selenium.IWebDriver.

public interface IGetsProxyWebDriver

Remarks

Some of the functionality of CSF.Extensions.WebDriver requires the replacement of the WebDriver with a proxy object. The proxy is an object which implements all of the same interfaces as the original WebDriver and behaves in the same way but is augmented with additional functionality.

This proxying process is presently implemented via Castle DynamicProxy: https://www.castleproject.org/projects/dynamicproxy/. This kind of augmentation of objects is typically performed via the decorator pattern: https://en.wikipedia.org/wiki/Decorator_pattern. That pattern is unsuitable here though because it is impossible to know the complete list of interfaces that the original WebDriver object implements until runtime. Without proxies this library would be forced to either:

  • Assume that the WebDriver implements all of Selenium's possible interfaces, possibly claiming to implement some interfaces that the WebDriver does not support
  • Or implement only a minimal set of interfaces: the lowest common denominator, which would result in a less useful WebDriver object

In addition, a new third-party WebDriver which implements as-yet-unknown interfaces would not be able to expose them from a traditional decorator.

A proxy, which is created at runtime, may use reflection to determine all of the interfaces implemented by the WebDriver and implement those same interfaces, whilst adding support for the extra interfaces that are provided by this library.

In practice, this has no effect upon the returned instance of OpenQA.Selenium.IWebDriver; any casting/safe-casting logic which relies on Selenium or other interfaces will continue to work as it has done before. Logic such as the following is still possible if webDriverProxy is a proxy object. 

if(webDriverProxy is IDevTools devToolsDriver)
{
    var session = devToolsDriver.GetDevToolsSession();
    // ...
}

What will not work with a proxy object is casting back to the original OpenQA.Selenium.IWebDriver implementation class type. The following would be false if webDriverProxy were a proxy object: 

var amIChrome = webDriverProxy is ChromeDriver;

Using a functionality-providing object via its interfaces and avoiding reliance upon concrete classes is generally best practice across all of software development so well-written code should not be concerned with this limitation. To cope with the rare scenarios in which this limitation is troublesome, all WebDriver proxies are enhanced with the interface IHasUnproxiedWebDriver. This interface provides functionality to get the original 'unproxied' WebDriver instance. There is also an extension method for the OpenQA.Selenium.IWebDriver interface: Unproxy(IWebDriver) to provide convenient and reliable access to that functionality.

Methods

GetProxyWebDriver(IWebDriver, ProxyCreationOptions)

Gets a proxy object implementing OpenQA.Selenium.IWebDriver as well as all of the other interfaces implemented by the webDriver, enriching it with additional functionality as determined by the options.

IWebDriver GetProxyWebDriver(IWebDriver webDriver, ProxyCreationOptions options)

Parameters

webDriver IWebDriver

The original WebDriver instance to proxy.

options ProxyCreationOptions

Options related to the creation of this proxy.

Returns

IWebDriver

A proxy OpenQA.Selenium.IWebDriver instance.

Remarks

See the remarks upon IGetsProxyWebDriver for more information.

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