Getting Started Selenium

Selenium is a web Automation tool which can be used to automate web browsers across many browsers and operating systems.

It has four components.

1.Selenium Integrated Development Environment (IDE)

2.Selenium Remote Control (RC)

3.WebDriver

4.Selenium Grid

Here we will  discuss about Selenium Webdriver which is the current version of Selenium.

Web driver is basically that API which we can use programmatically to control a browser.Using Webdriver we can make powerful tests because WebDriver allows us to use a programming language of our choice in designing our tests.Following programming languages are supported by WebDriver.

# Java

# .Net

#PHP

#Python

#Ruby

Selenium WebDriver can process multilingual commands (sent via Selenese or the Client API) and forwards them directly to the web browser. Webdriver has a built-in implementation of the Firefox driver. For other browsers, you need to plug-in their browser specific drivers to communicate and run the tests.

So here’s a picture of the architecture of Selenium Webdriver.

At the top level there are some bindings and these are language level bindings. These bindings are just implementations in the various languages that we can use to do our automation. So we have a common API that we can use for Selenium that has a common set of commands and we have various bindings for the different languages. These bindings communicate across a common API,this WebDriver API communicate with browsers eventually. This API allows us to have some drivers that interpret commands that are sent across the API. Each one of these drivers knows how to drive the browser that is corresponds to. So the IE driver knows how to use low level details of Internet Explorer and drive it to do things like clicking button, going into pages, getting data from the browser itself, the same thing for Firefox, Chrome and so on.

Suppose we write our test in C# language and we use common selenium API and that C# binding is going to be sending command across this common WebDriver API.Now on the other end is going to be listening a driver which interpret those commands and execute them on the actual browser and then it returns the result backup using the WebDriver API.

Finding Elements

The first thing we need to do is to find the elements on particular page so we can reference them.Some different finders are listed below and we can use anyone of this finders to find an element.

1.ClassName-ClassName is just a CssClassName.If we have an element that has a unique ClassName,we can use that.And  if there were multiple matches,we can index that so we can find the first one or the second one

2.ID-Id is most useful and absolute one.If we have an Id for an element on the page we can use that.This is one of the preferred methods.

3.Name-We can use the name property of an HTML and it’s just like Id.

4.TagName-TagName is pretty general case.This is the actual name of the tag.

5.CssSelector-We can use a CssSelector and this is one of the more advance ways.We can basically use any Css that we would use to identify an element when we created Css.

6.LinkText-LinkText is useful one when we are trying to get a link,we can actually just use the real text of that link

7.PartialLinkText-The PartialLinkText is part of that LinkText,so we can do a partial match on there.

8.Xpath-XPath is one of the most advanced one.This is often what we are going to turn to when none of the other ways work.And we can almost always use some kind of XPath expression to get to a particular element that you want on a page.

Definitely when we are trying to find element on pages,we want to use the most clear one as possible and Id is most absolute and also very clear.But in many cases we have to resort to different ones especially if we don’t have control over that page,if we are testing something that is existing and we can’t modify those pages.

IWebElements

All of the elements that exists on a page will basically be accessed by IWebElement.IWebElement is designed in such a way that it will let us call the methods that we should be able to call on those particular work elements.

Here are some methods on IWebElements

1.Clear

2.Click

3.FindElement

4.FindElements

5.GetAttribute

6.GetCssValue

7.Sendkeys

8.Submit

Properties on IWebElement

1.Displayed

2.Enabled

3.Location

4.Selected

5.Size

6.TagName

7.Text

Verification

In Selenium we can verify some text or something on a page.There is two basic things we can do.One is assert.An assert basically checks to make sure something is true.If an assert fails,the test stops because an assert says ‘this needs to be true in order for me to continue’. The verify actually checks some statement and the test can still continue past that.We can put multiple verification steps in and if it fails,it will log that failure but it will keep going on so we might be able to check multiple things.So the easy way to remember this is,if an assert fails that test has failed and its really an error and if a verify fails,then probably its actually a failing test and then probably it’s actually a failing test case and there might be multiple verification that could fail.So only one assert value but multiple verify failures are allowed.