Selenium tricks for CSS and Xpath locators

Learn some CSS rules and how to use CSS selectors and Xpath locators in Selenium.
(1) Id:
An element's id is defined as "[@id='idName']" in Xpath but "#idName" in CSS.
For example, a 'div' element with id 'panel' will be represented as below:

In Xpath locator
//div[@id='panel']

In CSS selector
css=div#panel

(2) Class:
An element's class is defined as "[@class='className']" in Xpath but ".className" in CSS.
For example, a 'div' element with class 'panelClass' will be represented as below:

In Xpath locator
//div[@class='panelClass']
 
In CSS selector
css=div.panelClass

For element with multiple class we need to separate with space(" ") in Xpath and dot(".") in case of CSS. See below example,

In Xpath locator
//div[@class='panelClass1 panelClass2']

In CSS selector
css=div.panelClass1.panelClass2

(3) Any Attributes:
For selecting an element by its any of the attribute(say "name" is an attribute of a 'div' element and "type" in an "input" element) is given below:

In Xpath locator
//div[@name='continue']
//input[@type='button']

In CSS selector
css=div[name='continue']
css=input[type='button']

(4) Direct Child:
A direct child of an element is denoted as "/" in Xpath and ">" in CSS selector. See the example below for a direct child "li" for a "ul" element:

In Xpath locator
//ul/li

In CSS selector
css=ul > li

(5) Child or Subchild:
A direct child of an element is denoted as "//" in Xpath and a wehite-space(" ") in CSS selector. See the example below for a child/subchild "li" for a "ul" element:

In Xpath locator
//ul//li

In CSS selector
css=ul li

Note that "ul li" and "ul > li" are different. If you are confusing please go through this article.

(6) nth Child:
For finding 'nth' child, in Xpath we denote as "[n]" and in CSS we denote as ":nth-of-type(n)". See the below example,

<ol id="drinks">
  <li>Coffee</li>
  <li>Tea</li>
  <li>Milk</li>
  <li>Soup</li>
  <li>Soft Drinks</li>
</ol>

In Xpath locator
//ul[@id='drinks']/li[5]

In CSS selector
css=ul#drinks li:nth-of-type(5)

Also you can use ":nth-child" but the difference between ":nth-child" and ":nth-of-type(n)" is:

li:nth-child(2)
This means, select an element if It is a paragraph element and the second child of a parent.

li:nth-of-type(2)
This means, select the second paragraph child of a parent. This is less conditional.

See here for more details on difference between the above two.

If we want to select the "fifth li element" (Soft Drinks) in this list, we can use the nth-of-type, which will find the fifth li in the list.
css=ul#drinks li:nth-of-type(5)

On the other hand, if we want to get the "fifth element" only if it is a li element, we can use a filtered nth-child which will select again (Soft Drinks) here.
css=ul#drinks li:nth-child(5)

(7) Parent of an element:
Parent of an element can be represented as "/.." in Xpath and ":parent" in CSS selectors. For example, if you want to indicate parent of the list item of class 'blue'

<ul>
  <li class="blue">first</li>
  <li>second</li>
  <li>third</li>
  <li>fourth</li>
 <li>fifth</li>
</ul>

In Xpath locator
//li[@class='blue']/..

In CSS selector
css=li.blue:parent

(8) Next Sibling:
Next sibling is nothing but next adjacent element which is inside the same parent on the page. An adjacent sibling combinator selector allows you to select an element that is directly after another specific element. For example, If you want to select the sibling of "li" element with class "blue" which is 'second' list item,

In Xpath locator
//li[@class='blue']/../li[2]

In CSS selector
css=li.blue + li

Similarly, if you want to indicate 'third' list item, see the below

In Xpath locator
//li[@class='blue']/../li[3]

In CSS selector
css=li.blue + li + li

(9) Match by Innertext:
There is a javascript methodcontains() which can be used to check the inner text of a web element. For example a link with text "Sign in"

In Xpath locator
//a[contains(text(),'Sign in')]
or
//a[contains(string(),'Sign in')]

In CSS selector
css=a:contains('Sign in')

(10) Match by Sub-string:
This is interesting and is described below. With this we can match strings with its partial text. E.g. prefix, suffix or any pattern(sub-string)

    (i) Match a Sub-string(pattern):

    Taking an example of a 'div' with an 'id' that contains the text "pattern"
    <div id="someText_pattern_someOtherText">
    ...
    </div>

    In Xpath locator, we need to use "contains()" to match a sub-string
    //div[contains(@id,'pattern')]

    In CSS selector, we need to use "*=" for matching a sub-string
    css=div[id*='pattern']

    (ii) Match a prefix:

    Taking an example of a 'div' with an 'id' that starts with the text "prefixString"
    <div id="prefixString_pattern_someOtherText">
    ...
    </div>

    In Xpath locator, we need to use "starts-with" to match a prefix
    //div[starts-with(@id,"prefixString")]

    In CSS selector, we need to use "^=" for matching a prefix
    css=div[id^='prefixString']

    (iii) Match a suffix:
    Taking an example of a 'div' with an 'id' that starts with the text "suffixString"
    <div id="prefixString_pattern_sufixString">
    ...
    </div>

    In Xpath locator, we need to use "ends-with" to match a suffix Note that "ends-with()" is a standard XPath 2.0 function only, it won't work if you are using Xpath 1.0 engine
    //div[ends-with(@id,"suffixString")]

    In CSS selector, we need to use "$=" for matching a suffix
    css=div[id$='suffixString']

The summary of sub-string match is listed out in the following table:
 
Match a Sub-string
Match a Prefix
Match a Suffix
Xpath
contains()
starts-with()
ends-with()
 
CSS
*=
^=
$=

Format string for locators
There are many locators for web elements which are of same kind, only they vary with a small difference in index or string such as

"//div[@id='one']/span[text()='jack']" and

"//div[@id='one']/span[text()='john']"

For these web elements we should find a common locator with an input span text.

Let's take an example of a web element,

<ol id="drinks">

  <li>Coffee</li>

  <li>Tea</li>

  <li>Milk</li>

  <li>Soup</li>

  <li>Soft Drinks</li>

</ol>

The locator for the above list items 'Soft Drinks' can be represented as below:


private final String DRINK_ITEM = "ul#drinks li:nth-of-type(5)";// using CSS selector

or

private final String DRINK_ITEM = "//ul[@id='drinks']/li[5]";// using Xpath

For finding 5th 'li' item we can directly use the above locator, but when we want to use 2nd 'li' item or some other item or all 'li' items at a time, then we need to represent the locator in a common way.

    By direct use:

For a list item,

WebElement element= driver.findElement(By.xpath(DRINK_ITEM));

element.doSomething();

Or, 
for all list items,

for (int i = 1; i < count; i++) {

 WebElement element = driver.findElement(By.xpath("//ul[@id='drinks']/li[" + i + "]"));
 element.doSomething();
}

By formatting the locator:
For a list item,
String drinkItem = String.format(DRINK_ITEM, 5);
WebElement element = driver.findElement(By.xpath(drinkItem));
element.doSomething();
 
For multiple list items,

for (int i = 1; i < count; i++) {

 String drinkItem = String.format(DRINK_ITEM, i);
 WebElement element = driver.findElement(By.xpath(drinkItem));
 element.doSomething();

}

If you are still not clear about how to use format string, please see the below examples:

private final String GRID_TABLE_VIEW = "div#panel2content div.table.%s";

private final String RESULT_TABLE_VIEW = "//div[@id='panel1content']//div[%d]/span[text()='%s']";

private final String SPACE_TOGGLE_MENU_OPTION = "ul#spacing_toggle li:nth-of-type(%d)";

String gridTableView = String.format(GRID_TABLE_VIEW, "filterByName");

String resultTableView = String.format(RESULT_TABLE_VIEW, 2, "bill");

String spaceToggleMenuOption = String.format(SPACE_TOGGLE_MENU_OPTION, 3);

/** It will print "div#panel2content div.table.filterByName" */

System.out.println(gridTableView);

/** It will print "//div[@id='panel1content']//div[2]/span[text()='bill']" */

System.out.println(resultTableView);

/** It will print "ul#spacing_toggle li:nth-of-type(3)" */

System.out.println(spaceToggleMenuOption);

Get name of test method in teardown

Sometimes we need name of the test method that has just executed in the tear down method for various purposes such as:

    If you take screenshot in tear down and want to give last executed method name as a part of screenshot name.
    May be someone want to track something in the log with the test method information.
    If you have different classes containing test methods and tear down method, and you want to use test method information in tear down method.

@AfterMethod

public void yourTearDownMethod(ITestResult result) {

  System.out.println("method name:" + result.getMethod().getMethodName();

}

Dealing with web elements by different locators

Let’s consider the following sample HTML code snippet as a reference point.

    <!DOCTYPE HTML>

    <html>

        <head>

            <script type="text/javascript">

                function jsFunction(){

                    alert("Welcome to Selenium UI Automation Testing !");

                }

            </script>

        </head>

        <body>

            <input type="submit" id="webButton" onclick="jsFunction()" value="Click It" />

            <a href="http://aksahu.blogspot.in/">Go Home</a>

        </body>

    </html>

Lets start by taking example of any of the selenium command say "click"

You can use same fashion for any of the selenium command like i am using for click.

The click command emulates a click operation for a link, button, checkbox or radio button. It takes a locator (an identifier for which HTML element the command refers to) as an argument.


Using Selectors with Click Command:

xpath
This allows clicking on an element using an XPath expression. Example :
selenium.click("xpath=//input[@name=webButton' and @type='submit']");

css
CSS locator is used with Selenium commands to uniquely identify an object or element on a web page. Example,
selenium.click("css=input[name=webButton]”);

name
The name selector is used to click the first element with the specified @name attribute. Example,
selenium.click("name=webButton”);
or
selenium.click("webButton");

id
This allows click on an element with the specified @id attribute. Example,
selenium.click("id=webButton”);
 
link
This allows clicking on a link element which contains text matching the specified pattern. Example,

selenium.click("link=Go Home”);