XPath Simplified: How to Build Effective Locators for Testing
While curating asynchronous communication paradigms for web elements in the dynamic landscape of software testing, one needs to ensure high and clear reliability for automation. XPath (XML Path Language) has become one of the most effective and advantageous tools for searching web page elements. But, XPath scares many testers based on its syntax and overall appearance.
This blog will explain what XPath means and how to create good locators for testing in practice. When you complete reading this article, you will appreciate what XPath is, its basic categories and functions, and how you can develop robust XPath locators for use in your automation scripts.
What is XPath?
XPath is the language used when searching for elements within XML and other documents, including HTML. It enables testers to move from one structure of a web page to another and locate elements based on attributes, hierarchy, and patterns in that structure.
Why XPath?
For the following reasons:
- Flexibility: XPath can locate elements based on their attributes, text, position, or relationships with other elements.
- Complex Structure Handling: Suitable for web pages with dynamic content and complex DOM structures.
- Broad Compatibility: Supported by major automation tools like Selenium, Appium, and TestComplete.
- Customizable Queries: Allows for tailored locators to match dynamic and nested elements.
XPath Syntax Basics
XPath expressions follow a specific syntax to identify elements in a document. Below is the basic format:
//tagname[@attribute=’value’]
Example:
<input id=”username” type=”text” />
XPath to locate this element:
//input[@id=’username’]
Key Symbols in XPath:
- // – Select nodes from anywhere in the document.
- / – Selects nodes directly under the parent.
- @ – Selects attributes of elements.
- * – Wildcard is used to match any element or attribute.
- text() – Selects text content of an element.
- contains() – Matches partial values.
- starts-with() – Matches elements starting with a specific value.
- last() – Selects the last element.
Types of XPath
XPath –XML Path Language is a query language mainly used to search nodes of XML documents where one or many conditions can be applied. Within the framework of web automation and testing again, XPath is used to identify objects within HTML documents. XPath expressions are very diverse and can be classified in correspondence to the methods of their usage for elements. Below are the primary types of XPath and how they are used in practice:
- Absolute XPath
Starts from the root (<html>) and provides the full path to an element. It’s long and fragile because it depends on the exact structure.
Example:
/html/body/div/div/input[@id=’username’]
- Relative XPath
It starts from anywhere in the document, making it shorter and more flexible. It’s preferred for test automation.
Example:
//input[@id=’username’]
- XPath Using Attributes
Select elements based on attributes like id, class, name, etc.
Examples:
//input[@id=’username’] //div[@class=’form-container’]
//input[@name=’user’]
- XPath Using Text Content
Select elements based on the text inside them (e.g., buttons, links).
Example:
//button[text()=’Submit’]
//a[contains(text(), ‘Learn’)]
- XPath with contains()
Matches elements where an attribute or text contains a substring.
Example:
//button[contains(@id, ‘submit’)]
//a[contains(text(), ‘Learn’)]
- XPath with starts-with()
Matches elements where an attribute value starts with a specific string.
Example:
//input[starts-with(@id, ‘user’)]
- XPath Using position()
Select elements based on their position in a list.
Example:
//ul/li[position()=2]
- XPath with and/or
Combines multiple conditions.
Examples:
//input[@type=’text’ and @name=’username’]
//input[@type=’text’ or @type=’password’]
- XPath Using Axes
Navigate to elements relative to others using axes like ancestor, descendant, parent, and child.
Examples:
//input[@id=’username’]/ancestor::div
//div[@class=’form’]/descendant::input
- XPath Using the following and preceding
Select elements before or after a given element.
Examples:
//label[text()=’Username’]/following::input
//input[@id=’username’]/preceding::label
Building Effective XPath Locators
Building effective XPath locators is crucial for the stability and maintainability of your automated tests. Good XPath locators are flexible, reliable, and resilient to changes in the webpage structure. Below are key strategies and best practices for building effective XPath locators:
- Use Relative XPath Instead of Absolute XPath
Relative XPath is more flexible and shorter, while absolute XPath can be long and break easily if the page structure changes.
Example (Relative XPath):
//input[@id=’username’]
Example (Absolute XPath):
/html/body/div/div/form/input[@id=’username’]
Tip: Always prefer relative XPath for better maintainability.
- Use Unique and Stable Attributes
– It is usually the most reliable and unique attribute. If it exists, prefer it.
– name, class, data-* attributes are also good choices if they are stable and unique.
Example:
//input[@id=’username’] //button[@name=’submit’]
Tip: Avoid using dynamically generated attributes, like class or style, unless necessary.
- Use contains() for Partial Matches.
If the element’s attributes change dynamically, use the contains() function to match partial values.
Example:
//button[contains(@class, ‘submit’)]
//input[contains(@id, ‘user’)]
It helps avoid brittle locators when class or ID values are partially generated.
- Use text() for Buttons and Links.
If you’re locating buttons, links, or any text-based elements, use the text() function to match based on visible text.
Example:
//button[text()=’Submit’]
//a[contains(text(), ‘Learn More’)]
Tip: Be cautious with localized or dynamic text. If the text changes, consider using contains() or another approach.
- Avoid Using Indexes (position()) unless Necessary
Using position() (e.g., li[1], div[2]) can be fragile as the page’s structure may change. Only use this when you must select a specific element among many similar ones and no other attribute is available.
Example:
//ul/li[position()=2] //div[@class=’container’]/child::p[position()=3]
Tip: Avoid relying on element positions in lists unless necessary, as they can break when new items are added or removed.
- Use Axes for Traversing the DOM
XPath axes allow you to traverse the DOM relative to a given element. It can make your locators more flexible.
- ancestor: Selects ancestor elements of the current node.
- descendant: Selects descendant elements.
- following/preceding: Select elements before or after the current node.
Examples:
//input[@id=’username’]/ancestor::div
//label[text()=’Username’]/following::input
Tip: Use axes to traverse nearby elements without relying on fixed paths.
- Use @ for Attribute-Based Selection
Always specify attributes with @ in XPath when selecting elements based on attributes.
Example:
//input[@type=’text’] //button[@id=’submit-btn’]
- Avoid Overly Complex XPath Expressions
Keep your XPath simple and readable. Avoid deeply nested expressions that are hard to understand and maintain.
Example (Bad):
/html/body/div[1]/div[1]/div[2]/div[1]/ul/li[3]/a
Example (Good):
//ul/li/a[text()=’Learn More]
- Use Logical Operators (and, or) for Complex Conditions
Combine multiple conditions using logical operators like and/or to make more precise locators.
Example:
//input[@type=’text’ and @name=’username’]
//button[@class=’btn’ or @type=’submit’]
- Leverage normalize-space() to Handle Extra Whitespace
Sometimes, extra spaces or newline characters can make text-based matching fail. Use the normalize-space() function to trim whitespace.
Example:
//button[normalize-space(text())=’Submit’]
- Test and Refactor XPath Locators Regularly
Regularly test your locators as the UI evolves. Refactor them when necessary to ensure they remain reliable.
Advanced XPath Techniques
Advanced XPath techniques allow you to build more flexible, powerful, and efficient locators. These techniques are especially helpful in complex web applications, where elements are dynamic and simple locators may not be enough. Below are some advanced XPath techniques to improve the robustness and reliability of your automated tests:
- Navigating Up the DOM
Move upwards in the hierarchy using …
//label[text()=’Email’]/..//input
- Selecting Sibling Elements
Find sibling elements using axes.
//div[@class=’error’]/following-sibling::input
- Child Nodes
Select child nodes explicitly.
//ul/li[1]/a
- Handling Dynamic Elements
Use contains() or starts-with() for elements with dynamic IDs or classes.
//*[contains(@id,’dynamic_’)]
Best Practices for Writing XPath
Writing efficient and maintainable XPath expressions is crucial for web scraping, automated testing, or any other task that involves navigating and extracting data from XML or HTML documents. Below are some best practices for writing XPath:
- Use Specific Paths When Possible
Avoid overly generic paths that can match multiple elements unless necessary. Try to create XPath expressions that uniquely identify the element you’re interested in.
Example: Instead of using //div, specify the class or ID: //div[@class=’main-content’].
- Leverage Unique Identifiers (ID, Class, etc.)
IDs are generally unique within an HTML page, so they are the best option to target elements.
Example: //*[@id=’login-button’] targets an element with id=”login-button”.
Similarly, classes are useful, but remember that multiple elements might share the same class. Be more specific if needed when using classes.
- Use Axis Correctly
XPath has axes like parent::, child::, preceding-sibling::, following-sibling::, etc., which allow you to navigate the document tree more efficiently.
Example:
- //button/parent::div will select the parent <div> of the <button>.
- //a/following-sibling::span selects the <span> that immediately follows an <a>.
- Avoid Overly Broad Search with //
The // operator is powerful but can slow down searches because it looks through the entire document for matches.
Instead of //a, specify a more precise location like //div[@id=’menu’]//a to limit the search to a specific context.
- Use Text Nodes Efficiently
When targeting elements by their text, use the text() function, but ensure that it’s specific enough to avoid ambiguity.
Example: //button[text()= ‘Submit’] targets a button with the exact text “Submit.”
When working with dynamic text content, be aware that whitespace variations could cause mismatches.
Tools for Building and Testing XPath
When working with XPath, having the right tools can significantly improve your workflow and help ensure that your XPath expressions are both correct and efficient. Below are several tools and platforms for building, testing, and debugging XPath expressions:
- Browser Developer Tools: Inspect elements and test XPath queries directly in the browser console.
- XPath Plugins and Extensions: Chrome Extensions like ChroPath, SelectorsHub, and XPath Helper.
- Automation Tools: Selenium IDE, LambdaTest, Katalon Studio, and TestNG.
- Cloud-Based Testing Platforms: Platforms like LambdaTest offer powerful features for scalable and cross-browser testing. With LambdaTest’s cloud-based Selenium Grid, concurrent testing across several operating systems and browsers is made possible. It supports XPath-based element identification, and you can also use an XPath tester to validate and refine XPath expressions, making it easier to test dynamic web applications efficiently.
Common XPath Mistakes to Avoid
Here are a few mistakes that one must avoid:
- Over-Reliance on Absolute XPath: Avoid using absolute XPath, as it can be brittle and prone to breaking when the webpage structure changes. Instead, use relative XPath to create more flexible and maintainable locators.
- Ignoring Dynamic Elements: Many testers fail to account for dynamically generated elements, leading to XPath failures. To make the XPath adaptable, handle dynamic attributes like IDs or classes by using wildcard characters (*) or functions like contains() and starts-with().
- Missing Validations: Always test and validate XPath expressions to ensure they correctly locate the desired elements. Use browser developer tools or XPath evaluators to verify expressions before implementation.
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Conclusion
XPath is a powerful and versatile tool for building reliable locators in automated testing. By understanding its syntax, key functions, and best practices, testers can create robust XPath expressions that are both resilient and maintainable. From navigating complex DOM structures to handling dynamic elements, XPath provides unmatched flexibility, making it an essential skill for modern test automation.
As highlighted in this blog, using relative XPath, leveraging unique attributes, and incorporating functions like contains() and text() can significantly improve locator stability. Advanced techniques such as axes and position-based selection offer even greater precision for complex scenarios.
To maximize efficiency, testers should regularly test and refine their XPath expressions while utilizing tools like browser developer tools, plugins, and automation platforms. Cloud-based testing platforms like LambdaTest can also streamline the process, offering cross-browser testing and Selenium Grid capabilities to validate XPath locators across multiple environments. Avoiding common pitfalls, such as over-reliance on absolute paths and complicated queries, will further enhance the reliability of automation scripts.
Mastering XPath empowers testers to confidently tackle dynamic web applications and ensures automation frameworks’ scalability. By applying the strategies and techniques discussed in this blog, you can build effective locators that stand the test of time and evolving web designs.
