What is the process for capturing a screenshot of a specific DOM element using Intern JS?

Question

What is the process for capturing a screenshot of a specific DOM element using Intern JS?

I'm currently utilizing intern.js for testing a web application. It allows me to run tests and generate screenshots in case of failures. My goal is to capture a screenshot of a specific element for conducting CSS regression testing with tools like resemble.js. Is this achievable? If so, how can I go about it? Thank you for your help!

css selenium screenshot intern regression-testing

Answer 1

Answer №1

driver.navigate("http://www.google.com");
WebElement logo = driver.findElement(By.id("hplogo"));   

//Take screenshot of entire page
File fullScreenshot = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
BufferedImage  fullImage = ImageIO.read(fullScreenshot);

//Find the location of element on the page
Point position = logo.getLocation();

//Obtain width and height of the element
int elementWidth = logo.getSize().getWidth();
int elementHeight = logo.getSize().getHeight();

//Crop the full page screenshot to extract only the element's screenshot
BufferedImage elementScreenshot = fullImage.getSubimage(position.getX(), position.getY(), elementWidth,
    elementHeight);
ImageIO.write(elementScreenshot, "png", fullScreenshot);

//Save the element screenshot to a specific location on disk
File savedScreenshotLocation = new File("C:\\images\\GoogleLogo_screenshot.png");
FileUtils.copyFile(fullScreenshot, savedScreenshotLocation);

Original source here.

Answer 2

driver.navigate("http://www.google.com");
WebElement logo = driver.findElement(By.id("hplogo"));   

//Take screenshot of entire page
File fullScreenshot = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
BufferedImage  fullImage = ImageIO.read(fullScreenshot);

//Find the location of element on the page
Point position = logo.getLocation();

//Obtain width and height of the element
int elementWidth = logo.getSize().getWidth();
int elementHeight = logo.getSize().getHeight();

//Crop the full page screenshot to extract only the element's screenshot
BufferedImage elementScreenshot = fullImage.getSubimage(position.getX(), position.getY(), elementWidth,
    elementHeight);
ImageIO.write(elementScreenshot, "png", fullScreenshot);

//Save the element screenshot to a specific location on disk
File savedScreenshotLocation = new File("C:\\images\\GoogleLogo_screenshot.png");
FileUtils.copyFile(fullScreenshot, savedScreenshotLocation);

Original source here.

Answer 3

Answer №2

If you're looking to crop an image using Intern, there isn't a direct built-in method for it. The takeScreenshot function in Intern fetches the entire page's screenshot as a base-64 encoded PNG from Selenium's screenshot service. Intern then converts this into a Node buffer before providing it to the user.

To achieve image cropping, you'll need to utilize an external library or tool like png-crop (although my experience with it is limited). Below is some sample code (not tested):

var image;
var size;
var position;

return this.remote
    // ...
    .takeScreenshot()
    .then(function (imageBuffer) {
        image = imageBuffer;
    })
    .findById('element')
    .getSize()
    .then(function (elementSize) {
        size = elementSize;
    })
    .getPosition()
    .then(function (elementPosition) {
        position = elementPosition;
    })
    .then(function () {
        // assuming png-crop is loaded as PNGCrop
        var config = {
            width: size.width,
            height: size.height,
            top: position.y,
            left: position.x
        };
        // Need to return a Promise since PNGCrop.crop is asynchronous
        return new Promise(function (resolve, reject) {
            PNGCrop.crop(image, 'cropped.png', config, function (err) {
                if (err) {
                    reject(err);
                }
                else {
                    resolve();
                }
            });
        });
    })

Answer 4

If you're looking to crop an image using Intern, there isn't a direct built-in method for it. The takeScreenshot function in Intern fetches the entire page's screenshot as a base-64 encoded PNG from Selenium's screenshot service. Intern then converts this into a Node buffer before providing it to the user.

To achieve image cropping, you'll need to utilize an external library or tool like png-crop (although my experience with it is limited). Below is some sample code (not tested):

var image;
var size;
var position;

return this.remote
    // ...
    .takeScreenshot()
    .then(function (imageBuffer) {
        image = imageBuffer;
    })
    .findById('element')
    .getSize()
    .then(function (elementSize) {
        size = elementSize;
    })
    .getPosition()
    .then(function (elementPosition) {
        position = elementPosition;
    })
    .then(function () {
        // assuming png-crop is loaded as PNGCrop
        var config = {
            width: size.width,
            height: size.height,
            top: position.y,
            left: position.x
        };
        // Need to return a Promise since PNGCrop.crop is asynchronous
        return new Promise(function (resolve, reject) {
            PNGCrop.crop(image, 'cropped.png', config, function (err) {
                if (err) {
                    reject(err);
                }
                else {
                    resolve();
                }
            });
        });
    })

What is the process for capturing a screenshot of a specific DOM element using Intern JS?

Answer №1

Answer №2

Similar questions

Add a click event listener to the body element using a button click, without causing it to trigger

Jquery animation in Wordpress without any need for scrolling

Testing the capabilities of AngularJS with e2e testing using the angular-recaptcha library

Embedding the @media tag directly into a class for simplification and to eliminate redundancy

Create a cohesive user experience by implementing the same CSS animation when hovering over two distinct elements

What is the best way to use CSS to connect the tips of shapes for perfect alignment?

Adding -moz & -o prefixes to code that only has -webkit tags can be done by manually duplicating each line of

Expand the table in the initial state by using CSS to collapse the tree

Creating a capsule-shaped button using HTML and CSS:

Interact with elements using Selenium with dynamic target IDs and AJAX

Utilize CSS and Bootstrap to ensure equal-sized responsive images in a row by scaling them down to the same dimensions

The label element in a CSS form is not displaying correctly

The Chrome Selenium driver failed to initialize properly

Issues with the navigation and logo design in bootstrap mode

Learning to use Material-UI: Wrapping a list into columns

What is the best way to set the width of an element to 100% while accounting for padding

Can a javascript code for "Infinite Scroll" be created to manage the back button?

The issue at hand is that one of the JavaScript buttons is functioning properly, while the other is not playing the video as intended. What steps can

Why am I encountering the selenium.common.exceptions.ElementClickInterceptedException error message stating that the element click has been intercepted?

Steps to activate the hyperlink tool in CK editor