U.S. Strikes ISIS, Congress Recap, Holiday Spending – NPR
Here’s a breakdown of the HTML code you provided, focusing on the image elements and their attributes:
Overall Structure
The code snippet contains two <img> tags. The first one is a <source> tag used for responsive images, and the second is a standard <img> tag.
1. <source srcset="..."> Tag (responsive Images)
* srcset Attribute: This is the core of responsive images. It provides a comma-separated list of image URLs, each paired with a width descriptor (e.g., 400w, 600w). The browser will choose the most appropriate image based on the device’s screen size and pixel density.
* https://npr.brightspotcdn.com/.../farflungpostcard-hs.jpg 400w - Image URL for a 400-pixel wide viewport.
* https://npr.brightspotcdn.com/.../farflungpostcard-hs.jpg 600w – Image URL for a 600-pixel wide viewport.
*…and so on, up to 1800w.
* data-template Attribute: This attribute defines a template URL that can be used to dynamically generate image URLs with different widths, qualities, and formats. It’s useful for more complex responsive image setups.
* sizes Attribute: This attribute tells the browser how the image will be displayed at different viewport sizes.
* (min-width: 1025px) 650px – If the viewport is 1025 pixels wide or larger, the image will be displayed at 650 pixels wide.
* calc(100vw - 30px) – Otherwise (viewport smaller then 1025px), the image will take up 100% of the viewport width minus 30 pixels (for margins or padding).
* class="img": A CSS class for styling.
* type="image/jpeg": Specifies the image format.
2. <img> Tag (Fallback/Primary Image)
* src Attribute: This is the URL of the image that will be displayed if the browser doesn’t support the <source> tag or if none of the images in the srcset attribute are suitable. in this case,it’s a 1100px wide JPEG image with a quality of 50.
* data-template Attribute: Similar to the <source> tag, this provides a template for generating different image sizes.
* class="img": A CSS class for styling.
* alt=: The alt attribute is missing a value. This is a very important accessibility issue. The alt attribute should provide a text description of the image for screen readers and when the image cannot be displayed.
In Summary
This code implements a responsive image solution. The <source> tag allows the browser to choose the most appropriate image size based on the device’s screen. The <img> tag provides a fallback image for older browsers or situations where the <source> tag isn’t supported.
Important Note: The missing alt text in the <img> tag is a critical accessibility issue that needs to be addressed. Always provide meaningful alt text for images.