Free Adobe AD0-E720 Practice Exam with Questions & Answers | Set: 2

To override the core Magento UI library dropdowns in a custom theme, the developer needs to create a file named _dropdowns.less in the /web/css/source directory of the theme. This file will override the default _dropdowns.less file from the lib/web/css/source/lib directory and apply the custom styles to the dropdown elements. The lib/web/css/source/_dropdowns.less and /web/css/source/lib/_dropdowns.less files are not valid and will not work, as they do not follow the theme structure or the naming convention. References: [Dropdowns], [Theme structure]

To register a new page layout in a custom theme, the developer needs to create a layouts.xml file in the app/design/frontend///Magento_Theme/layout directory. The layouts.xml file should contain the element with the id, label, and file attributes. The id attribute is used to reference the layout in other layout files, the label attribute is used to display the layout name in the admin panel, and the file attribute is used to specify the path to the layout file relative to the web directory of the theme. The app/design/frontend///layouts.xml and app/design/frontend///Magento_Theme/layouts.xml files are not valid and will not work. References: [Create a new page layout], [layouts.xml]

Option A is the correct way to initialize a JS component via Layout XML in a custom reference block. The x-magento-init tag is used to specify the component name and the options. Option B is incorrect because it uses the data-mage-init attribute, which is only valid for HTML elements. Option C is incorrect because it uses the x-magento-component tag, which is deprecated and should not be used.

https://developer.adobe.com/commerce/frontend-core/

https://experienceleague.adobe.com/docs/certification/program/technical-certifications/ac/ac-expert/ac-e-fedeveloper0623.html?lang=en

After compiling the .less file into a .css file, the result of the code above will be option B. This is because the .less file uses a mixin called .animation() that takes two parameters: the name of the animation and the duration. The mixin defines a set of vendor-prefixed properties for the animation and assigns them the values of the parameters. For example:

animation(@name; @duration) { -webkit-animation-name: @name; -webkit-animation-duration: @duration; -moz-animation-name: @name; -moz-animation-duration: @duration; animation-name: @name; animation-duration: @duration; }

When the mixin is called with the values “fade” and “2s”, it will generate the following CSS code:

-webkit-animation-name: fade; -webkit-animation-duration: 2s; -moz-animation-name: fade; -moz-animation-duration: 2s; animation-name: fade; animation-duration: 2s;

Option A is not correct because it does not use the vendor prefixes for the animation properties. Option C is not correct because it uses the wrong values for the animation name and duration. References: [LESS Mixins], [CSS Animations]

CSS critical path is a feature that improves the time of first render of the pages by inlining the CSS rules that are required to render the above-the-fold content of the page. This reduces the number of requests and bytes that need to be downloaded before the page is rendered. CSS critical path can be enabled in the Admin Panel by navigating to Stores > Configuration > Advanced > Developer > CSS Settings and setting Enable CSS Critical Path to Yes. References: Adobe Commerce Developer Documentation, Adobe Inc.