AD0-E720 Questions and Answers

To initialize a JavaScript component using a data attribute, the developer should use the data-mage-init attribute. This attribute allows the developer to specify the name and configuration of the component in a JSON format. For example:

This will initialize the nav component from the Vendor_Module/js/nav file with the given options. The data-bind and data-init attributes are not valid and will not work, as they are not supported by Magento. References: [JavaScript initialization], [data-mage-init]

To add text to an email template that supports translations, the developer should use the {{trans}} directive with the text enclosed in double quotes. For example:

{{trans “Lorem Ipsum is simply dummy text of the printing”}}

This will render the text as it is, or translate it if a translation file is available for the current locale. If the text contains a variable, the developer should use a placeholder with a percent sign and pass the variable name as an argument. For example:

{{trans “%items items” items=“numItems”}}

This will render the text with the value of numItems replacing the %items placeholder, or translate it if a translation file is available for the current locale. The {{translations}}directive is not valid and will not work. References: [Translate email templates], [Email template syntax]

To customize a JavaScript component that is written as a function, the developer can use option A. This option will use the prototype property of the function to extend its functionality and add new methods or properties. For example:

function Component() { // Component logic }

Component.prototype.customMethod = function() { // Custom method logic };

This will create a new method called customMethod on the prototype of the Component function, which can be accessed by any instance of the Component object. The developer can also override existing methods or properties on the prototype by reassigning them with new values.

Option B is not correct because it will not extend the native JavaScript function, but create a new function that wraps the original function. This will not allow the developer to access or modify the properties or methods of the original function. Option C is not correct because it will not extend the native JavaScript function, but create a new object that inherits from the original function. This will not allow the developer to customize the original function itself, but only its instances.

The styles-l.less and styles-m.less files are two main LESS files that are used to generate CSS files for different devices and screen sizes. The styles-l.less file is used to generate styles-l.css, which contains desktop-specific styles that are applied only when the screen width is greater than 768px. The styles-m.less file is used to generate styles-m.css, which contains basic and mobile-specific styles that are applied for all devices and screen sizes. The other options are not correct and do not reflect the purpose of these files. References: [Stylesheets], [Responsive web design]

To pass JSON data to a JavaScript component while keeping XSS prevention strategies in mind, the developer should use the following options:

• Option A: Use the x-magento-init script tag with the data-mage-init attribute and the JSON.parse function to initialize the component with the JSON data. This option is secure because it does not use any HTML tags or attributes that can be exploited by XSS attacks.
• Option C: Use the text/x-magento-init script tag with the type attribute and the JSON.parse function to initialize the component with the JSON data. This option is secure because it does not use any HTML tags or attributes that can be exploited by XSS attacks.

The following options are not secure and should not be used:

• Option B: Use the script tag with the type attribute and the escapeHtmlAttr function to initialize the component with the JSON data. This option is not secure because it uses the escapeHtmlAttr function, which is meant for escaping HTML attributes, not JSON data. This function can introduce double quotes in the JSON data, which can break the JSON syntax and cause errors.
• Option D: Use the script tag with the type attribute and the escapeJsQuote function to initialize the component with the JSON data. This option is not secure because it uses the escapeJsQuote function, which is meant for escaping JavaScript strings, not JSON data. This function can introduce backslashes in the JSON data, which can break the JSON syntax and cause errors.

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 implement a custom font specifically for emails, the developer needs to do the following steps:

• Add the custom font file to the web/fonts directory of the custom theme.
• Use the @import font function with the url of the custom font from the theme in the /Vendor/Theme/web/css/source/_extend.less file. This will import the custom font and make it available for use in other LESS files. For example:

@import font(‘custom-font’, ‘@{baseDir}fonts/custom-font.ttf’, ‘truetype’);

• Add in the styles to target the elements that require being changed in the /Vendor/Theme/web/css/source/_email.less file. This file is used to define the styles for email templates. The developer can use the .lib-font-face() mixin to apply the custom font to specific selectors. For example:

lib-font-face( @family-name: @custom-font, @font-path: ‘@{baseDir}fonts/custom-font’, @font-weight: normal, @font-style: normal );

h1 { .lib-font-face( @family-name: @custom-font, @font-path: ‘@{baseDir}fonts/custom-font’, @font-weight: normal, @font-style: normal ); }

The /vendor/Theme/web/css/source/_typography.less file is not suitable for implementing a custom font for emails, as it is used for defining global typography styles for web pages. The <head></head> tag is not used for adding fonts in email templates, as it is not supported by most email clients. References: [Custom fonts], [Email templates overview]

The default and production modes are the modes where errors are only written to a log file and not displayed on the screen. This is done to prevent exposing sensitive information to users and attackers. The default mode is the mode that Adobe Commerce runs in by default if no other mode is specified. The production mode is the mode that Adobe Commerce runs in when it is deployed to a live site. The developer can use the following command to check the current mode:

bin/magento deploy:mode:show

The other two options are incorrect because they display errors on the screen as well as writing them to a log file. The developer mode is the mode that Adobe Commerce runs in when it is under development or testing. The developer mode enables enhanced debugging and error reporting features. References: Adobe Commerce Developer Documentation, Adobe Inc.

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