Adobe AD0-E720 Adobe Commerce Front-End Developer Expert Exam Practice Test

Answer : A

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.

Answer : B

To override the parent theme styles, the developer needs to change the web/css/source/_extend.less file in the child theme. This file is used to import and extend the parent theme styles without modifying the original files. The developer can use the @import directive to import the parent theme styles and then use the .lib-css() mixin to override the CSS properties. For example:

@import 'source/_extend.less'; // Import parent theme styles .lib-css(color, red); // Override color property

The web/css/source/_extends.less and web/css/source/_theme.less files are not valid and will not work, as they do not follow the theme structure or the naming convention. Reference: [Theme inheritance], [Extend parent theme styles]

Answer : B

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. Reference: [LESS Mixins], [CSS Animations]

Answer : B

This directory contains various LESS files that define variables, mixins, functions, and styles for common UI elements and components. The Magento_Ui/web/css/source and lib/web/css/source/lib directories are not valid and do not contain the Magento UI library LESS files. Reference: [Magento UI library], [Magento UI library source files]

Answer : C

To completely overwrite _module.less of Orange_Checkout module in a custom theme, the developer should place the file in the Custom/theme/Orange_Checkout/web/css/source directory. This will override the default _module.less file from the Orange_Checkout module and apply the custom styles to the theme. The Custom/theme/Orange_Checkout/frontend/web/css/_module.less and Custom/theme/web/css/source/Orange_Checkout/_module.less paths are not valid and will not work, as they do not follow the theme structure or the module naming convention. Reference: [Theme structure], [Module naming convention]

Answer : A, C

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.

Answer : A, D

To access a view model within an existing block, the developer can use either of the following ways:

$block->getData('view_model'): This method will return the view model object that is assigned to the argument name ''view_model'' in the layout XML file. For example:

<referenceBlock name=''blog_posts_list''> ExampleObjectModel/ExampleObjectModel </referenceBlock>

In the template file, the developer can access the view model object by using:

$block->getData('view_model')

$block->getData('viewModel'): This method will return the view model object that is assigned to the argument name ''viewModel'' in the layout XML file. For example:

<referenceBlock name=''blog_posts_list''> ExampleObjectModel/ExampleObjectModel </referenceBlock>

In the template file, the developer can access the view model object by using:

$block->getData('viewModel')

The following methods are not valid and will not work:

$block->viewModel(): This method does not exist and will cause an error.

$block->getViewHodel(): This method is misspelled and will cause an error.