10 Salesforce Lightning Interview Questions and Answers in 2023
1. How would you design a custom Lightning component to display data from a Salesforce object?
When designing a custom Lightning component to display data from a Salesforce object, the first step is to create an Apex controller to query the Salesforce object. The controller should use the SOQL query language to retrieve the data from the Salesforce object. The controller should also include methods to handle any user interactions with the component, such as clicking a button or selecting an item from a list.
Once the Apex controller is created, the next step is to create the Lightning component. The component should include an HTML template to define the layout of the component, as well as a JavaScript controller to handle user interactions. The JavaScript controller should use the Apex controller to query the Salesforce object and display the data in the component.
Finally, the component should be tested to ensure that it is working correctly. This can be done by creating a Lightning app that includes the component and testing it in the Lightning App Builder. Once the component is tested and working correctly, it can be deployed to production.
2. Describe the process for creating a Lightning App Builder page.
Creating a Lightning App Builder page involves several steps.
1. First, you need to create a Lightning page. This can be done by navigating to Setup > Lightning App Builder and clicking the “New” button. You will then be prompted to select a page type. Depending on the type of page you are creating, you can choose from a variety of page types, such as Home, Record, App, and others.
2. Once you have selected a page type, you will be taken to the Lightning App Builder page editor. Here, you can drag and drop components onto the page to create the page layout. You can also customize the components by setting properties, such as labels, colors, and other settings.
3. After you have finished creating the page layout, you can save the page and assign it to a profile or permission set. This will allow users with the assigned profile or permission set to access the page.
4. Finally, you can activate the page by clicking the “Activate” button. This will make the page available to users with the assigned profile or permission set.
Creating a Lightning App Builder page is a straightforward process that allows you to quickly create custom pages for your Salesforce org.
3. What is the difference between a Lightning Component and a Lightning Web Component?
The main difference between a Lightning Component and a Lightning Web Component is the technology used to build them. Lightning Components are built using the Aura framework, which is a proprietary framework developed by Salesforce. Lightning Web Components, on the other hand, are built using the open source web standards of HTML, CSS, and JavaScript.
Lightning Components are more feature-rich and have access to the Salesforce platform, such as Apex controllers, Lightning Data Services, and the Lightning Design System. Lightning Web Components are more lightweight and are designed to be more performant. They also have access to the Salesforce platform, but not as much as Lightning Components.
Lightning Components are more suitable for complex applications, while Lightning Web Components are better suited for simpler applications. Both types of components can be used together in the same application, allowing developers to take advantage of the best of both worlds.
4. How would you debug a Lightning component?
When debugging a Lightning component, the first step is to use the Lightning Inspector Chrome extension. This extension allows you to inspect the component hierarchy, view the component attributes, and view the component events. Additionally, you can use the Chrome Developer Tools to debug the JavaScript code of the component.
The next step is to use the Lightning Component Library to view the component's source code. This will allow you to view the component's markup, JavaScript, and CSS. Additionally, you can use the Lightning Component Library to view the component's events and attributes.
The third step is to use the Lightning Component Test Framework to test the component. This will allow you to test the component's functionality and ensure that it is working as expected.
Finally, you can use the Lightning Logger to view the component's log messages. This will allow you to view any errors or warnings that the component is generating.
By using these tools, you can quickly and effectively debug a Lightning component.
5. What is the purpose of the Lightning Data Service?
The Lightning Data Service (LDS) is a powerful tool for Salesforce Lightning developers that allows them to access, create, update, and delete records in Salesforce without writing Apex code. It provides a secure, efficient, and consistent way to access Salesforce data from Lightning components. LDS also helps developers reduce the amount of code they need to write, as it automatically handles server-side logic, such as field-level security, sharing rules, and record-level access. Additionally, LDS helps developers create more efficient and performant applications by reducing the number of server requests and round trips to the server. LDS also helps developers create more responsive applications by providing real-time data updates without the need for manual refreshes.
6. How would you create a custom Lightning event?
Creating a custom Lightning event is a straightforward process.
First, create a Lightning event file in the same directory as the component that will be using the event. The file should be named after the event and should have the .evt extension.
Next, define the event in the file. This is done by using the Lightning Event tag and specifying the name of the event, the type of event (either “COMPONENT” or “APPLICATION”), and any attributes that should be passed along with the event.
Once the event is defined, it can be fired from the component that will be using it. This is done by using the $A.get("e.namespace:eventName") method, where “namespace” is the namespace of the event and “eventName” is the name of the event. The method will return an instance of the event, which can then be fired by using the fire() method.
Finally, the event can be handled by the component that will be receiving it. This is done by using the aura:handler tag and specifying the name of the event, the event type, and the action that should be taken when the event is received.
By following these steps, a custom Lightning event can be created and used in a Salesforce Lightning application.
7. What is the difference between a Lightning App and a Lightning Component?
The main difference between a Lightning App and a Lightning Component is that a Lightning App is a collection of Lightning Components that are used to create a user interface, while a Lightning Component is a reusable piece of code that can be used to create a user interface.
A Lightning App is a container for Lightning Components, and it is used to create a user interface for an application. It is composed of multiple Lightning Components, and it is used to define the layout and navigation of the application. It is also used to define the data that is shared between the components.
A Lightning Component is a reusable piece of code that is used to create a user interface. It is composed of HTML, CSS, and JavaScript, and it is used to create a user interface for an application. It is also used to define the data that is shared between the components.
In summary, a Lightning App is a collection of Lightning Components that are used to create a user interface, while a Lightning Component is a reusable piece of code that can be used to create a user interface.
8. How would you create a custom Lightning Design System theme?
Creating a custom Lightning Design System theme requires a few steps.
First, you need to create a custom theme in the Lightning Design System (LDS) app. This can be done by selecting the “Create Theme” option in the app. You will then be prompted to enter a name for your theme and select the colors you want to use.
Next, you need to create a custom CSS file that will contain the styling for your theme. This file should include the colors you selected in the LDS app, as well as any other styling you want to apply to your theme.
Once you have created the CSS file, you need to upload it to the Salesforce platform. This can be done by going to the “Static Resources” section of the Setup menu and uploading the file.
Finally, you need to add the CSS file to your Lightning component. This can be done by adding the following code to the component’s markup:
Where [theme name] is the name of your custom theme.
Once you have completed these steps, your custom Lightning Design System theme will be ready to use.
9. What is the purpose of the Lightning Out framework?
The purpose of the Lightning Out framework is to enable developers to embed Lightning components into external applications. It provides a way to securely access Salesforce data and functionality from outside the Salesforce platform. It allows developers to create a single page application (SPA) that can be hosted on any web server, and it provides a secure way to access Salesforce data and functionality from outside the Salesforce platform. Lightning Out also provides a way to create a hybrid mobile application that can be deployed to both iOS and Android devices. With Lightning Out, developers can create a single page application that can be hosted on any web server, and it provides a secure way to access Salesforce data and functionality from outside the Salesforce platform. Additionally, Lightning Out provides a way to create a hybrid mobile application that can be deployed to both iOS and Android devices.
10. How would you create a custom Lightning page layout?
Creating a custom Lightning page layout involves several steps.
First, you need to create the Lightning component that will be used in the page layout. This component should include the necessary HTML, CSS, and JavaScript code to render the desired page layout. You can use the Lightning App Builder to create the component, or you can create it from scratch.
Once the component is created, you need to create the page layout. This can be done in the Lightning App Builder. You can drag and drop the components you created into the page layout, and configure them as needed. You can also add other components, such as standard Salesforce components, to the page layout.
Once the page layout is created, you need to assign it to the appropriate profiles. This can be done in the Lightning App Builder, or in the Setup menu.
Finally, you need to test the page layout to make sure it is working as expected. This can be done by logging in as a user with the appropriate profile and navigating to the page layout.
By following these steps, you can create a custom Lightning page layout.