Conquer Your Salesforce Lightning Interview: A Comprehensive Guide to Aura Components and Beyond

Are you getting ready for a Salesforce Lightning interview? Are you feeling confused by the huge number of ideas and frameworks? Don’t worry, fellow Trailblazer! This detailed guide, which I personally wrote, will give you the knowledge and confidence to ace your interview.

Let’s dive into the heart of Salesforce Lightning, exploring the intricacies of Aura components and delving into the world of Lightning Web Components (LWCs) We’ll tackle key interview questions, uncover hidden gems, and provide you with the tools to showcase your expertise

Buckle up, it’s time to unleash your inner Lightning master!

1. The Lightning Frameworks: A Tale of Two Components

11 Aura Components The Legacy Powerhouse

• What are they? Aura components, the veterans of the Lightning scene, are built using the Aura framework. They offer a robust set of features and are highly customizable.

• How can we extend any component? To extend an Aura component, simply set the extensible attribute of the parent component to true This allows child components to inherit all the helper methods and attributes of the parent

• Calling JS controller methods A Breeze

  • From one to another To call a JS controller method from another within an Aura component use the $A.enqueueAction() method. This ensures asynchronous execution, preventing conflicts.

  • Passing values with hyperlinks: Use the onclick event and the data attribute to send values to the JS controller through a hyperlink. This allows seamless data transfer between components.

• Aura in Visualforce Pages: A Bridge Between Worlds

  • Adding Aura components: To integrate Aura components into Visualforce pages, utilize the apex:includeLightning component. This establishes a connection between the two frameworks.

  • Making and referring to Lightning apps: In a Lightning app, list the dependencies of your components, and then in your Visualforce page, link to that app. This ensures proper component loading and functionality.

  • JavaScript magic: Use the $Lightning.createComponent() function to dynamically create Aura components within your Visualforce pages. This unlocks a world of dynamic possibilities.

• Deactivating paste functionality: To prevent pasting in an Aura component’s input field, use the onpaste event and the event.preventDefault() method. This ensures data integrity and user experience.

• Accessing current user information: Retrieve the current user’s name and profile name without Apex by utilizing the force:recordData component. This provides efficient data access within your components.

• Data binding: A Two-Way Street

  • Parent-child and vice versa: Aura components boast two-way data binding, meaning changes in parent or child components are reflected in the other. This simplifies data management and enhances component communication.

  • Examples galore: Explore the provided examples to witness the power of data binding in action. Observe how changes in one component automatically update the other, demonstrating the seamless flow of information.

• @AuraEnabled: The Apex Gateway

  • Unlocking remote controller actions: Use the @AuraEnabled annotation on Apex class static methods to make them accessible as remote controller actions within your Lightning components. This bridges the gap between Apex and Lightning, enabling powerful server-side functionality.

  • Serializing instance methods and properties: Apply the @AuraEnabled annotation to Apex instance methods and properties to make them serializable when returned as data from a server-side action. This ensures proper data transfer between Apex and Lightning components.

• Default values: Beyond Hardcoding

  • Leveraging attributes and custom labels: Utilize the values of other attributes or custom labels as default values for attributes within your Aura components. This eliminates the need for hardcoding and promotes flexibility.

  • Examples in action: Explore the provided examples to see how default values can be dynamically set using other attributes or custom labels, showcasing the power of dynamic data binding.

• Restricting component usage: Keeping it Object-Specific

  • Sfdc:objects and sfdc:object tags: To restrict an Aura component’s usage to specific Salesforce objects, leverage the sfdc:objects and sfdc:object tags within your design file. This ensures that components are only used where they are intended, enhancing data integrity and user experience.

1.2 Lightning Web Components: The New Frontier

• LWC lifecycle hooks: A Sequential Journey

  • constructor(): The foundation of your LWC, where initial setup and data fetching occur.

  • connectedCallback(): Invoked when the component is inserted into the DOM, providing an opportunity to interact with the DOM and perform asynchronous operations.

  • renderedCallback(): Called after the component is rendered, allowing for DOM manipulation and post-rendering tasks.

  • render(): The heart of your LWC, where the component’s HTML template is defined.

  • disconnectedCallback(): Invoked when the component is removed from the DOM, providing an opportunity for cleanup tasks.

  • errorCallback(error, stack): Handles errors that occur during the component’s lifecycle.

• @wire: Tapping into the Apex Power

  • Data retrieval made easy: Use the @wire decorator to fetch data from Apex methods directly within your LWCs. This simplifies data access and streamlines component development.

  • Troubleshooting tips: If you encounter issues retrieving data, ensure that the cacheable property is set to true in conjunction with the @AuraEnabled annotation in your Apex method. This enables proper data caching and retrieval.

• VF to LWC: A Seamless Transition

  • NavigationMixin: Your guiding light: Utilize the NavigationMixin to navigate from an LWC to a Visualforce page. This provides a smooth and efficient way to transition between different UI elements.

• Passing data between LWCs and Flows: A Collaborative Effort

  • getRecord: Your data retrieval tool: Use getRecord within your LWC to retrieve field values from the current record. This enables data exchange between LWCs and Flows.

  • Passing values to Apex: The @wire connection: Pass the retrieved field values to an Apex method using the @wire decorator. This establishes a seamless data flow between LWCs, Flows, and Apex.

• Field spanning limit: 5 Levels Deep

  • Referencing relationship fields: Explore relationship fields up to 5 levels deep within your LWCs. This allows you to access and manipulate related data with ease.

• Passing SObject lists to Flows: A Collaborative Effort

  • @api: Your public property declarator: Define list variables with the @api decorator to expose them as public properties within Flows. This enables seamless data transfer between LWCs and Flows.

  • Meta file configuration: Maintain the same meta file configuration as for other data types, ensuring consistency and ease of use.

• LWC Decorators: Your Toolbox of Power

  • @api: Expose component properties and methods for external access.

  • @track: Track changes in component properties and trigger re-rendering when necessary.

  • @wire: Fetch data from Apex methods directly within your LWCs.

• LWC to Aura: A Tale of Two Frameworks

  • NavigationMixin: Your guiding light: Utilize the NavigationMixin to navigate from an LWC to an Aura component. This provides a smooth transition between different UI frameworks.

  • State management: Pass data between LWCs and Aura components using the state property within the NavigationMixin. This ensures proper data transfer and component communication.

• Event Bubbling and Composition: A Tale of Propagation

  • Event.bubbles: Control whether events bubble up through the DOM hierarchy.

  • Event.composed: Determine whether events can pass through shadow boundaries.

• LWC TargetConfigs: A World of Possibilities

  • lightning__AppPage: Integrate your LWCs into Lightning apps.

  • lightning__HomePage: Display your LWCs on the Salesforce Home page.

  • lightning__RecordPage: Embed your LWCs within Salesforce record pages.

  • lightning__Tab: Create custom tabs within Lightning Experience using your LWCs.

  • lightning__FlowScreen: Integrate your LWCs into Flow screens.

2. Beyond the Basics: Unlocking the Secrets of Lightning Components

• SLDS: The Style Master

  • What is it? Salesforce Lightning Design System (SLDS) is the guiding force behind the look and feel of Lightning Experience. It provides design guidelines, HTML blueprints, and style sheets to ensure consistency and a seamless user experience.

  • Custom styles: Expressing Your Creativity

    • Override SLDS styles: When SLDS styles don’t meet your specific needs, create custom CSS files to override them. This allows you to tailor the appearance of your components to match your brand and vision.

    • Encapsulation in LWCs: LWCs provide style encapsulation, preventing style conflicts between components. This ensures that your components maintain their unique appearance regardless of their surroundings.

    • Aura’s global styles: In Aura, styles are prefixed with .THIS to avoid conflicts. However, these styles can affect child components, requiring careful consideration.

• Flexbox and Grid: Layout Wizards

  • **What are they?