Salesforce Updated PDI Exam Questions and Answers by alvie

When multiple triggers are associated to the same object and event, such as before insert or after update, the trigger execution order cannot be guaranteed by Salesforce1. This means that the triggers may run in any order, and the order may change from one execution to another. Therefore, it is not advisable to rely on the order of execution of triggers, or to assume that the order is based on the trigger name, creation date, or modification date. Instead, it is recommended to use a single trigger per object and event, and use helper classes or methods to handle the logic for different scenarios2. References:

• Triggers and Order of Execution - Apex Developer Guide - Salesforce Developers
• Best Practices for Implementing Salesforce Triggers - Salesforce Developers Blog

 The method must be decorated with @AuraEnabled to make it accessible from a Lightning web component. The @AuraEnabled annotation enables client- and server-side access to an Apex controller method. Without this annotation, the Lightning web component can’t call the Apex method. The cacheable=true attribute is optional and indicates whether the method can be cached by the client. The method can return any data type that can be serialized into JSON, such as a JSON object, a JSON array, a primitive type, or a custom type. The method does not need to return a string of a serialized JSON array, as the framework handles the serialization and deserialization automatically. References:

• Lightning Web Components Developer Guide: Call Apex Methods, pages 1-2
• Apex Developer Guide: Annotation AuraEnabled, page 1
• Trailhead: Platform Developer I Certification Study Guide: Lightning Web Components, unit 5

A trace flag is a configuration that specifies the debug level, the start time, the end time, and the log type for a user, an Apex class, or an Apex trigger. The log types are DEVELOPER_LOG, USER_DEBUG, and CLASS_TRACING. A trace flag can be configured for Visualforce, Apex classes, and users to enable logging of their activities and events. For example, a trace flag can be set for a Visualforce page to capture the execution time, view state, and heap size. A trace flag can also be set for an Apex class or trigger to override the default logging level and capture more or less information. A trace flag can also be set for a user to monitor their actions and interactions with Salesforce. A trace flag cannot be configured for Process Builder or outbound messages, as they are not supported log types. References:

• TraceFlag from the Tooling API Developer Guide
• Debug Log Levels from the Salesforce Help
• Set Up Debug Logging from the Salesforce Help

 To make an Apex method available to be wired to a property in a Lightning web component, the developer should use the @AuraEnabled annotation with the cacheable parameter set to true. This indicates that the method is meant to be used in a read-only manner and that the results can be cached on the client. This improves the performance and user experience of the Lightning web component. The @RemoteAction annotation is used for Visualforce remoting, not for Lightning web components. The @AuraEnabled annotation without the cacheable parameter is used for imperative Apex methods that are invoked from a Lightning web component’s JavaScript controller. The @RemoteAction(cacheable=true) annotation is not valid syntax. References: Call Apex Methods, Apex Annotations