Microsoft Updated MB-820 Exam Questions and Answers by taran

When creating a test codeunit in Microsoft Dynamics 365 Business Central to write unit test functions, the SubType property (A) of the codeunit should be set to Test. This property is crucial for defining the codeunit's purpose and behavior within the application. By setting the SubType property to Test, you are indicating that the codeunit contains test functions intended to validate the functionality of other parts of the application, such as customizations or new developments. This distinction ensures that the testing framework within Business Central recognizes the codeunit as a container for test functions, allowing it to execute these functions in a testing context, which can include setting up test data, running the tests, and cleaning up after the tests have completed.

To create the Approver field in the Item table using an AL extension, perform the following actions in sequence:

Create an enum object named Approver and include all options.

Create a table extension object for an Item table with an Approver field of enum type named Approver in the fields section.

Create a page extension object that extends the Item Card object. Add the field to the fields section.

Build and extend tables:

To add a new field to an existing table in Business Central using AL extension, you need to define an enumeration (enum) with the possible values for the new field. Then, you create a table extension object where you add the new field and specify its type as the enum you created. This adds the field to the Item table. Finally, you modify the user interface to display the new field by creating a page extension for the Item Card page and adding the new field to it.

Here is the most logical sequence of actions for implementing the Issue Management module in Business Central and exposing the PostIssue method:

Correct Order:

Create a codeunit named "Issue Management Impl." and set the value of Access property to Internal.

This is the first step because Issue Management Impl. is the implementation layer where the actual business logic resides, and setting it to Internal ensures that it is only accessible from within the module, following best practices in encapsulation.

Create a local procedure named PostIssueImpl in the "Issue Management Impl." codeunit.

This step adds the actual PostIssueImpl method, which contains the core logic of posting an issue.

Create a codeunit named "Issue Management" and set the value of Access property to Public.

After defining the implementation logic, you need to create a public-facing Issue Management codeunit to expose the service externally.

Create a PostIssue procedure in the "Issue Management" codeunit, and in it call the PostIssueImpl method.

Lastly, expose the PostIssue method in the Issue Management codeunit, which will internally call the PostIssueImpl method, completing the chain.

In Business Central development using AL (the language for Business Central extensions), the use of access modifiers defines how variables and procedures are accessed within and outside of an object or codeunit.

Access Modifiers in AL:

Public: A public variable can be accessed from any object or codeunit within the same module or extension.

Protected: This restricts access to the current object and objects that inherit from the current object. However, in AL (at least in versions used for Business Central), the Protected access modifier is used with methods but not variables.

Internal: This modifier restricts the visibility to the current extension. This means that variables or methods declared as internal can only be accessed from within the same extension. This is appropriate when you want to provide functionality that is shared within the extension but not exposed externally.

Local: This restricts the variable or method to the current object or method where it is declared. It cannot be accessed from anywhere else, even within the same extension.

Scenario Justification:

In the scenario for Contoso, Ltd., IssueTotal is a global variable in the ISSUE BASE extension, and the ISSUE EXT extension needs to access it. Therefore, the variable cannot be declared as Local, because this would restrict access to just the current object (or method).

Using Public would expose the variable outside of the extension, which is unnecessary because you only want other parts of the extension (specifically the ISSUE EXT extension) to have access.

The best choice in this case is Internal because it restricts access to the variable to within the same extension, which includes the base extension and any dependent extensions like ISSUE EXT. It strikes the right balance between visibility and encapsulation.

Microsoft Dynamics 365 Business Central Developer References:

Access Modifiers in AL: Microsoft's documentation on AL provides the details on access modifiers, where it is specified that internal variables can be accessed within the extension, and the public variable is accessible across all extensions【source: Microsoft Learn on AL Programming】.

Best Practices for AL Development: Business Central development best practices suggest keeping variables internal unless they need to be accessed outside of the current extension【source: Microsoft Learn on AL development guidelines】.