Pass the Microsoft Certified: Dynamics 365 Business Central Developer Associate MB-820 Questions and answers with Dumpstech

When updating the base application table using a table extension in Microsoft Dynamics 365 Business Central, certain properties of table fields can be modified to meet new requirements, such as regulatory changes. The DecimalPlaces property (B) is one such property that can be adjusted in a table extension. This property determines the number of decimal places that are displayed and stored for decimal fields in the table. Adjusting the DecimalPlaces property can be particularly useful when dealing with financial data and tax calculations that require precision to meet new tax tiers set by a regulator. It's important to note that not all properties can be modified in a table extension; for example, the CalcFormula property (A) cannot be changed as it affects how the field's value is calculated, which could have significant implications on the base application's logic.

Handler methods are used in tests to simulate user interactions, such as responding to dialogs, confirmation messages, or option selections. Since you need to simulate the user interaction of selecting a posting option (Ship, Invoice, Ship & Invoice), a Handler method would be the appropriate choice for capturing this kind of user input.

Normal attribute and Test attribute are used for marking methods for test execution, but they do not simulate user interaction, making Handler method the correct answer.

For more details, see the Microsoft Docs on Test Codeunits and Handler Methods.

Developed by using any coding language: Connect app

Developed by using AL language in Visual Studio Code: Add-on app

In Microsoft Dynamics 365 Business Central, there are distinct types of applications that can be developed: Connect apps and Add-on apps. Each has its own development language requirements:

Connect apps:

Connect apps are designed to connect Business Central with external services or applications. They are often developed using a variety of programming languages, not limited to the AL language, and can be hosted outside of the Business Central environment. Therefore, when a description states that the app is developed using any coding language, it generally refers to a Connect app. This type of app integrates with Business Central through APIs and web services.

Add-on apps:

Add-on apps are built to extend the functionality of Business Central within the application itself. These are developed using the AL language, which is the programming language for Business Central, and they are created and managed within the Visual Studio Code environment with the AL Language extension. An Add-on app is typically a Business Central extension that is directly installed into the Business Central environment.

The language and environment used for developing these apps are key differentiators between Connect apps and Add-on apps.

When developing an app for Microsoft AppSource, it is essential to use an object range that is specifically designated by Microsoft to avoid conflicts with other apps and the base application. The correct object range to use is:

An object range within the range of 70000000 to 74999999 that is requested from Microsoft (D): This range is reserved for AppSource apps. Developers need to request this range from Microsoft to ensure that the objects used in their extension do not conflict with those used by other extensions or by the base application. Using this reserved range helps maintain the integrity and compatibility of extensions published on AppSource.

It's important to note that the other ranges mentioned (A, B, C, and E) are not suitable for apps intended for AppSource. Ranges 50000 to 59999 and 50000 to 99999 are typically reserved for per-tenant customizations or partner solutions, not for distribution on AppSource. The standard range 1 to 49999 is reserved for the base application objects, and using an object range divided by countries (C) is not a standard practice for AppSource apps.

No

No

Yes

No

Explanation

1. The Bug: The issue lies in Line 06: PurchaseLine.SetRange("No.", PurchaseHeader."No.");.

In the Purchase Line table, the field "No." represents the Item Number (or G/L Account number, etc.).

The field that links the line to the Purchase Header is "Document No.".

Because the code filters the Item Number using the Document Number (e.g., searching for an Item named "PO-00001"), it finds no records. IsEmpty() returns true, and the function returns false.

2. Analysis of Options:

Add Clear(PurchaseLine)... (No): The variable PurchaseLine is a local variable declared within the procedure. In AL, local record variables are automatically initialized when the procedure starts. Clearing it manually is redundant and does not fix the logic error.

Add PurchaseLine.SetFilter("Line No.", '>0')... (No): While this is a valid filter to ensure you don't pick up empty lines, it does not solve the problem. The code is already failing because of the incorrect filter on line 06. Adding another filter won't find records that have already been excluded by the wrong "No." filter.

Change the filter on line 06 from "No." to "Document No." (Yes): This is the correct fix. To link a Purchase Line to a Purchase Header, you must join PurchaseHeader."No." to PurchaseLine."Document No.".

Remove "not" in line 07 (No): The logic exit(not PurchaseLine.IsEmpty()); is correct.

If lines exist, IsEmpty() is false. not false is true. (Correct result)

If you remove "not", the function would return true when the order is empty, which is the opposite of what is needed.

You are working on an on-premises Business Central instance and unable to download symbols for a new AL project. The current configuration in launch.json does not allow you to download symbols, and you need to make corrections.

Key Points in the Scenario:

Instance name is TEST.

Developer services port is 7149.

Windows authentication is being used.

Correct Answers:

A. Change the server Instance parameter to TEST.

The serverInstance parameter must match the name of the Business Central instance, which is TEST in this scenario. You need to modify this to reflect the correct instance name.

B. Add the port: 7149 parameter.

Since the developer services are using port 7149, you need to specify this in the launch.json file by adding the port parameter with the value 7149.

Incorrect Options:

C. Change the name parameter to TEST: The name parameter is just a label and does not affect downloading symbols, so changing this won't help.

D. Change the authentication parameter to UserPassword: The authentication method is already set to Windows, which is valid for this scenario. Changing it to UserPassword is unnecessary unless specified by the system.

E. Check which server the instance is installed on and replace http://localhost with the correct IP address: Since the server is on the same machine as Visual Studio Code (as specified), localhost is correct.

 No AL command in User Settings:

The correct solution is to Install the AL Language extension.

This issue arises when the AL Language extension is not installed in Visual Studio Code, which is required to work with AL projects in Business Central.

 Error in the Problems tab:

The correct solution is to Download Symbols.

This error typically occurs when the symbols (metadata for pages, tables, etc.) are not downloaded, and Visual Studio Code cannot resolve the reference to the Customer List page. Downloading symbols should fix the problem.

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】.