MB-820 Microsoft Dynamics 365 Business Central Developer Questions and Answers

For the Install codeunit required for the extension used for installing or updating the Housekeeping app, you should use the following data type and declaration:

Data type for information: ModuleInfo

Start of the declaration of the method or procedure to perform the tasks: local procedure

In AL language, which is used for developing extensions in Business Central, an Install codeunit is a special type of codeunit that is used to handle installation or upgrade logic for an extension.

ModuleInfo is a data type that contains information about the current extension, such as its version. It is typically used within the OnInstallAppPerCompany or OnUpgradePerCompany triggers of an Install codeunit to determine if the app is being installed for the first time or upgraded.

A local procedure within an Install codeunit is a method that is only accessible within the codeunit itself. It is not visible to other objects or extensions. This is suitable for tasks that are internal to the installation process and should not be exposed globally.

These selections align with the requirements of handling installation and update procedures in a controlled and encapsulated manner within Business Central extensions.

 Design pattern for the setup table:

The correct selection here is Adapter. The Adapter design pattern is commonly used when you need to handle integration points or create a setup table that acts as an intermediary for data manipulation, which fits the requirement for the configuration of the non-conformity functionality.

 Data type of the primary key field:

The correct data type is Code. In Business Central, when creating a table with a primary key field, the Code data type is typically used for fields such as document numbers, codes, and identifiers. For a setup table, a Code field is appropriate for keys like "No." series or setup identifiers.

 Property required to prevent users from adding records:

The correct property is InitValue. This property is used to set initial values for fields and can be configured in such a way that users are prevented from adding records directly, typically enforcing control over record creation and editing in configuration scenarios.

Table Structure in Business Central: When creating entities such as "non-conformity" entities in Business Central, you use document tables to represent entities that have a header and line structure. In this case, the non-conformity entity has:

A header with common information (Non-conformity Number, Date, Vendor No., etc.).

One or more lines representing the detailed information for each non-conforming item.

Document Table Usage:

Document Table: A document table is the correct table type for scenarios where you have a header (with general information like vendor details) and lines (with detailed, item-specific information).

Document tables are typically used for entities such as Sales Orders, Purchase Orders, or any other transactional data where you have both header and line information.

Supplemental Table (Option C):

Supplemental tables are usually used to add supplementary information to existing data in Business Central. In this case, we need to store detailed line information, which is a core part of the entity rather than supplementary data, so a supplemental table would not be appropriate here.

Document History Table (Option A):

Document history tables are used to track changes and historical data for entities but are not suitable for the main introduction of the entity and its lines. This option is also not appropriate.

Reference Documentation:

Introduction to Business Central Tables

Document Tables in Business Central

To round up a decimal variable to four decimal places in Microsoft Dynamics 365 Business Central, you should use the Round function with specific parameters. The correct formula is Result := Round(AmountLCY, 0.0001, '=') (B). This function rounds the AmountLCY variable to the nearest value based on the second parameter, which is 0.0001 in this case, representing four decimal places. The third parameter, '=', specifies that the function should round to the nearest value, which effectively rounds up the value when it's halfway between two possible rounded values. This approach ensures that the AmountLCY variable is accurately rounded to four decimal places, which is essential for financial calculations and reporting to maintain precision.

he code in the image shows an event subscription to substitute reports in Business Central.

Code Explanation:

EventSubscriber subscribes to an event in Business Central that allows you to replace or substitute the report at runtime.

The event here is associated with Report Distribution Management.

The local procedure OnSubstituteReport checks if the report being requested is Vendor - List. If it is, it replaces it with My Customized Vendor - List.

Completion:

EventSubscriber ObjectType: The correct object type in this case is Report Distribution Management.

Event Name: The appropriate event to substitute a report is OnAfterSubstituteReport.

Based on the PowerShell script snippet you've provided and the scenario described, you need to configure Docker sandbox environments for a company with specific requirements for Test Toolkit installations.

For SandboxA, since it is configured without the Test Toolkit installed, you would typically use the PowerShell cmdlet Install-TestToolkitToBcContainer to install the Test Toolkit into the Business Central Docker container.

For SandboxB, which must be configured from scratch with the Test Toolkit installed during configuration, you would include the Test Toolkit as part of the New-BcContainer script block that creates the container.

The relevant cmdlets and parameters for SandboxB would include:

-includeTestToolkit: This parameter ensures that the Test Toolkit is included during the creation of the new container.

Given the limited context from the image, here's how you should complete the cmdlets for SandboxB:

Add -includeTestToolkit in the New-BcContainer script to ensure the Test Toolkit is installed when creating SandboxB.

Since you are setting up SandboxB from scratch, you don't need to run Install-TestToolkitToBcContainer separately as the toolkit will be included at the time of container creation with the -includeTestToolkit parameter.

For the New-BcContainer cmdlet, you would fill in the placeholders with the appropriate values for artifactUrl, imageName, and licenseFile if they are required for your specific setup.

Assigning a SUPER permission set to all users would indeed resolve the permission errors and access issues reported by the users, as it grants full permissions across all objects and data in Business Central. However, this approach contradicts the principle of least privilege, which advocates for providing only the minimum levels of access necessary for users to perform their jobs. The SUPER permission set would excessively elevate user privileges, potentially leading to security risks and unintended modifications to critical data. Therefore, while assigning the SUPER permission set might technically resolve the immediate issues, it does not meet the goal of adhering to the principle of least privilege and is not a recommended solution.

You are customizing Business Central using Visual Studio Code and JSON files for configuration.

You plan to:

Open page 21 after publishing.

Enable debugging.

Disable the capability to download the source code.

Which configurations should you add?

The options involve two primary JSON files: launch.json and app.json, and configuration tags like startupObjectId and resourceExposurePolicy.

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.

For the requirements provided, the appropriate page types should be selected as follows:

Display relevant insights in the Housekeeping Role Center: HeadlinePart

Display the additional information for the Room table: FactBox

Configure the first installation: StandardDialog

Comprehensive Detailed ExplanationIn the context of Microsoft Dynamics 365 Business Central, page types are crucial for determining how information is presented to the user.

HeadlinePart: This page type is designed to display key data and insights in a concise and visually appealing manner, often used in Role Centers to highlight important information. It is suitable for the Housekeeping Role Center to display relevant insights.

FactBox: This page type is used to display supplementary information related to a selected record in the main part of the page. It's often used to show additional details about a record in a list, card, or document page. In this scenario, it is suitable for showing additional information about a specific Room when viewing the Room table.

StandardDialog: This is a page type that provides a modal dialog for user interaction, commonly used for setup wizards, confirmations, and input forms that require user action before proceeding. This is appropriate for configuring the first installation, where a step-by-step guided interaction is necessary.

var

TempBlob: Codeunit "Temp Blob";

IncidentOutStream: OutStream;

IncidentInStream: InStream;

ImageFilter, FileName: Text;

begin

// Initialize the TempBlob and streams

TempBlob.CreateOutStream(IncidentOutStream);

Rec.Image.ExportStream(IncidentOutStream); // 'Rec' refers to the current Room Incident record

TempBlob.CreateInStream(IncidentInStream);

// Set the filters and filename for the image

ImageFilter := 'Image Files (*.bmp,*.jpg,*.jpeg,*.gif)|*.bmp;*.jpg;*.jpeg;*.gif';

FileName := 'Customer Picture';

// Prompt the user to download the image

if not DownloadFromStream(IncidentInStream, '', 'Download Incident Picture', '', ImageFilter, FileName) then

Error('Unable to download the image.');

end;

codeunit 52102 "POS API Management"

{

Access = Public;

Permissions = TableData "POS Information" = rwdx;

trigger OnRun()

begin

readAPI();

end;

procedure readAPI()

begin

// Your code here to read from the POS API

end;

}

API Publishing for Extensions:

In Business Central, when creating custom APIs like RoomsAPI, it is important to ensure that they are automatically published during the installation or upgrade of the extension.

To achieve this, you can include a codeunit of type Install in the extension that explicitly publishes the custom API (RoomsAPI) as a web service. This ensures that it is available for use immediately after the extension is deployed without requiring manual intervention.

Codeunit Type:

A codeunit of type Install runs when the extension is installed or upgraded. This type of codeunit can be used to perform setup tasks such as publishing web services or APIs like RoomsAPI.

Why Not Other Options?

Option A (default API configuration): This would not automatically publish the RoomsAPI. Default APIs do not cover custom APIs.

Option B (enable APIs for the environment): Enabling APIs in Business Central allows the standard APIs to be used, but custom APIs still need to be manually published.

Option C (publish via Web Services page): This would work but requires manual intervention to publish RoomsAPI, which does not fulfill the requirement of automatic publishing during installation.

Reference Documentation:

Publishing APIs in Extensions

Codeunit Types in Business Central

To assign the indirect permissions for the Boxes table to the codeunit, use the following code blocks in sequence:

TableData

"Boxes" =

Permissions

RIM

Assigning permissions:In Business Central, to assign permissions within a codeunit, you need to specify the table that the permissions apply to, followed by the type of permission. The sequence starts by indicating that we are defining table data permissions (TableData). Then, we specify the table in question ("Boxes" =). After that, we state that we are setting permissions (Permissions). Finally, we assign the RIM permissions, which stands for Read, Insert, and Modify permissions. The Indirect permission allows the codeunit to read, insert, and modify records in the Boxes table indirectly, meaning these operations can be performed by the codeunit when it is called by a user who has direct permissions for these operations.

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】.

In the context provided by the case study, when calling an API action from a mobile application, the correct format for a POST request to an action in Business Central typically involves specifying the entity (/issues), the ID of the entity (88122e0e-5796-ec11-bb87-000d3a392eb5), and the action to be called (/Copy). The action name should match the exact name as defined in the AL code, which is case-sensitive.

Option A is incorrect because it uses a non-standard format for the action call.

Option B uses the PATCH method, which is generally used for update operations, not for calling actions.

Option C is correct as it uses the POST method, which is appropriate for calling actions, and correctly specifies the entity, ID, and action name.

Option D is incorrect because the action name /copy is in lowercase, while AL is case-sensitive, and it should match the case exactly as defined in the code.

Option E incorrectly adds 'MicrosoftNAV' before the action name, which is not standard for calling actions in Business Central APIs.

Hence, the correct action to use when calling the Issue API action from the mobile application is given in Option C.

In Business Central, when you need to handle the removal of fields and procedures to ensure that other extensions are not affected by these changes, you typically follow a two-step deprecation process. This allows other developers and users to adapt to the changes before they are fully enforced. Here are the steps to handle the removal:

Mark as Obsolete: In the first version where the decision to remove the field or procedure is made, you set the ObsoleteState to Pending and provide an ObsoleteReason. This doesn't remove the feature but indicates to users and developers that it will be removed in the future. This step is crucial for backward compatibility.

Removal: In a subsequent version, after users have had time to adapt to the deprecation warning, you can then remove the field or procedure or set the ObsoleteState to Removed.

Based on these guidelines, here are the three actions you should perform in sequence:

Set the Description field as ObsoleteState = Pending and ObsoleteReason = 'Not in use' in version 2.0.0.0.

Set the Clone procedure as ObsoleteState = Pending and ObsoleteReason = 'Not in use' in version 2.0.0.0.

Remove the Description field from the Issue table in version 2.0.0.1.

These steps will ensure that anyone using the Description field or Clone procedure will receive a warning about the pending deprecation before it is actually removed, thereby minimizing the impact on other extensions and providing a clear path for migration.

When handling the removal of fields and procedures in Microsoft Dynamics 365 Business Central, the process should be carried out in a way that allows other extensions or dependent features to adapt to the changes without causing immediate failures.

Set Obsolete State and Reason for Description Field (Version 2.0.0.0): The first step involves marking the Description field as obsolete by setting the ObsoleteState to 'Pending'. This is a non-breaking change, signaling to other developers and users that the field is planned for removal in a future version. An ObsoleteReason should also be provided to explain why the field is being deprecated.

Set Obsolete State and Reason for Clone Procedure (Version 2.0.0.0): Similarly, the Clone procedure should be marked as obsolete with the ObsoleteState set to 'Pending'. This indicates that the procedure is no longer in use and will be removed in the future. Providing an ObsoleteReason is best practice as it explains the rationale behind the decision.

Remove the Description Field (Version 2.0.0.1): In the subsequent version, after the developers and users have been given time to adapt to the deprecation notice, the Description field can be safely removed from the Issue table. This is considered a breaking change, hence it is done after the field has been marked as obsolete in a previous version.

The reason for not removing the Description field and Clone procedure immediately in version 2.0.0.0 is to avoid causing runtime errors for any extensions or integrations that may depend on these components. By following this sequence, you provide a clear deprecation path that helps maintain the stability of the overall system while evolving the schema.

 Upgrade codeunit trigger: OnValidateUpgradePerDatabase

Since the question specifies that you are handling data upgrades, and you need to use validation before upgrading at the database level, the correct choice is OnValidateUpgradePerDatabase. This method ensures that the upgrade process is validated before applying to the entire database, making it more efficient when data affects multiple companies or structures.

 DataTransfer method to use: CopyRows

CopyRows is the appropriate method when you are handling large data transfers between tables, especially in an upgrade scenario where you are migrating or transferring data from one table to another. It copies entire rows of data and is optimal for bulk data operations during upgrades.

 Verbosity::Critical: This ensures that the telemetry logs the failure as a critical event.

 DataClassification::CustomerContent: This helps classify the error as related to customer data.

 TelemetryScope::All: This ensures that the error is visible across all relevant telemetry scopes, making it easier to monitor the issue in real-time.

To correctly write the code to call the subcontractor's REST API, you would need to set the Authorization header with the base64 encoded username and password for basic authentication. The code segment indicates the use of the Base64Convert codeunit to convert the username and password to base64 format, which is then prefixed with "Basic " to form the proper Authorization header value.

The correct method to add the Authorization header to the RequestHeaders would be:

RequestHeaders.Add('Authorization', 'Basic ' + Base64Convert.ToBase64(Username + ':' + Password));

And the correct method to set the httpContent with the body of the request would be:

httpContent.WriteFrom(Body);

These are the necessary steps to form a well-structured HTTP request for basic authentication and to include the body of the request in the API call.

Code Segment Analysis:

The AL code is trying to read JSON data from a response and process it to extract subcontracting order numbers. It uses JsonToken, JsonObject, and JsonArray to work with the JSON data.

JToken.ReadFrom(Data): This line reads the incoming JSON data and converts it into a token. It processes the full JSON body so you can start working with it.

JToken.SelectToken("results"): This line selects the part of the JSON containing the results array. The key "results" is where the JSON response data is expected to be found.

JsonArray: Once the results are extracted, they are stored as an array, and each element in the array (which is expected to contain subcontracting order numbers) is processed.

SubcontractingOrderNo: The extracted order_no from the JSON is stored in this variable.

Breakdown of Steps:

JToken.ReadFrom(Data): This step reads the entire JSON response.

JToken.SelectToken("results"): This step selects the results array from the JSON response.

JArray.AsArray(): This step converts the selected results token into a JSON array that can be iterated over.

GetValueAsText(JToken, 'order_no'): This step retrieves the order_no from each element in the array.

Correct Code Completion:

JToken.ReadFrom(Data): This is the correct method to read the incoming JSON response, as it will convert the string into a JsonToken that can be further processed.

JToken.SelectToken("results"): This is the correct method to extract the results array from the token. This method looks for the key "results" in the JSON and retrieves the relevant array.

Final Code Segment:

al

Copy code

procedure ReadJsonData(Data: text)

var

JToken: JsonToken;

JObject: JsonObject;

JArray: JsonArray;

SubcontractingOrderNo: Code[20];

begin

if Data = '' then

exit;

JToken := JToken.ReadFrom(Data); // Step 1: Read the JSON response data.

JToken := JToken.SelectToken('results'); // Step 2: Select the "results" array.

JArray := JToken.AsArray(); // Convert the token into a JSON array.

foreach JToken in JArray do begin

SubcontractingOrderNo := GetValueAsText(JToken, 'order_no'); // Retrieve the order number.

end;

end;

JToken.ReadFrom(Data): This reads the raw JSON data string and converts it into a JSON token that can be processed.

JToken.SelectToken("results"): This extracts the results array from the JSON data.

JArray.AsArray(): Converts the token into an array so we can iterate over it.

GetValueAsText(JToken, 'order_no'): Extracts the order_no value from each item in the array.

The correct sequence of actions to configure telemetry for the SaaS tenant and test whether the ingested signals are displayed would be:

Create an Azure Application Insights instance by using the Azure Portal in the Customer's subscription.

Select the environment in the Admin Center and place the connection string in the Application Insights Connection String field.

Select the Application Insights instance, select Logs and then inspect the Traces table.

To set up telemetry for a SaaS tenant using Azure Application Insights, you need to follow these steps:

Create an Azure Application Insights instance: This is the first step where you create an instance in Azure that will collect the telemetry data. This should be done in the customer's Azure subscription because it's their data that you're monitoring.

Configure the SaaS tenant to use the created Application Insights instance: This involves entering the correct connection string in the Business Central Admin Center so that telemetry data from the tenant is sent to the Application Insights instance.

Verify that telemetry is being collected: After configuring, you would check if the telemetry is arriving as expected by inspecting the Traces table in the Azure Application Insights instance. The 'Traces' table holds the telemetry data, which you can query to verify that the correct signals are being ingested.

In Microsoft Dynamics 365 Business Central, when configuring snapshot debugging, it is crucial that the parameters in the configuration file are correctly set. From the options provided, the issue with the debugger not starting correctly is most likely due to an incorrect "userId" parameter.

Option A is the cause of the problem. The "userId" parameter must be the GUID of the user, not the username. The snapshot debugger needs the exact GUID to attach to the right session for debugging.

Option B is incorrect because "breakOnNext" set to "WebClient" is a valid setting. This tells the debugger to break on the next client action in the web client, which is a typical scenario.

Option C is not the cause of the problem. The "userId" parameter is meant to specify which user session to debug, and this works in conjunction with the "breakOnNext" parameter.

Option D is incorrect as the "executionContext" parameter does not need to be set to "Debug" for snapshot debugging to work. "DebugAndProfile" is a valid value for the "executionContext" parameter, as it allows for debugging and collecting performance information.

Therefore, the reason why the debugger does not start correctly is due to Option A: The "userId" parameter must have the GUID of the user specified, not the username.

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.

When exporting a file from a client using the DownloadFromStream method in a Business Central online environment, you need to create an InStream data type to send the data. The solution is to use the CreateInStream method from codeunit "Temp Blob" (A). The Temp Blob codeunit provides temporary storage of BLOBs (Binary Large Objects) and is commonly used for handling files and streams in Business Central. By using the CreateInStream method on a Temp Blob, you create an InStream that can then be used with the DownloadFromStream method to send the file data to the client. This approach is efficient for file handling and transfer in Business Central, especially in scenarios involving data export or file manipulation.

ou plan to call a web service using HttpClient from a Business Central AL extension. The web service must authenticate using a certificate that includes a password, and the password must be hidden during debugging.

Options Explanation:

The question asks for the correct implementation where the certificate and password are provided and where the password is hidden when debugging.

SecretText is a special data type in Business Central that hides sensitive data (like passwords) during debugging.

Specify the value of the post options as Invoice:

Test

Perform calculations and values checking:

Handler

In the context of Microsoft Dynamics 365 Business Central testing, the 'Test' attribute is used to mark a method as a test method. This is where you would specify the action or the behavior you're testing – in this case, setting the post options as Invoice. It's within these test methods that you would simulate setting the posting option to "Invoice" programmatically.

For performing calculations and checking values, you would use 'Handler' methods to handle specific business events or conditions that occur within the system, such as before or after posting a document. These handlers can ensure that calculations are done correctly and that all validation checks pass before the document is posted.

The 'Normal' method would be a standard method that could be involved in the posting process, ensuring that all business logic is correctly applied and that the calculations and value checks are as expected.

In a test codeunit, you would typically have test methods that call these handler and normal methods to verify the business logic in various scenarios, such as posting with different options or checking the results of calculations under different conditions.