MB-820 Questions and Answers

Language table → System layer

Activities Cue table → Base layer

Extension Management codeunit → System layer

Business Unit Card page → Base layer

Application Layers in Business Central:

In Business Central, there are different layers such as Base and System, which represent different levels of the application architecture. Here's a breakdown of where each object is likely to belong based on typical Business Central architecture:

Language Table:This table typically belongs to the System layer, as language and localization features are often part of the foundational aspects of the system.

Activities Cue Table:This would likely be found in the Base layer because it involves business logic that supports user interface elements (like activity cues) specific to the Business Central application.

Extension Management Codeunit:The Extension Management Codeunit likely belongs to the System layer, as it deals with handling extensions, which is closely related to the core system functionality for managing and deploying changes.

Business Unit Card Page:This object would typically be part of the Base layer, as it is a business-specific object that handles the user interface for business unit data, part of the core Business Central application.

To properly apply the No. Series Design Pattern in the OnInsert() trigger, the correct sequence of actions should be as follows:

ContosoSetup.Get();

First, retrieve the Contoso Setup record using the Get method. This ensures that the necessary setup information is available, including the No. Series.

if "No." = '' then begin

Next, check if the No. field is empty. If it is, a new number from the No. Series should be assigned.

NoSeriesManagement.InitSeries(ContosoSetup."Vendor Nos.", "No. Series", 0D, "No.", "No. Series");

Call the InitSeries function to assign a new number from the No. Series. This initializes the No. Series for the Vendor Nos. field.

ContosoSetup.TestField("Vendor Nos.");

Lastly, ensure that the Vendor Nos. field is populated and valid by calling TestField.

Correct Order for Code Segments:

ContosoSetup.Get();

if "No." = '' then begin

NoSeriesManagement.InitSeries(ContosoSetup."Vendor Nos.", "No. Series", 0D, "No.", "No. Series");

ContosoSetup.TestField("Vendor Nos.");

 Direction: Both

 Format: VariableText

You are configuring an XMLport for Business Central with the following requirements:

Specifies import or export on the Request page at runtime.

Formats the data in a non-fixed length CSV format.

XMLport Configuration:

Specifies import or export on the Request page at runtime.The Direction property must be set to Both.

This allows the XMLport to both import and export data depending on user selection during runtime.

Formats the data in a non-fixed length CSV format.The Format property must be set to VariableText.

VariableText is used for delimited text formats like CSV, which do not have a fixed length for fields.

To ensure that the values inserted on the Request page of a Business Central report are saved for the next time the report is run, the SaveValues property (D) should be set to true. This property is available on the Request page of the report and, when set to true, allows the system to remember the values entered by the user, so they do not have to re-enter them each time they run the report. This feature enhances user experience by reducing repetitive data entry and ensuring consistency in report parameters across multiple executions. The other options mentioned, such as setting the Transaction Type property to Update (A) or declaring a Savevalues variable in the OnOpenPage trigger (B), are not directly related to saving user input on a report's Request page.

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.

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.

To meet the XMLport configuration requirements:

Link the child table to its parent: Use the OnAfterGetRecord trigger.

Display a confirmation message after the XMLport runs: Use the OnPostXMLPort trigger.

In Business Central, when you are developing an XMLport for data export, triggers are used to perform actions at different stages of the XMLport's operation:

OnAfterGetRecord Trigger:This trigger fires after a record is retrieved from the database but before it is processed for output in the XMLport. It is the ideal place to link child table records to their parent because you have access to the current record that can be used to set filters or modify data in the child table before it is written to the XML file.

OnPostXMLPort Trigger:This trigger fires after the XMLport has finished processing all records. It is the correct place to display a confirmation message because it ensures that the message will appear after the entire XMLport operation is complete. Here, you can use application-specific functions to show the message, such as MESSAGE function in AL code.

By placing the appropriate triggers in these positions, you can ensure that the XMLport will link the child records to their parent records during the data export process and will notify the user with a confirmation message once the operation is successfully completed.

The task is to identify unwanted incoming web service calls during the last seven days. To do this, we need to look at KQL (Kusto Query Language) queries that would filter out web service calls based on the timestamp (to ensure the calls are within the last seven days) and by certain characteristics that would indicate they are unwanted, such as the wrong type of protocol (SOAP in this case, as Contoso Ltd. plans to dismiss using it).

Looking at the options:

Option A: This query selects all traces where the timestamp is within the last 7 days and where the custom dimension has a value of 'RT0008', and where the category is either 'ODataV4', 'ODataV3', or 'Api'. This query would show all API calls except SOAP, so it does not directly answer the question about unwanted calls.

Option B: This query filters for traces with a timestamp within the last 7 days, where 'RT0008' is present, and specifically looks for the category 'SOAP'. This query is correct because it directly targets SOAP calls, which are the unwanted calls according to Contoso Ltd.'s plans.

Option C: Similar to option B, this query filters for traces within the last 7 days and looks for 'RT0008' but uses the equality operator for the category 'SOAP'. This would also correctly return the unwanted SOAP calls.

Option D: This query also filters for traces within the last 7 days, but it excludes the 'ODataV4' category, which doesn't necessarily target the unwanted SOAP calls.

Option E: This query selects traces where the timestamp is within the last 7 days and the custom dimension has 'RT0008'. However, it filters out categories 'ODataV4' and 'Api', which does not directly help in identifying the unwanted SOAP calls.

Therefore, the queries that should be used to determine if there are unwanted incoming web service calls (SOAP calls) in the tenant during the last seven days are Options B and C. These queries are specific to identifying SOAP protocol usage, which is what Contoso Ltd. considers unwanted.

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】.

For a task that is performed infrequently and requires users to follow a sequence of steps, a wizard-like interface is ideal. In Microsoft Dynamics 365 Business Central, the NavigatePage page type (A) is best suited for this purpose. NavigatePage is designed to guide users through a series of steps or pages, allowing them to complete a task by making choices or entering data in a structured manner. This page type is often used for setup wizards, data migration tasks, or any other process that benefits from a step-by-step approach. Unlike the other page types like Card (B), RoleCenter (C), or List (D), NavigatePage specifically supports the navigation and decision-making flow required for wizard creation, making it the optimal choice for this requirement.

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.

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.

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 the context of Microsoft Dynamics 365 Business Central, an extension may not appear in the tenant for several reasons, particularly after an upgrade to a new major version.

Option A suggests that the extension was published as a DEV extension, which typically would not cause it to disappear after an upgrade because DEV extensions are intended for development and testing within sandbox environments.

Option B indicates that the extension was not compatible with the new version within 60 days of the first notification. This is a likely reason because Microsoft enforces compatibility rules, and extensions that are not made compatible within the specified timeframe might be removed or disabled.

Option C refers to the extension being published as a PTE (Per-Tenant Extension) and mentions the Platform parameter not being updated. This could cause issues, but not specifically the disappearance of the extension after an upgrade.

Option D expands on Option C by adding that both the Platform and Runtime parameters were not updated in the application file. This is a critical aspect because if these parameters are not correctly set to indicate compatibility with the new version of Business Central, the extension could be disabled or removed.

Option E is similar to Option B but mentions a 90-day period. This option does not align with standard Business Central practices for version compatibility requirements.

Therefore, the two possible reasons for the disappearance of the extension in the tenant after an upgrade are that the extension was not compatible with the new version within the required timeframe (Option B) and that the extension was published as a PTE without the Platform and Runtime parameters being updated (Option D).

 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.

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.

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;

}

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;

Read Scale-Out:

Read scale-out is a feature in Business Central that allows you to improve performance by distributing read-only queries (such as the ones from the ticketAPI) across multiple read replicas in the cloud database. This reduces the load on the primary database and helps improve the response time for read-intensive operations, like analyzing POS data through the ticketAPI.

Data Access Intent - ReadOnly:

When enabling read scale-out, you can configure the DataAccessIntent property of APIs to be ReadOnly. This directs the system to use read replicas to handle read-only queries, which enhances performance by offloading such queries from the primary database.

Why Not Other Options?

Option A (ODataReadonlyGetEnabled): This parameter is unrelated to read scale-out and primarily affects OData services behavior, not API performance tuning.

Option B (AccessByPermission): Setting the permission to Read does not directly affect the performance. It only controls access based on user permissions.

Option D (DataAccessIntent ReadOnly): While setting this property to ReadOnly helps in read-only operations, enabling read scale-out (option C) ensures the underlying infrastructure is optimized to handle such read operations, which is the fundamental action required.

Reference Documentation:

Read Scale-Out in Business Central

Data Access Intent in AL

In Business Central, fields in tables are assigned specific data types that determine the kind of data they can store. For the Non-conformity table mentioned in the case study, the following data types should be used:

Date for the Non-Conformity Date field: This is because the Non-conformity Date field is required to store only the date when the non-conformity was recorded. The Date data type is appropriate for storing dates without times.

Code for the Non-Conformity Number field: The Non-conformity Number field is described to use alphanumeric values with a format that includes "NC" and the year, like "NC24-001". In Business Central, the Code data type is used for fields that store alphanumeric keys. It is a text field with a limited length, which makes it suitable for number series that contain letters and numbers.

Other options are not suitable:

A. Integer for the Non-conformity Number field: This would not be appropriate because the Non-conformity Number includes alphanumeric characters and not just integers.

B. DateTime for the Non-Conformity Date field: This is not correct because there is no requirement to store the time alongside the date.

C. Char for the Non-Conformity Number field: Char data type is not typically used in Business Central for number series or identifiers. The Code data type is preferred for this purpose.

https://api.businesscentral.dynamics.com/v2.6/myTenant/myEnvironment/api/alpine/integration/rooms

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

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 Explanation

In 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.