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

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.

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

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】.

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.

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.

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

 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.

 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.

Instructions to use for Incident Date and Status fields:

The correct instruction is "Incident Date" := Workdate(); "Status" := Status::Open;. This ensures that when a new record is created, the Incident Date is set to the current work date, and the Status field is initialized to 'Open'. This is essential for ensuring that the incident data is always timestamped and correctly marked upon creation.

Trigger to introduce the function:

The correct trigger is Trigger OnModify. This trigger ensures that when a record is modified, such as when an update to the status is made (e.g., from Open to Closed), the necessary logic will be executed to handle the update of fields like Incident Date and Status.

Step-by-Step References:

Workdate Function in AL

Triggers in AL

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.

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.

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.

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.

In Business Central, when creating an entitlement object to enable transactability for AppSource apps and mapping it to a plan in Partner Center, the Type property of the entitlement object should be set to PerUserServicePlan (A). The PerUserServicePlan type is used to define an entitlement that is based on a service plan, which is typically how transactability features are managed for apps distributed through AppSource. This type of entitlement allows for the mapping of specific features or capabilities of the app to a service plan in Partner Center, enabling granular control over what users are entitled to use based on their subscription. The other values, such as Implicit (B), Unlicensed (C), and Role (D), are used in different contexts and do not apply to the scenario of mapping an entitlement object to a plan for AppSource apps.

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.

Using InherentPermissions in an event subscriber with the specified syntax could potentially resolve the permission issues related to MyTable, provided that the permissions specified (in this case, 'R' for Read) align with the minimum necessary for the users to perform their tasks. This approach allows the app to grant permissions dynamically based on the context of the event subscriber, which in this case is involved with inserting data into MyTable. By granting Read permission at the event level, it ensures that users have the necessary permissions to interact with MyTable in the context of the operations facilitated by the event subscriber, without needing to alter existing permission sets or grant broader permissions than necessary. This solution adheres to the principle of least privilege by ensuring that permissions are granted only within the narrow scope needed for specific operations, thereby potentially resolving the reported user issues in a secure and controlled manner.

For the data integrity requirements, the table field properties to use are:

To establish lookups into other records, use the TableRelation property.

To validate if a record exists in a destination record, use the ValidateTableRelation property.

In Business Central, when creating tables to hold data, maintaining data integrity is crucial:

TableRelation Property:This property is used to create a relationship between the field in one table and a field in another table, which is typically used for lookups. When you set the TableRelation property on a field, it allows users to select from a list of values that exist in the related table.

ValidateTableRelation Property:This property is used to ensure that the value entered in a field matches one of the values in a related table. If a user tries to enter a value that doesn't exist in the related table, an error will occur.

For the given requirements, you should configure the following actions:

For child data items not to be displayed on the request page for some master-detail reports, set the DataItemLinkReference property to the parent data item.

To decrease the amount of time to select key filter fields, specify the RequestFilterHeading property.

In Dynamics 365 Business Central, when customizing report request pages, certain properties can be set to control the behavior and display of the report options:

Hiding Child Data Items:The DataItemLinkReference property is used to link a child data item to a parent data item in the data model of a report. Setting this property correctly will ensure that the child data items are related to the correct parent data item and will be displayed or hidden accordingly on the request page. If the goal is to prevent child data items from being displayed, you need to make sure they are correctly linked and configured to not appear.

Optimizing Filter Field Selection:The RequestFilterHeading property is used to group filter fields on the request page. By specifying this property, you can create a more organized and user-friendly interface, which can significantly speed up the process of selecting filters. This property allows you to categorize filters into headings, making it quicker and easier for users to find and set the necessary filters for the report.

By adjusting these properties on the report request page as part of the per tenant extension customization, you will address the company's requirements to optimize the user experience when running reports.