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

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;

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

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 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.

KQL Code Segment:

First command (traces):

The query begins with traces to analyze telemetry data logs. The next command determines how the results are filtered or displayed.

take 100: This is the correct option to retrieve the top 100 rows from the traces table.

Command for selecting fields:

project: This command is used to select specific fields from the telemetry data, allowing you to retrieve and display only the fields relevant to the job queue telemetry.

The correct answer is project, as it allows you to choose fields like jobQueueObjectId, jobQueueObjectType, etc., from the customDimensions table.

In the context of cleaning up sandbox environments for a company where data needs to be cleared each time an extension is published, the schemaUpdateMode property in the launch.json file should be set to Recreate (D). Setting this property to Recreate ensures that every time the extension is published, the existing tables and data are dropped, and then the tables are recreated based on the current extension's schema. This mode is particularly useful in development and testing environments where you need a clean slate for testing each version of the extension without the remnants of previous data affecting the outcomes. It's important to use this setting cautiously, as it results in the loss of all existing data in the tables defined by the extension, which is suitable for a sandbox environment but not for production environments.

field(3; "Receipt No."; Code[20])

{

DataClassification = CustomerContent;

TableRelation = "Purch. Rcpt. Header"."No." where ("Buy-from Vendor No." = field("Vendor No."));

}

Field Declaration:

The field(3; "Receipt No."; Code[20]) part defines the field in the table with ID 3 and type Code with a length of 20. This field will hold the receipt number.

DataClassification:

CustomerContent is selected for the DataClassification property, which categorizes the data for privacy and compliance management. This aligns with Business Central's recommendations for handling sensitive data in customer-related tables.

TableRelation Property:

The TableRelation property links the "Receipt No." field to another table, which in this case is the "Purch. Rcpt. Header" table. This ensures that only valid receipt numbers from the Purchase Receipt Header table can be selected or entered in this field.

Relation Filter:

The filter condition is applied using the where clause. It ensures that the Receipt No. is only from the Purchase Receipt Header records where the "Buy-from Vendor No." matches the "Vendor No." of the current record.

The condition field("Vendor No.") is selected from the drop-down as shown in the image. This links the vendor information in the non-conformity table to the receipt in the Purchase Receipt Header table.

By linking the "Vendor No." fields, you ensure that only receipt numbers from the correct vendor are available, which improves data consistency and reduces errors during data entry.

References to AL Language:

The TableRelation property is frequently used to create references between tables in Business Central. In this case, the correct relationship between the "Purch. Rcpt. Header" and the Non-conformity table is established using the TableRelation and filter.

Reference Documentation:

AL TableRelation Property

AL Field Syntax

 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.

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).

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】.

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

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.

 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.

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 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.

 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.

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.

 Add Clear(PurchaseLine); as a line before line 01 of the code: No

 Add PurchaseLine.SetFilter("Line No."; '>0') as a line after line 06: Yes

 Change the filter on line 06 from a "No." field to a "Document No." field: No

 Remove "not" in line 07: No

 Add Clear(PurchaseLine); as a line before line 01 of the code.

No

You do not need to clear the PurchaseLine record before running the query, because the SetRange filters will take care of setting the correct context.

 Add PurchaseLine.SetFilter("Line No."; '>0') as a line after line 06.

Yes

Adding a SetFilter on the "Line No." field ensures that you're checking for actual purchase lines greater than 0, which are valid lines. This would fix the issue where the check might return false even when lines exist.

 Change the filter on line 06 from a "No." field to a "Document No." field.

No

The filter on the No. field is correct, as it's filtering based on the purchase order number. Changing this to Document No. is unnecessary.

 Remove "not" in line 07.

No

The not in line 07 is necessary because IsEmpty() returns true when no lines are found. To correctly return a boolean indicating whether the purchase order has lines, you need to negate the result of IsEmpty().

The report generated by the company contains more Delivery Line records than expected for one specific Delivery Header. To address this, certain properties within the report's data items need to be configured correctly.

Property Configuration Statements:

Configure the DataItemTableView property of the Delivery Header data itemThis property defines the view (filtering and sorting) for a data item in a report. If the DataItemTableView is not configured properly, it might pull in more records than expected.Answer: Yes. By configuring this property, you can control which Delivery Header records are retrieved, preventing excess records.

Configure the RequestFilterFields property of both data itemsThis property allows the user to set fields to filter on the request page of the report. Configuring the filter fields can help users refine the records being retrieved for both Delivery Header and Delivery Line.Answer: Yes. By setting appropriate filters on both data items, users can control which records to include, which is critical in narrowing down the correct data.

Configure the DataItemLink property of the Delivery Line tableThis property links two data items based on common fields. If not configured properly, more Delivery Line records than expected might be retrieved because the link between Delivery Header and Delivery Line might not be accurate.Answer: Yes. Configuring the DataItemLink ensures that only the Delivery Line records associated with the specific Delivery Header are retrieved, avoiding an excess of records.

Conclusion:

DataItemTableView property of Delivery Header data item → Yes

RequestFilterFields property of both data items → Yes

DataItemLink property of Delivery Line table → Yes

Each configuration is necessary for generating the correct number of records in the report dataset.

 XMLport Overview

In Microsoft Dynamics 365 Business Central, XMLports are used for importing and exporting data in XML, CSV, or other text formats. By default, XMLports are designed to work with XML data, but they can also handle delimited text formats like CSV (Comma-Separated Values).

 Requirement Clarification

The requirement is to change the export format from XML to CSV. CSV is a text-based format, not an XML format. To accommodate this, you need to change how the XMLport handles data during export.

 Properties of XMLport

The Format property in XMLports controls whether the output format is XML or a text-based format such as CSV.

The VariableText option of the Format property specifies that the data should be exported in a variable text format, like CSV.

The XMLports default to an XML format, but by setting the Format property to VariableText, you can change the export to CSV format or another text-delimited format.

 Explanation of Correct Answer (E)

To switch from XML to CSV export:

You need to change the Format property of the XMLport to VariableText.

The VariableText option allows for the export of data in a non-XML format, which is precisely what CSV represents (a comma-delimited text file).

 Why Other Options Are Incorrect

Option A (Change the Direction property to Both):The Direction property controls whether the XMLport is used for Import, Export, or Both (import and export), but it does not affect the file format (XML vs. CSV). Hence, this is irrelevant to the file format change.

Option B (Change the FormatEvaluate property to Legacy):The FormatEvaluate property is not related to changing the export format. It deals with the evaluation of the data format during the processing but doesn't change the format type (XML or CSV).

Option C (Change the XmlVeisionNo property to 1.1):The XmlVersionNo property defines the XML version used for the export (such as 1.0 or 1.1). This only applies to XML exports and does not change the format to CSV.

Option D (Fill the FileName property with Items.csv):While this option would specify the name of the file being exported (i.e., "Items.csv"), it doesn't control the format of the export itself. The actual format change is controlled by the Format property.

 Developer Reference from Microsoft Documentation

According to the official Microsoft documentation for XMLports in Business Central, the Format property is critical for determining how data is structured for export. To change the file format from XML to CSV, developers need to set the Format property to VariableText. This allows for export in a text-delimited format, which is ideal for CSV.

XMLport Properties - Format Property

How to: Export Data in Text Format Using XMLports

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.