Few things that can save you a lot of hassle in Per Tenant Extension Code Upgrade in Microsoft Dynamics 365 Business Central Wave 2 (version 15) Upgrade

Problem Statement:

With a change in Business Central Version from Version 14 to Version 15, I had noticed a few things got deprecated. Instead, these functions where deprecated and overloaded which why function definition remains the same but the parameters change.

Introduction:

In this blog, let us discuss the changes in Business Central BaseApp coding that can possibly break your extension and prevent you from upgrading. 

Also, I will be discussing the list data type introduced since the 2019 Wave 2 release.

Pre-requisites:

Microsoft Dynamics Business Central Version 14
Microsoft Dynamics Business Central Version 15

Books & References:

List DataType
https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/methods-auto/list/list-data-type

https://www.kauffmann.nl/2019/10/11/net-types-in-al-are-reference-types/

https://demiliani.com/2019/09/17/dynamics-365-bc-wave-2-release-what-happens-now/

Demonstration:

In this blog, let us take an emailing codeunit as a use-case.

1. Change in Variable Declaration:
Earlier in Emailing functionality, we made use of Text to store the Email. For multiple emails, we would append a  SEMICOLON ';' after each recipient.

Text Variable Declaration

Now, Text is replaced by List of Text and we don't need to add SEMICOLON ';' in between

List of Text  variable declaration

2. Change in Codes and functions:
 With respect to the SMTP Mail codeunit, the function is deprecated and overloaded with another function. Also, the deprecated function uses the newly created function

Change in functions

3. Fixing the code:

After the change of the standard codeunit, your functionality code also requires change so that even if the function in support right now but it can be deprecated pretty soon and that your upgrade process should be smooth.

Errors in Version 14 Extension Code

The fix for this is as below.

Old Email Appending Code replaced with ListVariable.Add() function

Change in function parameters

4. List DataType:
List Data Type is pretty straightforward in terms of usage.
You can refer https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/methods-auto/list/list-data-type

The illustrated examples can help you understand the functionality pretty easily.

Just to add, I have copied the syntax from https://www.kauffmann.nl/2019/10/11/net-types-in-al-are-reference-types/
you can add and retrieve data using Get() and Set() methods.

Also, could this mean that Lists are replacing arrays in the near future??
Let me know your comments.

5. TempBlob is marked for removal:
A simple solution is to replace TempBlob record with TempBlob codeunit.
Basically, all the functions inside TempBlob tables will be copied in TempBlob Codeunit.
Refer https://demiliani.com/2019/09/17/dynamics-365-bc-wave-2-release-what-happens-now/

6. Deploying the app:
In order to deploy your app to version 15, you will need to change the app.json file and deploy as the next major version.

Refer Dmitry Katson's blog https://community.dynamics.com/nav/b/katsonsnavblog/posts/how-to-prepare-your-per-tenant-extension-for-the-business-central-wave-2-update

Conclusion:

In this blog, I have attempted to give a glimpse of what I had to change in order to prevent my package from breaking in Business Central version 15 Upgrade.

Also, if I find a few more changes that can break your code I will post it in continuation of this blog.

In the upcoming blogs, I'm planning to write about the new DataTypes that have been added to Microsoft Dynamics Business Central since 2019  Wave 2 Version 15.

Hope this helps :)