Tuesday, January 29, 2019

MSDYN365BC - Futuristic CAL Development - Customize Base Code 1.

Hi Readers,

As discussed in the Last article, in this post we will continue with our Customer Requirements.

If you are new to this series then Please Refer Table of Index.

In this article, we will discuss about adding custom code in base objects and what is the Futuristic way of adding code.  In your customer are Pre-2018 then you can use Hooks for those instances.

Let's add the actions in Page Chart of Accounts as shown below.

And similar action in G/L Account Card as shown below.

Now the Next part of customer requirements is to populate Expense Code in Purchase order Page when a G/L Account is selected. For that let's add the field Expense code in Purchase Line Table and Purchase order Subform, as shown below.

Or so last part of customer requirements that we will discuss in this article to have written that custom code which will pull "Expense Code" from G/L Account Card and populate it in Purchase Line.

As all we are C/AL Experts, let's see in Table 39 what happens when user key in the number Field.

  • OnValidate Trigger on No. field has a case Statement which calls different functions based on Type. We are only concerned about CopyFromGLAccount.

  • If we move that function CopyFromGLAccount we will see the last line in Function which says "OnAfterAssignGLAccountValues(Rec,GLAcc)"

  • If we navigate to that function, its a diffrent which which have no code and Function starts with the word [IntegrationEvent]

What we see in Line No. - 4793 above is an Integration Event that we will subscribe for our custom code.

What we would have done in Old C/AL Way?
We would have added one single line of code in CopyFromGLAccount function, which will look something like - "Expense Code" := GLAcc."Expense Code";

How to Do that in Future?

  1. Create a New Codeunit. I am creating codeunit 50000.
  2. Next, I will create a function in Codeunit called "TransferExpenseCodeToPurchLineFromGL"
  3. Next is we will set the following properties - 
    1. Event - Subscriber.
    2. EventPublisherObject - Table 39.
    3. & EventFunction.

If you lookup EventFunction - You will same Integration Event available that we see in the last step.

Click ok to Next message and We will see that few parameters are added in function and Subscriber is added in the function Name.

If we look function closely - Purchase Line variable is passed as Reference so we will be able to plug our code easily as above.

To understand How Execution will occur is like this - 

When System Executes Code in Purchase Line and Code will reach to line No. 2652 and then execution will move to custom Codeunit and then will come back in Table 39.

  • Purchase Line    - Line No. 2652.
  • Codeunit 50000 - Line No. 2653. (actual line No. 6)
  • Codeunit 50000 - Line No. 2654. (actual line No. 7)
  • Codeunit 50000 - Line No. 2655. (actual line No. 8)

In Next article, we will discuss - 

  • What we did in this article? 
  • what is Integration Event? 
  • Who can write it and how it executes?

Hope it makes sense, Stay Tuned for More!. Add your views as the comment to this article.

Saurav Dhyani


  1. Hi Saurabh,If we have more then one Subscriber functions for the same EventFunction then what is the execution priority? I mean sequence of Subscriber functions.

    1. @Madhu, As per Microsoft there is no defined execution priority. If you test it then its based on Codeunit ID and then the Function position in the codeunit.

  2. Dear Dhyani,Thanks for the information.