Chain of command or method wrapping in AX D365 a New Feature in Extension (PU 8 onwards)

Hi,

Chain of command or method wrapping in D365 a New Feature in Extension  (PU 8 onwards)

This new powerful extension capability in X++ in AX D365.

This Feature enables to call or use protected members and methods without making them hookable or using pre or post event handlers. 

Sample Chain of command

Standard PriceDiscAdmTrans Table's ValidateWrite() method

public class PriceDiscAdmTrans extends common
{

  public boolean validateWrite()
    {
//Standard Validations
    }
}
}

Same Standard method can be accessable at Extension Class using NEXT Keyword

[ExtensionOf(tableStr(PriceDiscAdmTrans))]
public final class MyPriceDiscAdmTrans_Extension
{
 public boolean validateWrite()
    {
            boolean ret;
            ret= next validateWrite(); // This will call Standard method validations then runs below extension code

            if (!this.FromDate)
                ret = checkfailed("From date must be filled");

            return ret;

    }
}

https://www.arbelatech.com/insights/blog/dynamics-365-finance-operations-chain-of-command-new-features.html

https://blogs.msdn.microsoft.com/mfp/2017/07/04/extensible-x-chain-of-command/

https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/extensibility/method-wrapping-coc

http://www.dynamicon.de/en/2017/07/15/chain-of-commands-x-von-dynamics-365-for-finance-and-operations/

https://community.dynamics.com/ax/b/vishalsblogonmsdynamicsax/archive/2017/07/18/dynamics-365-for-operations-class-extensions-and-chain-of-command-coc-next-keyword

You need to pass extra information from your code to an existing method and act on it in a pre/post handler and You need to pass extra information from your code to a method on a class that is called via other method(s) on the class. Check below post.

https://blogs.msdn.microsoft.com/mfp/2017/08/31/extensible-x-method-signatures/