Скачать или смотреть Chain of Command DataSource validateWrite method wrapper X++ 5 minutes demo

With Dynamics 365 Finance and Operations v7.2 update 9 Microsoft introduced new technology in addition to event handlers, pre/post method handlers and delegates. It is called Method Wrapper and also referred as Chain of Command and it is substantial improvement in advancing extensions coding (versus old style overlayering) You can place you code around (before and after) original method and your "wrapper" doesn't need to be static - it will have access to class instance variables. In the case of DataSource you can address it in your code as this. For example this.cursor() should give you table buffer of the Datasource
Our demo is very short in time. But meanwhile we are showing you all the steps you need to replicate Chain of Command tutorial and replace our custom logic porting with your own. As soon as you read Alternate Key field for the current table record - you know what to do next
At this time DataSource has two methods available for CoC: init and validateWrite and we show you Microsoft URL where you can find information on Chain of Command