Perform operation at Entity level post all Staging data Insert or Before Target insert starts in D365 FnO

As the title suggests, there are sometimes requirements where we need to perform some operation(s) Just before target data insert operation triggers (or in between the whole DMF cycle) but not at the any datasource event or at the Entity insert method. 

One of such requirement can where the Any Header data to be populated before line insertion. 

Good news is we have a way to achieve it via postGetStagingData method at Entity level, Bad news is it works only after staging is inserted and works even if all target data fails validation.

Below is the implementation way for that 

public class SaddafDemoEntity extends common
{
    /// <summary>
    /// Post staging data
    /// </summary>
    /// <param name = "_dmfDefinitionGroupExecution">DMFDefinitionGroupExecution</param>
    public static void postGetStagingData(DMFDefinitionGroupExecution _dmfDefinitionGroupExecution)
    {
        TestHeaderTable      headerTable;
        SaddafDemoStaging    staging;

        select firstonly staging
            where staging.DefinitionGroup   == _dmfDefinitionGroupExecution.DefinitionGroup
            && staging.ExecutionId          == _dmfDefinitionGroupExecution.ExecutionId;

        headerTable.DMFExecutionId =  staging.ExecutionId; //Just the example, you can use any field needed
        headerTable.insert();

        ttsbegin;
        staging = null;
        update_recordset staging
            setting ParentRefRecId = headerTable.RecId
        where staging.DefinitionGroup   == _dmfDefinitionGroupExecution.DefinitionGroup
        && staging.ExecutionId          == _dmfDefinitionGroupExecution.ExecutionId;

        ttscommit;
    }
}

For Entities using set based operations, we have another method known as preTargetProcessSetbased that can be implemented in similar way as above and is available to use just before Target process initiates (which is obvious by name😃). 

Happy Coding!!!