Seeking advice on creating a "Lockout" utility for processes performed by my application

Hi @Leonardo Justiniano 

Good question.  This merge program makes updates to over 100 tables potentially depending on which modules you are using.  It updates customer history statistics for instance.  If you are in the middle of a merge and someone posts an invoice to a customer that is being removed (merged into another customer), the “FROM” customer may be  removed from the system during the time that invoice is being posted.  When the other users transaction attempts to post, it may fail because by the time that transaction is posting, the customer may be in a deleted status.

The merge tools I am creating are not for casual use.  They should only be used by a user (Admin) who has authority to make very pervasive changes to the system and all precautions should be taken to prevent possible data corruption.  All merges are wrapped in a transaction so if something goes wrong, the merge will fail with no negative impact.  But it needs to be performed in isolation.   

It may not seem obvious, but merging customers or vendors requires changes to tables that the Acumatica framework does not allow such as changing the value of a key field in a DAC.  Acumatica will not let you change the customer ID (BAccountID) on an ARTran record for example.  You would have to delete the original and create a new one which may change the history of who created the record and a whole host of other implications.  That is just a simple example.  I’ve worked for months on this application developing and testing exhaustively.  So, I am really aware of what can happen if it is not used cautiously.  Hence, only use it when nobody else can.  :-)  Even merging customers on one tab and vendors on another tab can cause errors because many of the same tables are updated for both.  You might not think that a shipping table will have customers and vendors in it, but there are a ton of crossovers in location id’s etc.

If anyone wants to know why Acumatica doesn’t yet provide the ability to merge customers or vendors, I think I would consider myself an expert as to why they don’t.  😉

Thanks for the comment though.  I can always count on you for support and great advice.  You saved my bacon on the modifying the customer number description display value on the customer lookup field!

Thanks!

Joe

I was asked to provide my solution.  Hope you like it! 😊

I created a “setup” table to hold one record showing which module is currently processing merges.  It only has two fields, CompanyID and Module.

	#region ICSMergeLock
	[Serializable]
	[PXCacheName("ICSMergeLock")]
	public class ICSMergeLock : IBqlTable
	{
		#region Module
		[PXDBString(2, IsFixed = true)]
		[PXDefault(MergeType.MergeTypeAvailable)]
		public virtual string Module { get; set; }
		public abstract class module : PX.Data.BQL.BqlInt.Field<module> { }
		#endregion
	}
	#endregion

On the graph, I use a field in the Filter to show the value from the ICSMergeLock table.  If it is available, the process buttons are enabled.  I also created a LockoutStatus field to show if the site is locked out.  If the site is not locked out, the process buttons are disabled.

These are the field on the graph Filter

			#region MergeAvailability
			[PXString(2, IsFixed = true)]
			[PXUIField(DisplayName = "Processor Availability", Enabled = false)]
			[MergeAvailability]
			public virtual string MergeAvailability { get; set; }
			public abstract class mergeAvailability : 
               PX.Data.BQL.BqlString.Field<mergeAvailability> { }
			#endregion

			#region LockoutStatus
			[PXString(2, IsFixed = true)]
			[PXUIField(DisplayName = "Lockout Status", Enabled = false)]
			[LockoutStatus]
			public virtual string LockoutStatus { get; set; }
			public abstract class lockoutStatus : 
               PX.Data.BQL.BqlString.Field<lockoutStatus> 
            { }
			#endregion

When a user opens a merge processor, say the Customer merge processor, the Lockout status and Merge status fields are checked and the buttons are enabled/disabled accordingly.

This is the custom attribute applled to the LockoutStatus and MergeAvailability fields.  They are disabled dropdown lists on the form.

	public class LockoutStatusAttribute : PXStringListAttribute
	{
		public LockoutStatusAttribute() : base(
		new string[]
		{
					LockoutStatus.NotLockedOut,
					LockoutStatus.LockedOut
		},
		new string[]
		{
					ICSMessages.UsersNotLockedOut,
					ICSMessages.UsersLockedOut
		})
		{ }
	}

	public class MergeAvailabilityAttribute : PXStringListAttribute
	{
		public MergeAvailabilityAttribute() : base(
		new string[]
		{
					MergeType.MergeTypeAvailable,
					MergeType.MergeTypeCustomer,
					MergeType.MergeTypeVendor
		},
		new string[]
		{
					ICSMessages.MergingAvailable,
					ICSMessages.CurrentlyMergingCustomers,
					ICSMessages.CurrentlyMergingVendors
		})
		{ }
	}

I did this part in the RowSelected of the Filter.  I know I am not supposed to do updates in the RowSelected, but there are only a couple hits to that method so it won’t impact performance.  I honestly don’t know where else I could do it.

		protected void _(Events.RowSelected<RecordsToProcessFilter> e)
		{
			bool showButton = true;
			RecordsToProcessFilter row = e.Row;
			if (row == null) return;

			UPLock locked = LockedOut.Select();

			if (locked == null)
			{
				showButton = false;
			}

			ICSMergeLock mergeLocked = MergeLockStatus.Select();

			if (mergeLocked == null)
			{
				var setupGraph = PXGraph.CreateInstance<ICSMergeLockSetup>();
				ICSMergeLock newRow = new ICSMergeLock();
				newRow.Module = MergeType.MergeTypeAvailable;
				// Acuminator disable once PX1044 ChangesInPXCacheInEventHandlers [this can only fire one time. Ever.]
				setupGraph.Setup.Insert(newRow);
				// Acuminator disable once PX1043 SavingChangesInEventHandlers [this can only fire one time. Ever.]
				setupGraph.Actions.PressSave();
				setupGraph.Clear();
			}

			mergeLocked = MergeLockStatus.Select();

			if (mergeLocked.Module != MergeType.MergeTypeCustomer && mergeLocked.Module != MergeType.MergeTypeAvailable) showButton = false;

			if (Filter.Current != null)
			{
				Filter.Current.MergeAvailability = mergeLocked.Module;
				if (locked == null)
				{
					Filter.Current.LockoutStatus = ICSMergeTools.Helper.LockoutStatus.NotLockedOut;
				}
				else
				{
					Filter.Current.LockoutStatus = ICSMergeTools.Helper.LockoutStatus.LockedOut;
				}
			}

			CustomersToMerge.SetProcessAllEnabled(showButton);
			CustomersToMerge.SetProcessEnabled(showButton);
		}

Where I check if mergeLocked == null, the record is added to the ICSMergeLock table.  I didn’t want to use a DB script to prepopulate this field when the project is published because I have no way of knowing what the CompanyID is for the tenant.  That code will only fire one time (ever).

In the event that one processor does not close out gracefully I added a PXButton on the screen to allow the user to manually reset the merge availability status.  The screen looks like this:

When the Process button is clicked, the ICSMergeLock table is updated to indicate which merge processor is active.  At the end of the process, it resets that field back to available.

If anyone wants any more details or clarification, just let me know.