Good day everyone!

Today I want to share with you one experience with dynamic (virtual) data in Acumatica.

Imagine that you want to have a custom virtual view in Acumatica, and use it to get and update records in the cache.

It can be a lot of different situations such as getting data from a file and putting it into view or getting data from another view, updating the records and so on.

For example, let take a popular screen Sales Order (SO301000).

On updating the Document Details (SOLine) row, I want to have a custom control Availability of selected Item.

What does it look like in the code?

I created a SOOrderEntryExt graph extension and my virtual DAC:

 Snippet

[PXVirtual]

public class CustomVirtualDAC : IBqlTable
{
 
    #region InventoryID
    public abstract class inventoryID : PX.Data.BQL.BqlInt.Field<inventoryID> { }
 
    [PXInt(IsKey = true)]
    [PXDefault(PersistingCheck = PXPersistingCheck.Nothing)]
    [PXUIField(DisplayName = "InventoryID")]
    public virtual int? InventoryID
    {
        get;
        set;
    }
    #endregion
 
    #region SiteID
    public abstract class siteID : PX.Data.BQL.BqlInt.Field<siteID> { }
 
    [PXInt(IsKey = true)]
    [PXDefault(PersistingCheck = PXPersistingCheck.Nothing)]
    [PXUIField(DisplayName = "SiteID")]
    public virtual int? SiteID
    {
        get;
        set;
    }
    #endregion
 
    #region LocationID
    public abstract class locationID : PX.Data.BQL.BqlInt.Field<locationID> { }
    [PXInt(IsKey = true)]
    [PXDefault(PersistingCheck = PXPersistingCheck.Nothing)]
    [PXUIField(DisplayName = "LocationID")]
    public virtual int? LocationID
    {
        get;
        set;
    }
    #endregion
 
    #region AvailQty
    public abstract class availQty : PX.Data.BQL.BqlDecimal.Field<availQty> { }
    [PXDecimal(2)]
    [PXDefault(PersistingCheck = PXPersistingCheck.Nothing)]
    [PXUIField(DisplayName = "AvailQty")]
    public virtual decimal? AvailQty { get; set; }
    #endregion
}

 After in SOOrderEntryExt I added my view and event:

public SelectFrom<CustomVirtualDAC>.View CustomVirtualView;
 
public virtual void _(Events.RowUpdated<SOLine> e)
{
    SOLine oldRow = e.OldRow as SOLine;
    SOLine row = e.Row as SOLine;
    CustomVirtualDAC currVirtualRez = null;
 
    if (row != null)
    {
        currVirtualRez = ReturnVirtualDACRez(row.InventoryID,
            row.SiteID, row.LocationID);
 
        if (row.OrderQty > oldRow.OrderQty)
        {
            //do what needed
            currVirtualRez.AvailQty -= row.OrderQty - oldRow.OrderQty;
            CustomVirtualView.Update(currVirtualRez);
        }
    }
 
}

 And one more method where I can return the needed row or add if it does not exists:

public CustomVirtualDAC ReturnVirtualDACRez(int? inventoryID, int? siteID, int? locationID)
{
    CustomVirtualDAC currVirtualRez = null;
 
    foreach (CustomVirtualDAC mkinItemStatus in
        CustomVirtualView.Select())
    {
        if (mkinItemStatus.InventoryID == inventoryID && mkinItemStatus.SiteID == siteID && mkinItemStatus.LocationID == locationID)
        {
            currVirtualRez = mkinItemStatus;
        }
    }
 
    if (currVirtualRez == null)
    {
 
        InventorySummaryEnq tempGraph = PXGraph.CreateInstance<InventorySummaryEnq>();
        tempGraph.Filter.Current.InventoryID = inventoryID;
        tempGraph.Filter.Current.SiteID = siteID;
        tempGraph.Filter.Cache.Update(tempGraph.Filter.Current);
        foreach (InventorySummaryEnquiryResult record in tempGraph.ISERecords.Select())
        {
            CustomVirtualDAC newVirtualRez = new CustomVirtualDAC();
 
            newVirtualRez.InventoryID = record.InventoryID;
            newVirtualRez.SiteID = record?.SiteID;
            newVirtualRez.LocationID = record?.LocationID;
            newVirtualRez.AvailQty = record?.QtyAvail;
 
            CustomVirtualView.Insert(newVirtualRez);
        }
 
    }
 
    return currVirtualRez;
}

Everything seems ready and should work.But not. I receive error message Incorrect syntax near the keyword 'OPTION':

This is because Aсumatiсa is still trying to extract data from a table that does not exist. And none of the attributes such as [PXCopyPasteHiddenView] or [PXVirtualDAC] does not help.

To resolve this problem, you must implement a Dataview delegate when using a Virtual DAC.

So, in your graph extension you must add a dataview delegate to return the records that you need:

protected virtual IEnumerable AvailibilityView()

      {

       //fetch your records

         return your records;

      }

In my specific case, I must implement something like that:

public virtual IEnumerable customVirtualView()
{
    List<CustomVirtualDAC> listRez = new List<CustomVirtualDAC>();
 
    foreach (CustomVirtualDAC line in CustomVirtualView.Cache.Inserted)
    {
        listRez.Add(line);
    }
 
    foreach (CustomVirtualDAC line in CustomVirtualView.Cache.Updated)
    {
        listRez.Add(line);
    }
    return listRez;
}

 Because I can`t call CustomVirtualView.Select() in the delegate because this will loop the code.

Now it will work.

Summary

In case if you need to read data from some 3-rd party source, and display it on the screen, then you have two ways:

1. Create useless table in Acumatica data base

2. Follow technique described in this article.