Sample Code

OnCustomEvaluateConditionOnTable

[EventSubscriber(ObjectType::Codeunit, Codeunit::"Workflow Condition Eval. BTR", OnCustomEvaluateConditionOnTable, '', false, false)]
local procedure OnCustomEvaluateConditionOnTable(_LookupRecRef: RecordRef; _RecRef: RecordRef; _TempBlob: Codeunit "Temp Blob"; var _IsHandled: Boolean; var _Result: Boolean)
var
     ItemJnlBatch: Record "Item Journal Batch";
     tempItemJnlLine: Record "Item Journal Line" temporary;
begin

    /// Use to allow custom checks for specific tables or conditions. 
    /// Example: to check if the total amount in a Item Journal Batch is zero.
    case LookupRecRef.Number of
        Database::"Item Journal Batch":
            begin
                LookupRecRef.SetTable(ItemJnlBatch);
                // Custom field added to ItemJournalBatch to use as filter
                amountFilter := ItemJnlBatch.GetFilter("Total Amount (LCY) Filter");
                ItemJnlBatch.SetRange("Total Amount (LCY) Filter");
    
                if ItemJnlBatch.Find() then begin
                    // function to get the total batch amount
                    tempItemJnlLine."Amount (LCY)" := ItemJnlBatch.GetAbsJournalTotalAmount(); 
                    tempItemJnlLine.Insert(false);
                    // apply filter the check if amount satisfies the condition
                    tempItemJnlLine.SetFilter("Amount (LCY)", amountFilter); 
                    exit(not tempItemJnlLine.IsEmpty());
                end;
            end;
    end;
end;

Custom Record Change implementations.

Either update table’s OnModify() trigger or subscribe to OnAfterModifyEvent() in a codeunit and add below call to RunPowerFlowOnModifyEvents(). It is sometimes necessary to add it in places other than the OnModify() or OnAfterModifyEvent() as field validations can trigger a modify at sometimes, undesirable times. 
[EventSubscriber(ObjectType::Table, Database::"SharePoint Attachment BTR", OnAfterModifyEvent, '', false, false)]
local procedure "SPAttachment_OnAfterModifyEvent"(var Rec: Record "SharePoint Attachment BTR"; var xRec: Record "SharePoint Attachment BTR"; RunTrigger: Boolean)
var
    ModificationHandler: Codeunit Braintree.PowerFlow.Monitoring."Modification Handler BTR";
begin
    ModificationHandler.RunPowerFlowOnModifyEvents(Rec, xRec);
end;

Troubleshooting

Common errors

Record type is not supported by this workflow response.

help power sample code | Braintree
This can occur when you have created an approval workflow but have not implemented status management code.

Solution: implemented status management code or you have forgotten to set the PowerFlow Manages Status field to Yes on the Power Workflow Definition.