Add event aggregator function call in baseapp (#268)

* Add event aggregator function call in baseapp

* fix comments

* remove unneeded line addition

* update aggregator and return

* remove returning of error

* add change log entry

CHANGELOG.md

@@ -39,7 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## Unreleased
 
-* nothing
+* (baseapp) Add a optional function to baseapp to manipulate events [\#1092](https://github.com/provenance-io/provenance/issues/1092)
 
 ---
 

baseapp/baseapp.go

@@ -136,6 +136,8 @@ type BaseApp struct { // nolint: maligned
 	abciListeners []ABCIListener
 
 	feeHandler sdk.FeeHandler
+
+	aggregateEventsFunc func(anteEvents []abci.Event, resultEvents []abci.Event) ([]abci.Event, []abci.Event)
 }
 
 // NewBaseApp returns a reference to an initialized BaseApp. It accepts a
@@ -734,17 +736,31 @@ func (app *BaseApp) runTx(mode runTxMode, txBytes []byte) (gInfo sdk.GasInfo, re
 				// append the events in the order of occurrence
 				result.Events = append(anteEvents, result.Events...)
 			}
-			// additional fee events
-			if len(feeEvents) > 0 {
-				// append the fee events at the end of the other events, since they get charged at the end of the Tx
-				result.Events = append(result.Events, feeEvents.ToABCIEvents()...)
-			}
 		}
+		// additional fee events
+		if len(feeEvents) > 0 {
+			// append the fee events at the end of the other events, since they get charged at the end of the Tx
+			result.Events = append(result.Events, feeEvents.ToABCIEvents()...)
+		}
+	}
+
+	if result != nil { // tx was successful run aggregator for ante and result events
+		anteEvents, result.Events = AggregateEvents(app, anteEvents, result.Events)
+	} else { // tx failed run aggregator for ante events only since result object is nil
+		anteEvents, _ = AggregateEvents(app, anteEvents, nil)
 	}
 
 	return gInfo, result, anteEvents, priority, ctx, err
 }
 
+// AggregateEvents aggregation logic of result events (ante and postHander events) with feeEvents
+func AggregateEvents(app *BaseApp, anteEvents []abci.Event, resultEvents []abci.Event) ([]abci.Event, []abci.Event) {
+	if app.aggregateEventsFunc != nil {
+		return app.aggregateEventsFunc(anteEvents, resultEvents)
+	}
+	return anteEvents, resultEvents
+}
+
 // FeeInvoke apply fee logic and append events
 func FeeInvoke(mode runTxMode, app *BaseApp, runMsgCtx sdk.Context) (sdk.Events, error) {
 	if app.feeHandler != nil {

baseapp/options.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 
+	abci "github.com/tendermint/tendermint/abci/types"
 	dbm "github.com/tendermint/tm-db"
 
 	"github.com/cosmos/cosmos-sdk/codec/types"
@@ -247,3 +248,12 @@ func (app *BaseApp) SetFeeHandler(feeHandler sdk.FeeHandler) {
 
 	app.feeHandler = feeHandler
 }
+
+// SetAggregateEventsFunc sets the function that aggregates events from baseapp result events and feehandler events
+func (app *BaseApp) SetAggregateEventsFunc(aggregateEventsFunc func(resultEvents []abci.Event, feeEvents []abci.Event) ([]abci.Event, []abci.Event)) {
+	if app.sealed {
+		panic("SetAggregateEventsFunc() on sealed BaseApp")
+	}
+
+	app.aggregateEventsFunc = aggregateEventsFunc
+}