...

examples/basecoin/app/handler.go

@@ -0,0 +1,76 @@
+XXX Rename AppHandler to DefaultAppHandler.
+XXX Register with a sdk.BaseApp instance to create Basecoin.
+XXX Create TxParser in anotehr file.
+
+package app
+
+import (
+	wire "github.com/tendermint/go-wire"
+	"github.com/tendermint/go-wire/data"
+
+	sdk "github.com/cosmos/cosmos-sdk"
+	"github.com/cosmos/cosmos-sdk/store"
+)
+
+// AppHandler has no state for now, a more complex app could store state here
+type AppHandler struct{}
+
+func NewAppHandler() sdk.Handler {
+	return AppHandler{}
+}
+
+// DeliverTx applies the tx
+func (h Handler) DeliverTx(ctx sdk.Context, store store.MultiStore,
+	msg interface{}) (res sdk.DeliverResult, err error) {
+
+	db := store.Get("main").(sdk.KVStore)
+
+	// Here we switch on which implementation of tx we use,
+	// and then take the appropriate action.
+	switch tx := tx.(type) {
+	case SendTx:
+		err = tx.ValidateBasic()
+		if err != nil {
+			break
+		}
+		db.Set(tx.Key, tx.Value)
+		res.Data = tx.Key
+	case RemoveTx:
+		err = tx.ValidateBasic()
+		if err != nil {
+			break
+		}
+		db.Remove(tx.Key)
+		res.Data = tx.Key
+	default:
+		err = errors.ErrInvalidFormat(TxWrapper{}, msg)
+	}
+
+	return
+}
+
+// CheckTx verifies if it is legit and returns info on how
+// to prioritize it in the mempool
+func (h Handler) CheckTx(ctx sdk.Context, store store.MultiStore,
+	msg interface{}) (res sdk.CheckResult, err error) {
+
+	// If we wanted to use the store,
+	// it would look the same (as DeliverTx)
+	// db := store.Get("main").(sdk.KVStore)
+
+	// Make sure it is something valid
+	tx, ok := msg.(Tx)
+	if !ok {
+		return res, errors.ErrInvalidFormat(TxWrapper{}, msg)
+	}
+	err = tx.ValidateBasic()
+	if err != nil {
+		return
+	}
+
+	// Now return the costs (these should have meaning in your app)
+	return sdk.CheckResult{
+		GasAllocated: 50,
+		GasPayment:   10,
+	}
+}