work on erc20 event_triggered functionality and generic helper for log unpacking and converting. helpers.ConvertToLog and helpers.createTopics have been adjusted to be variadic to work with event logs with any number of topics. Also uncovered issue with Dai and TrueUSD that means they doesn't really conform to the ERC20 standard. this is because they named their arguments to standard events like Approval and Trasnfer differently (e.g. Approval(src address, guy address, wad uint) and Approval(owner address, spender address, value uint) instead of the standard which is Approval(tokenOwner address, spender address, tokens uint)). This causes incompatibility with generic ERC20 entities and converters for these events.

examples/generic/config.go

@@ -0,0 +1,38 @@
+// Copyright 2018 Vulcanize
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package generic
+
+import (
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/vulcanize/vulcanizedb/examples/constants"
+)
+
+type ContractConfig struct {
+	Address    string
+	Abi        string
+	ParsedAbi  abi.ABI
+	FirstBlock int64
+	LastBlock  int64
+	Name       string
+}
+
+var DaiConfig = ContractConfig{
+	Address:    constants.DaiContractAddress,
+	Abi:        constants.DaiAbiString,
+	ParsedAbi:  constants.ParsedDaiAbi,
+	FirstBlock: int64(4752008),
+	LastBlock:  -1,
+	Name:       "Dai",
+}

examples/generic/helpers/helpers.go

@@ -0,0 +1,66 @@
+// Copyright 2018 Vulcanize
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package helpers
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+)
+
+func ConvertToLog(watchedEvent core.WatchedEvent) types.Log {
+	allTopics := []string{watchedEvent.Topic0, watchedEvent.Topic1, watchedEvent.Topic2, watchedEvent.Topic3}
+	var nonNilTopics []string
+	for _, topic := range allTopics {
+		if topic != "" {
+			nonNilTopics = append(nonNilTopics, topic)
+		}
+	}
+	return types.Log{
+		Address:     common.HexToAddress(watchedEvent.Address),
+		Topics:      createTopics(nonNilTopics...),
+		Data:        hexutil.MustDecode(watchedEvent.Data),
+		BlockNumber: uint64(watchedEvent.BlockNumber),
+		TxHash:      common.HexToHash(watchedEvent.TxHash),
+		TxIndex:     0,
+		BlockHash:   common.HexToHash("0x0"),
+		Index:       uint(watchedEvent.Index),
+		Removed:     false,
+	}
+}
+
+func createTopics(topics ...string) []common.Hash {
+	var topicsArray []common.Hash
+	for _, topic := range topics {
+		topicsArray = append(topicsArray, common.HexToHash(topic))
+	}
+	return topicsArray
+}
+
+func BigFromString(n string) *big.Int {
+	b := new(big.Int)
+	b.SetString(n, 10)
+	return b
+}
+
+func GenerateSignature(s string) string {
+	eventSignature := []byte(s)
+	hash := crypto.Keccak256Hash(eventSignature)
+	return hash.Hex()
+}