Handle events

- Adds interfaces for developers to build handlers that update data in
response to log events
- Resolves #29

pkg/core/blockchain.go

@@ -3,10 +3,14 @@ package core
 import "math/big"
 
 type Blockchain interface {
+	GetAttribute(contract Contract, attributeName string, blockNumber *big.Int) (interface{}, error)
+	GetAttributes(contract Contract) (ContractAttributes, error)
 	GetBlockByNumber(blockNumber int64) Block
+	GetLogs(contract Contract, startingBlockNumber *big.Int, endingBlockNumber *big.Int) ([]Log, error)
 	LastBlock() *big.Int
 	Node() Node
-	GetAttributes(contract Contract) (ContractAttributes, error)
-	GetAttribute(contract Contract, attributeName string, blockNumber *big.Int) (interface{}, error)
-	GetLogs(contract Contract, startingBlockNumber *big.Int, endingBlockNumber *big.Int) ([]Log, error)
+}
+
+type ContractDataFetcher interface {
+	FetchContractData(abiJSON string, address string, method string, methodArg interface{}, result interface{}, blockNumber int64) error
 }

pkg/core/node_info.go

@@ -2,7 +2,7 @@ package core
 
 type Node struct {
 	GenesisBlock string
-	NetworkId    float64
-	Id           string
+	NetworkID    float64
+	ID           string
 	ClientName   string
 }

pkg/core/watched_event_log.go

@@ -1,14 +1,15 @@
 package core
 
 type WatchedEvent struct {
-	Name        string `json:"name"`                           // name
-	BlockNumber int64  `json:"block_number" db:"block_number"` // block_number
-	Address     string `json:"address"`                        // address
-	TxHash      string `json:"tx_hash" db:"tx_hash"`           // tx_hash
-	Index       int64  `json:"index"`                          // index
-	Topic0      string `json:"topic0"`                         // topic0
-	Topic1      string `json:"topic1"`                         // topic1
-	Topic2      string `json:"topic2"`                         // topic2
-	Topic3      string `json:"topic3"`                         // topic3
-	Data        string `json:"data"`                           // data
+	LogID       int64  `json:"log_id" db:"id"`
+	Name        string `json:"name"`
+	BlockNumber int64  `json:"block_number" db:"block_number"`
+	Address     string `json:"address"`
+	TxHash      string `json:"tx_hash" db:"tx_hash"`
+	Index       int64  `json:"index"`
+	Topic0      string `json:"topic0"`
+	Topic1      string `json:"topic1"`
+	Topic2      string `json:"topic2"`
+	Topic3      string `json:"topic3"`
+	Data        string `json:"data"`
 }