Merge pull request nanmu42#24 from nanmu42/develop

add NewCustomized() so that client works with etherscan-family API like BscScan

Author: nanmu42

README.md

@@ -6,7 +6,7 @@
 [![GoDoc](https://godoc.org/github.com/nanmu42/etherscan-api?status.svg)](https://godoc.org/github.com/nanmu42/etherscan-api)
 [中文文档](https://github.com/nanmu42/etherscan-api/blob/master/README_ZH.md)
 
-Go bindings to the Etherscan.io API, with nearly Full implementation(accounts, transactions, tokens, contracts, blocks, stats), full network support(Mainnet, Ropsten, Kovan, Rinkby, Tobalaba), and only depending on standard library. :wink:
+Go bindings to the Etherscan.io API(and its families like BscScan), with nearly Full implementation(accounts, transactions, tokens, contracts, blocks, stats), full network support(Mainnet, Ropsten, Kovan, Rinkby, Tobalaba), and only depending on standard library. :wink:
 
 # Usage
 
@@ -22,6 +22,15 @@ func main() {
 	// create a API client for specified ethereum net
 	// there are many pre-defined network in package
 	client := etherscan.New(etherscan.Mainnet, "[your API key]")
+	
+	// or, if you are working with etherscan-family API like BscScan
+	//
+	// client := etherscan.NewCustomized(etherscan.Customization{
+    // Timeout:       15 * time.Second,
+    // Key:           "You key here",
+    // BaseURL:       "https://api.bscscan.com/api?",
+    // Verbose:       false,
+    // })
 
 	// (optional) add hooks, e.g. for rate limit
 	client.BeforeRequest = func(module, action string, param map[string]interface{}) error {

client.go

@@ -22,7 +22,6 @@ import (
 // Clients are safe for concurrent use by multiple goroutines.
 type Client struct {
 	coon    *http.Client
-	network Network
 	key     string
 	baseURL string
 
@@ -41,13 +40,45 @@ type Client struct {
 // New initialize a new etherscan API client
 // please use pre-defined network value
 func New(network Network, APIKey string) *Client {
+	return NewCustomized(Customization{
+		Timeout: 30 * time.Second,
+		Key:     APIKey,
+		BaseURL: fmt.Sprintf(`https://%s.etherscan.io/api?`, network.SubDomain()),
+	})
+}
+
+// Customization is used in NewCustomized()
+type Customization struct {
+	// Timeout for API call
+	Timeout time.Duration
+	// API key applied from Etherscan
+	Key string
+	// Base URL like `https://api.etherscan.io/api?`
+	BaseURL string
+	// When true, talks a lot
+	Verbose bool
+
+	// BeforeRequest runs before every client request, in the same goroutine.
+	// May be used in rate limit.
+	// Request will be aborted, if BeforeRequest returns non-nil err.
+	BeforeRequest func(module, action string, param map[string]interface{}) error
+
+	// AfterRequest runs after every client request, even when there is an error.
+	AfterRequest func(module, action string, param map[string]interface{}, outcome interface{}, requestErr error)
+}
+
+// NewCustomized initialize a customized API client,
+// useful when calling against etherscan-family API like BscScan.
+func NewCustomized(config Customization) *Client {
 	return &Client{
 		coon: &http.Client{
-			Timeout: 30 * time.Second,
+			Timeout: config.Timeout,
 		},
-		network: network,
-		key:     APIKey,
-		baseURL: fmt.Sprintf(`https://%s.etherscan.io/api?`, network.SubDomain()),
+		key:           config.Key,
+		baseURL:       config.BaseURL,
+		Verbose:       config.Verbose,
+		BeforeRequest: config.BeforeRequest,
+		AfterRequest:  config.AfterRequest,
 	}
 }