Merge pull request #155 from jehiah/flag_support_155

Simpler integration of config and the stdlib flag package

config_flag.go

@@ -0,0 +1,31 @@
+package nsq
+
+import (
+	"strings"
+)
+
+// ConfigFlag wraps a Config and implements the flag.Value interface
+type ConfigFlag struct {
+	*Config
+}
+
+// Set takes a comma separated value and follows the rules in Config.Set
+// using the first field as the option key, and the second (if present) as the value
+func (c *ConfigFlag) Set(opt string) (err error) {
+	parts := strings.SplitN(opt, ",", 2)
+	key := parts[0]
+
+	switch len(parts) {
+	case 1:
+		// default options specified without a value to boolean true
+		err = c.Config.Set(key, true)
+	case 2:
+		err = c.Config.Set(key, parts[1])
+	}
+	return
+}
+
+// String implements the flag.Value interface
+func (c *ConfigFlag) String() string {
+	return ""
+}

config_flag_test.go

@@ -0,0 +1,25 @@
+package nsq_test
+
+import (
+	"flag"
+
+	"github.com/bitly/go-nsq"
+)
+
+func ExampleConfigFlag() {
+	cfg := nsq.NewConfig()
+	flagSet := flag.NewFlagSet("", flag.ExitOnError)
+
+	flagSet.Var(&nsq.ConfigFlag{cfg}, "consumer.options", "option to passthrough to nsq.Consumer (may be given multiple times, http://godoc.org/github.com/bitly/go-nsq#Config.Set)")
+	flagSet.PrintDefaults()
+
+	err := flagSet.Parse([]string{
+		"-consumer.options=heartbeat_interval,1s",
+		"-consumer.options=max_attempts,10",
+	})
+	if err != nil {
+		panic(err.Error())
+	}
+	println("HeartbeatInterval", cfg.HeartbeatInterval)
+	println("MaxAttempts", cfg.MaxAttempts)
+}