allow unmarshalling consts as strings

cmd/webcmd/webcmd.conf-sample

@@ -10,10 +10,10 @@
 		{
 			"Title": "Ping",
 			"Execution": [
-				{"ParamType": 0, "Value": "/bin/ping"},
+				"/bin/ping",
-				{"ParamType": 0, "Value": "-c"},
+				"-c",
-				{"ParamType": 0, "Value": "4"},
+				"4",
-				{"ParamType": 0, "Value": "--"},
+				"--",
 				{"ParamType": 1, "Value": "example.com", "Description": "Target host"}
 			]
 		}

config.go

@@ -1,5 +1,10 @@
 package webcmd
 
+import (
+	"encoding/json"
+	"errors"
+)
+
 type ParamType int
 
 const (
@@ -16,15 +21,39 @@ const (
 )
 
 type InputParam struct {
-	Description string `json:",omitempty"` // only use for editable parameters
+	Description string `json:",omitempty"` // only used for editable parameters
 	ParamType   ParamType
 	Value       string
 }
 
+func (ip *InputParam) JSONUnmarshal(b []byte) error {
+	if b[0] == '"' {
+		ip.Description = ""
+		ip.ParamType = PARAMTYPE_CONST
+		return json.Unmarshal(b, &ip.Value)
+
+	} else if b[0] == '{' {
+		read := struct {
+			Description string `json:",omitempty"`
+			ParamType   ParamType
+			Value       string
+		}{}
+		err := json.Unmarshal(b, &read)
+		if err != nil {
+			return err
+		}
+		*ip = read
+		return nil
+
+	} else {
+		return errors.New("Malformed InputParam")
+	}
+}
+
 type CommandConfig struct {
 	Title      string
 	WorkingDir string       // default empty-string: getcwd()
-	Execution  []InputParam // TODO allow plain strings as a shorthand for PARAMTYPE_CONST
+	Execution  []InputParam // Can be unmarshalled using plain strings
 }
 
 type AppConfig struct {