Adding Variable method to spark code adaptor

examples/spark_core_variable.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/hybridgroup/gobot"
+	"github.com/hybridgroup/gobot/platforms/spark"
+)
+
+func main() {
+	gbot := gobot.NewGobot()
+
+	sparkCore := spark.NewSparkCoreAdaptor("spark", "53ff72065067544846101187", "f7e2983869e725addd416270cb055ba04a33fdad")
+
+	work := func() {
+		temp, err := sparkCore.Variable("temperature")
+
+		if err != nil {
+			fmt.Println(err.Error())
+		} else {
+			fmt.Printf("temp from variable is: %v", temp)
+		}
+	}
+
+	robot := gobot.NewRobot("spark",
+		[]gobot.Connection{sparkCore},
+		[]gobot.Device{},
+		work,
+	)
+
+	gbot.AddRobot(robot)
+
+	gbot.Start()
+}

platforms/spark/spark_core_adaptor.go

@@ -57,7 +57,7 @@ func (s *SparkCoreAdaptor) AnalogRead(pin string) (val int, err error) {
 
 	url := fmt.Sprintf("%v/analogread", s.deviceURL())
 
-	resp, err := s.postToSpark(url, params)
+	resp, err := s.requestToSpark("POST", url, params)
 	if err == nil {
 		val = int(resp["return_value"].(float64))
 		return
@@ -78,7 +78,7 @@ func (s *SparkCoreAdaptor) AnalogWrite(pin string, level byte) (err error) {
 		"access_token": {s.AccessToken},
 	}
 	url := fmt.Sprintf("%v/analogwrite", s.deviceURL())
-	_, err = s.postToSpark(url, params)
+	_, err = s.requestToSpark("POST", url, params)
 	return
 }
 
@@ -89,7 +89,7 @@ func (s *SparkCoreAdaptor) DigitalWrite(pin string, level byte) (err error) {
 		"access_token": {s.AccessToken},
 	}
 	url := fmt.Sprintf("%v/digitalwrite", s.deviceURL())
-	_, err = s.postToSpark(url, params)
+	_, err = s.requestToSpark("POST", url, params)
 	return err
 }
 
@@ -100,14 +100,24 @@ func (s *SparkCoreAdaptor) DigitalRead(pin string) (val int, err error) {
 		"access_token": {s.AccessToken},
 	}
 	url := fmt.Sprintf("%v/digitalread", s.deviceURL())
-	resp, err := s.postToSpark(url, params)
+	resp, err := s.requestToSpark("POST", url, params)
 	if err == nil {
 		val = int(resp["return_value"].(float64))
 		return
 	}
 	return -1, err
 }
 
+// Variable returns a core variable value,
+// returned value can be a float64 or a string
+func (s *SparkCoreAdaptor) Variable(name string) (val interface{}, err error) {
+	url := fmt.Sprintf("%v/%s?access_token=%s", s.deviceURL(), name, s.AccessToken)
+	resp, err := s.requestToSpark("GET", url, nil)
+	val = resp["result"]
+
+	return
+}
+
 // setAPIServer sets spark cloud api server, this can be used to change from default api.spark.io
 func (s *SparkCoreAdaptor) setAPIServer(server string) {
 	s.APIServer = server
@@ -129,10 +139,17 @@ func (s *SparkCoreAdaptor) pinLevel(level byte) string {
 	return "LOW"
 }
 
-// postToSpark makes POST request to spark cloud server, return err != nil if there is
+// requestToSpark makes request to spark cloud server, return err != nil if there is
 // any issue with the request.
-func (s *SparkCoreAdaptor) postToSpark(url string, params url.Values) (m map[string]interface{}, err error) {
-	resp, err := http.PostForm(url, params)
+func (s *SparkCoreAdaptor) requestToSpark(method string, url string, params url.Values) (m map[string]interface{}, err error) {
+	var resp *http.Response
+
+	if method == "POST" {
+		resp, err = http.PostForm(url, params)
+	} else if method == "GET" {
+		resp, err = http.Get(url)
+	}
+
 	if err != nil {
 		return
 	}

platforms/spark/spark_core_adaptor_test.go

@@ -110,7 +110,6 @@ func TestSparkCoreAdaptorAnalogRead(t *testing.T) {
 
 	val, _ = a.AnalogRead("A1")
 	gobot.Assert(t, val, 0)
-
 }
 
 func TestSparkCoreAdaptorPwmWrite(t *testing.T) {
@@ -195,8 +194,52 @@ func TestSparkCoreAdaptorDigitalRead(t *testing.T) {
 	gobot.Assert(t, val, -1)
 }
 
-func TestSparkCoreAdaptorSetAPIServer(t *testing.T) {
+func TestSparkCoreAdaptorVariable(t *testing.T) {
+	// When String
+	response := `{"result": "1"}`
+
+	a := initTestSparkCoreAdaptor()
+	testServer := getDummyResponseForPath("/"+a.DeviceID+"/variable_name", response, t)
+
+	a.setAPIServer(testServer.URL)
+
+	val, _ := a.Variable("variable_name")
+	gobot.Assert(t, val.(string), "1")
+	testServer.Close()
+
+	// When float
+	response = `{"result": 1.1}`
+	testServer = getDummyResponseForPath("/"+a.DeviceID+"/variable_name", response, t)
+
+	a.setAPIServer(testServer.URL)
+
+	val, _ = a.Variable("variable_name")
+	gobot.Assert(t, val.(float64), 1.1)
+	testServer.Close()
 
+	// When int
+	response = `{"result": 1}`
+	testServer = getDummyResponseForPath("/"+a.DeviceID+"/variable_name", response, t)
+
+	a.setAPIServer(testServer.URL)
+
+	val, _ = a.Variable("variable_name")
+	gobot.Assert(t, val.(float64), 1.0)
+	testServer.Close()
+
+	// When not existent
+	response = `{"ok": false, "error": "Variable not found"}`
+	testServer = getDummyResponseForPath("/"+a.DeviceID+"/not_existent", response, t)
+
+	a.setAPIServer(testServer.URL)
+
+	_, err := a.Variable("not_existent")
+	gobot.Assert(t, err.Error(), "Variable not found")
+
+	testServer.Close()
+}
+
+func TestSparkCoreAdaptorSetAPIServer(t *testing.T) {
 	a := initTestSparkCoreAdaptor()
 	apiServer := "new_api_server"
 	gobot.Refute(t, a.APIServer, apiServer)