Fix email template

The Email notifier was using `map[string]interface{}` to "put" the
information (like Service and Failure struct) into the template.
The value of a map can only be used with `{{ index . "Service" }}` in a
GoLang template.
To simplify – and reduce the needed changes – `emailOutgoing` now
contains for the `Data` field an extra struct with `Service` and
`Failure` fields.

This patch fixes #472.

notifiers/email.go

@@ -155,19 +155,27 @@ type emailOutgoing struct {
 	Subject  string
 	Template string
 	From     string
-	Data     interface{}
+	Data     emailData
 	Source   string
 	Sent     bool
 }
 
+type emailData struct {
+	Service services.Service
+	Failure failures.Failure
+}
+
 // OnFailure will trigger failing service
 func (e *emailer) OnFailure(s *services.Service, f *failures.Failure) error {
 	email := &emailOutgoing{
 		To:       e.Var2,
 		Subject:  fmt.Sprintf("Service %v is Failing", s.Name),
 		Template: mainEmailTemplate,
-		Data:     ToMap(s, f),
+		Data: emailData{
-		From:     e.Var1,
+			Service: *s,
+			Failure: *f,
+		},
+		From: e.Var1,
 	}
 	return e.dialSend(email)
 }
@@ -179,15 +187,18 @@ func (e *emailer) OnSuccess(s *services.Service) error {
 		To:       e.Var2,
 		Subject:  msg,
 		Template: mainEmailTemplate,
-		Data:     ToMap(s, nil),
+		Data: emailData{
-		From:     e.Var1,
+			Service: *s,
+			Failure: failures.Failure{},
+		},
+		From: e.Var1,
 	}
 	return e.dialSend(email)
 }
 
 // OnTest triggers when this notifier has been saved
 func (e *emailer) OnTest() (string, error) {
-	testService := &services.Service{
+	testService := services.Service{
 		Id:             1,
 		Name:           "Example Service",
 		Domain:         "https://www.youtube.com/watch?v=-u6DvRyyKGU",
@@ -206,8 +217,11 @@ func (e *emailer) OnTest() (string, error) {
 		To:       e.Var2,
 		Subject:  subject,
 		Template: mainEmailTemplate,
-		Data:     testService,
+		Data: emailData{
-		From:     e.Var1,
+			Service: testService,
+			Failure: failures.Failure{},
+		},
+		From: e.Var1,
 	}
 	err := e.dialSend(email)
 	return subject, err

utils/replacer.go

@@ -2,32 +2,23 @@ package utils
 
 import (
 	"bytes"
-	"fmt"
 	"text/template"
 )
 
 func ReplaceTemplate(tmpl string, data interface{}) string {
 	buf := new(bytes.Buffer)
-	var varStr string
+
-	switch fmt.Sprintf("%T", data) {
-	case "*services.Service":
-		varStr = "Service"
-	case "*failures.Failure":
-		varStr = "Failure"
-	default:
-		varStr = "Object"
-	}
-	injectVars := make(map[string]interface{})
-	injectVars[varStr] = data
 	slackTemp, err := template.New("replacement").Parse(tmpl)
 	if err != nil {
 		Log.Error(err)
 		return err.Error()
 	}
-	err = slackTemp.Execute(buf, injectVars)
+
+	err = slackTemp.Execute(buf, data)
 	if err != nil {
 		Log.Error(err)
 		return err.Error()
 	}
+
 	return buf.String()
 }