Add get followers

service/api/helpers/api-helpers.go

@@ -0,0 +1,42 @@
+package helpers
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/notherealmarco/WASAPhoto/service/database"
+	"github.com/sirupsen/logrus"
+)
+
+func DecodeJsonOrBadRequest(r io.Reader, w http.ResponseWriter, v interface{}, l logrus.FieldLogger) bool {
+
+	err := json.NewDecoder(r).Decode(v)
+	if err != nil {
+		SendInternalError(err, "Error decoding json", w, l)
+		return false
+	}
+	return true
+}
+
+func VerifyUserOrNotFound(db database.AppDatabase, uid string, w http.ResponseWriter) bool {
+
+	user_exists, err := db.UserExists(uid)
+
+	if err != nil {
+		SendInternalError(err, "Error verifying user existence", w, nil)
+		return false
+	}
+
+	if !user_exists {
+		w.WriteHeader(http.StatusNotFound)
+		return false
+	}
+	return true
+}
+
+func SendInternalError(err error, description string, w http.ResponseWriter, l logrus.FieldLogger) {
+	w.WriteHeader(http.StatusInternalServerError)
+	l.WithError(err).Error(description)
+	w.Write([]byte(description)) // todo: maybe in json. But it's not important to send the full error to the client
+}