Dashboard: When saving a dashboard and another user has made changes inbetween, the user is promted with a warning if he really wants to overwrite the other's changes, Closes #718

pkg/api/dashboard.go

@@ -77,14 +77,18 @@ func PostDashboard(c *middleware.Context, cmd m.SaveDashboardCommand) {
 	err := bus.Dispatch(&cmd)
 	if err != nil {
 		if err == m.ErrDashboardWithSameNameExists {
-			c.JsonApiErr(400, "Dashboard with the same title already exists", nil)
+			c.JSON(412, util.DynMap{"status": "name-exists", "message": err.Error()})
+			return
+		}
+		if err == m.ErrDashboardVersionMismatch {
+			c.JSON(412, util.DynMap{"status": "version-mismatch", "message": err.Error()})
 			return
 		}
 		c.JsonApiErr(500, "Failed to save dashboard", err)
 		return
 	}
 
-	c.JSON(200, util.DynMap{"status": "success", "slug": cmd.Result.Slug})
+	c.JSON(200, util.DynMap{"status": "success", "slug": cmd.Result.Slug, "version": cmd.Result.Version})
 }
 
 func GetHomeDashboard(c *middleware.Context) {

pkg/models/dashboards.go

@@ -11,6 +11,7 @@ import (
 var (
 	ErrDashboardNotFound           = errors.New("Account not found")
 	ErrDashboardWithSameNameExists = errors.New("A dashboard with the same name already exists")
+	ErrDashboardVersionMismatch    = errors.New("The dashboard has been changed by someone else")
 )
 
 type Dashboard struct {
@@ -58,6 +59,10 @@ func (cmd *SaveDashboardCommand) GetDashboardModel() *Dashboard {
 
 	if dash.Data["id"] != nil {
 		dash.Id = int64(dash.Data["id"].(float64))
+
+		if dash.Data["version"] != nil {
+			dash.Version = int(dash.Data["version"].(float64))
+		}
 	}
 
 	return dash
@@ -79,7 +84,8 @@ func (dash *Dashboard) UpdateSlug() {
 //
 
 type SaveDashboardCommand struct {
-	Dashboard map[string]interface{} `json:"dashboard"`
+	Dashboard map[string]interface{} `json:"dashboard" binding:"Required"`
+	Overwrite bool                   `json:"overwrite"`
 	OrgId     int64                  `json:"-"`
 
 	Result *Dashboard

pkg/services/sqlstore/dashboard.go

@@ -28,13 +28,30 @@ func SaveDashboard(cmd *m.SaveDashboardCommand) error {
 			return err
 		}
 
-		if hasExisting && dash.Id != existing.Id {
-			return m.ErrDashboardWithSameNameExists
+		if hasExisting {
+			// another dashboard with same name
+			if dash.Id != existing.Id {
+				if cmd.Overwrite {
+					dash.Id = existing.Id
+				} else {
+					return m.ErrDashboardWithSameNameExists
+				}
+			}
+			// check for is someone else has written in between
+			if dash.Version != existing.Version {
+				if cmd.Overwrite {
+					dash.Version = existing.Version
+				} else {
+					return m.ErrDashboardVersionMismatch
+				}
+			}
 		}
 
 		if dash.Id == 0 {
 			_, err = sess.Insert(dash)
 		} else {
+			dash.Version += 1
+			dash.Data["version"] = dash.Version
 			_, err = sess.Id(dash.Id).Update(dash)
 		}