model: Always pass *sql.Tx to CRUD methods

When nesting objects like steps into other objects like recipes it is
required to pass a *sql.Tx value to the CRUD methods of the inner
object to be able to roll back the whole transaction.

The top level object used to be responsible for the creation of this
*sql.Tx inside its CRUD methods.

This is now moved to the caller of the CRUD methods (here the HTTP
handler function). The advantage is that all CRUD methods now accept a
*sql.Tx as only argument which makes those methods more consistent.

1 files changed, 14 insertions, 1 deletions

diff --git a/view/recipe.go b/view/recipe.go
index 0b545d9..52b7a7e 100644
--- a/view/recipe.go
+++ b/view/recipe.go
@@ -12,7 +12,20 @@ func RecipeRead(w http.ResponseWriter, r *http.Request) {
 	recipe := model.Recipe{}
 	recipe.Id = mux.Vars(r)[`id`]
 
-	err := recipe.Read()
+	tx, err := model.NewTx()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	err = recipe.Read(tx)
+	if err != nil {
+		model.Rollback(tx)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	err = tx.Commit()
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return