model: Replace global db variable by custom type

Reducing global variables makes it easier to understand functions
independently of the rest of the code.

Adding the new model.DB type as a custom variant of the sql.DB type
makes it possible to write methods for the database which makes the code
way more readable.

1 files changed, 37 insertions, 35 deletions

diff --git a/view/recipe.go b/view/recipe.go
index d77d771..0578107 100644
--- a/view/recipe.go
+++ b/view/recipe.go
@@ -8,47 +8,49 @@ import (
 	"github.com/gorilla/mux"
 )
 
-func RecipeRead(w http.ResponseWriter, r *http.Request) {
-	recipe := model.Recipe{}
-	recipe.Id = mux.Vars(r)[`id`]
-
-	var obj model.Object = &recipe
-	err := model.Transaction(obj.Read)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
+func RecipeRead(db *model.DB) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		recipe := model.Recipe{}
+		recipe.Id = mux.Vars(r)[`id`]
 
-	template := "recipe"
-	view, ok := r.URL.Query()["view"]
-	if ok {
-		if len(view) > 1 {
-			http.Error(w, "More than one 'view' parameter given in URL", http.StatusBadRequest)
+		var obj model.Object = &recipe
+		err := db.Transaction(obj.Read)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
-		template = view[0]
-	}
 
-	is_valid := false
-	valid_templates := []string{
-		"recipe",
-		"recipe-edit",
-		"recipe-confirm-deletion",
-	}
-	for _, v := range valid_templates {
-		if template == v {
-			is_valid = true
+		template := "recipe"
+		view, ok := r.URL.Query()["view"]
+		if ok {
+			if len(view) > 1 {
+				http.Error(w, "More than one 'view' parameter given in URL", http.StatusBadRequest)
+				return
+			}
+			template = view[0]
 		}
-	}
-	if !is_valid {
-		http.Error(w, "Unsupported view: "+template, http.StatusBadRequest)
-		return
-	}
 
-	err = html.ExecuteTemplate(w, template, recipe)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
+		is_valid := false
+		valid_templates := []string{
+			"recipe",
+			"recipe-edit",
+			"recipe-confirm-deletion",
+		}
+		for _, v := range valid_templates {
+			if template == v {
+				is_valid = true
+			}
+		}
+		if !is_valid {
+			http.Error(w, "Unsupported view: "+template, http.StatusBadRequest)
+			return
+		}
+
+		err = html.ExecuteTemplate(w, template, recipe)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
 	}
 }