AccessControl: Extend scope parameters with extra params from context (#39722)

* AccessControl: Extend scope parameters with extra params from context

Co-authored-by: Emil Tullstedt <emil.tullstedt@grafana.com>

pkg/services/accesscontrol/scope.go

@@ -18,8 +18,14 @@ func Scope(parts ...string) string {
 	return b.String()
 }
 
-// Parameter returns injectable scope part
+// Parameter returns injectable scope part, based on URL parameters.
 // e.g. Scope("users", Parameter(":id")) or "users:" + Parameter(":id")
 func Parameter(key string) string {
-	return fmt.Sprintf(`{{ index . "%s" }}`, key)
+	return fmt.Sprintf(`{{ index .URLParams "%s" }}`, key)
+}
+
+// Field returns an injectable scope part for selected fields from the request's context available in accesscontrol.ScopeParams.
+// e.g. Scope("orgs", Parameter("OrgID")) or "orgs:" + Parameter("OrgID")
+func Field(key string) string {
+	return fmt.Sprintf(`{{ .%s }}`, key)
 }