func setAppEngineContext(next alice.ContextHandler) alice.ContextHandler {
fn := func(empty appContext.Context, w http.ResponseWriter, r *http.Request) {
// we hang on our empty parent context the appengine context for further middlewares
newContext := appengine.WithContext(empty, r)
next.ServeHTTPContext(newContext, w, r)
}
return alice.ContextHandlerFunc(fn)
}
// ContextMiddleware bootstraps the context to be able to contact with App Engine.
func ContextMiddleware(ctx context.Context, w http.ResponseWriter, r *http.Request, next NextMiddlewareFn) error {
return next(appengine.WithContext(ctx, r))
}