How to check whether a resource is available yet in online experiment?

Online experiments
2

Have a look at the download resources section of my code snippets page

However, don’t use Download Resources in combination with the latest version of PsychoPy – though the test should still work

Each Frame
try {
psychoJS.serverManager.getResource(expInfo["participant"] + ".jpg");
    continueRoutine = false;
} catch (e) {}