Prevent participants from continuing if resources weren't downloaded

Hi Irene,

If you experience issues with preloading zip files, I suggest you try using PennController 2.1 beta, on which I am still currently working, where I revise the way zip files are downloaded

Then if you still need to detect failure to download the zip file, you could add a file named AA.js to your Modules folder (you want the filename to come before PennController.js in an alphanumeric order) with a content like this:

const zipError = ()=>{
    const pe = document.querySelector(".PennController-PennController");
    const parent = pe.parentElement;
    pe.remove();
    const warning = document.createElement("P");
    warning.innerHTML = "There was a problem loading resources for this experiment. Please reload this page to try again.";
    parent.append(warning);
};

const oldFetch = window.fetch;
window.fetch = function(...args){
    const r = oldFetch.apply(this, args);
    if (typeof(args[0])=="string" && args[0].match(/\.zip$/i))
        r.catch(zipError);
    return r;
}

And to fully capture all the errors in the download process, also add this at the top of your project’s main.js script:

PennController._AddElementType("dummyelementname", function(PennEngine) {
    const olderror = PennEngine.debug.error;
    PennEngine.debug.error = function(...args) {
        if (typeof(args[0])=="string" && args[0].match(/Error downloading .+zip/))
            zipError();
        return olderror.apply(this, args);
    }
})

Let me know if you have questions

Jeremy