How best to handle preloader errors?

nateTrunk · March 29, 2021, 10:42am

Hi all,

Wondering how people generally handle errors during preloader? E.g. an asset not loading halts the preloader due to connectivity errors when playing on 3G/4G.

Have looked through the PC preloader source and can’t see any events for errors - happy to add a Pull Request for the future, but wondered if there was an elegant way of handling preloader error/freezes as it stands?

Thanks in advance,
Nate.

Kulodo133 · March 29, 2021, 11:12am

Hi

I did notice this recently. The code in onAssetLoad and onAssetError is the same,. I wonder if the error event is not fired?

github.com

playcanvas/engine/blob/50364adc9f9e2601aeb3749941e493c703c2802e/src/framework/application.js#L955


    self.fire('preload:progress', count() / total);
    if (_assets.done())
        done();
};
// for each asset
for (i = 0; i < assets.length; i++) {
    if (!assets[i].loaded) {
        assets[i].once('load', onAssetLoad);
        assets[i].once('error', onAssetError);
        this.assets.load(assets[i]);
    } else {
        _assets.inc();
        self.fire("preload:progress", count() / total);
        if (_assets.done())
            done();
    }
}

yaustar · March 29, 2021, 11:19am

We do have a ‘retry’ mechanism where if an error occurs, it attempts to retry:

However, that depends on an error being thrown. The engine doesn’t yet handle timeouts or connections that are active but no actual network transfer is taking place.

There’s a feature request for this here: https://github.com/playcanvas/engine/issues/2021 It’s tricky as not all asset loads are via XHR (eg images for textures)