Topic: issue with XMLs


Question for Duane or other advanced widget developer.

I am trying to revive an app I made a long time ago: … 646/widget

I know there are not many people here anymore, but I think the app was filling a hole (sending messages between Chumbies or from web to a target Chumby), so I would like to make it work again.

I am pretty sure it worked up to a point, as I see messages getting posted, but then it stopped.

I reopened my fla file and identified that when the XML was on localhost, the swf file worked just fine. However, when targetting the same XML online (for instance: … feed.xml), it does not work anymore.
I am sure the web-based URL I pass to the XML reader is correct.

Anyone has experience fixing the issue or a working example of XML retrieval?
Did something change with how swf files can handle XMLs?

(super happy to re-use my chumby, my children love it!)

Re: issue with XMLs

The issue is likely with the https, not the XML.  The Flash Player on the chumby devices supports https only for the later versions of firmware, and the Sony dash doesn't support it at all.  And, unfortunately, even those devices that have https support use deprecated protocols.

On the website, the problem is likely cross-origin restrictions.   Unlike the old-school Adobe Flash Player plugin (RIP), the replacement (Ruffle) is restricted to Javascript's security rules, which generally precludes fetching data from another site unless that site explicitly grants permission to the origin site (it can allow everyone, or just specific sites, but the default is "only me" aka "same site policy").

Many chumby-authored widgets work around this by have the chumby content server make the call on its behalf, but this comes at a cost of bandwidth on the part of chumby, since it effectlvely becomes a gateway to the internet for all of the devices.

If you control the server feeding the XML, there are two fixes - for supporting the devices, support http in addition to https, and for supporting the site, add support for access control headers to grant permission to (at least) *  If you don't control the server, you can set up an additional server of your own to fetch the data from the offending server, and present with appropriate protocols and permissions to the client.

Re: issue with XMLs

Incidentally, when running the widget in the browser, open the developer tools and it will likely tell you what went wrong.

Re: issue with XMLs

Thanks Duane,

This is very useful, especially the trick for the browser.
I control the server that serves the XML.
I still had the crossdomain.xml from back in the day. The issue is likely with https://. I will check soon and post the solution when I find it. Unfortunately, while working on my Chumby, it fell and broke and I would need to re-solder the power supply :-( so I am a bit stuck at the moment.


Re: issue with XMLs

Just a small follow-up on this for future reference as I managed to solder the Chumby :-)

For the XML issue, it as coming from migrating to another host in the past 10 years, which enforced https:// automatically. Changing the config of the server to allow http:// solved the issue (though the widget lost some functionality, the configuration swf is not working anymore).
If anyone is still here, feel free to add the widget and we can send each other random messages :-)