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RSS good for feeds, not for real-time data transfer

I recently wrote about WidgetBox breaking my live stock quote widget by disallowing data in CSV text format when using their proxied XML-HTTP request functionality. (See "WidgetBox tightens up AJAX interface")

As an alternative, I set up a Yahoo! pipe to supply the data in RSS format, which seemed to work well.

The problem is when a person stays on the page hosting the widget in order to watch the quotes update throughput the day. After half an hour or so, the widget stops working. There appears to be some kind of strange caching going on that prevents any data from being returned. I tried the usual work-around: appending in the query string a key/value pair containing a random number but to no avail.

My eventual solution was to create a Google gadget with the same logic that retrieved data from the original source in CSV text format. This gadget was then embedded inside the WidgetBox widget.

With a little fooling around, I was able to pass the user configuration data through the WidgetBox widget to the Google widget and, once again, things seem to be working fine.

The bottom line is that RSS just does not seem to lend itself to continuous data retrieval for applications like real-time quotes. It is hard to be sure exactly where the problem lies but either WidgetBox or Yahoo! or both treat RSS as an information feed, not a raw data feed. As such, the assumption is that one wouldn't want to continuously retrieve an RSS feed as I have been trying to do.

So far, it appears the Google libraries offer more flexibility than the WidgetBox approach but at the cost of more programming effort. For those with good Javascript expertise, however, programming gadgets should not be too hard.

Posted by TradeRadarOperator at 4/27/2008 05:08:00 PM  


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