I've been asked to display some meter data on the web and I need preliminary
advice.
We have several hundred meters on site, with a system that writes out xml
files at 10 second intervals containing their data. (These files are
overwritten every 10 seconds, not appended to.)
First, I need to display two numeric pieces of this data just as numbers in
a web page. Naturally that's easy enough: where I'm stumped is REFRESHING
that data when it's updated every 10 seconds. Of course I don't want to
refresh the whole page, but only update a particular number when its
associated xml file is updated.
I've seen this done client side with javascript, but it was pretty cludgey.
Can ASP.NET help me here with a kind of persistant connection to these xml
files? (I thought the DataSet did such business out of the box, but it
doesn't as far as I can tell.)
Second, I need to use this data later for graphic trend displays. In other
words, I need to show in graph or chart form how each of these meters is
performing over time. Since the xml files are overwritten, I obviously have
to persist each piece of data somehow. I can think of any number of ways to
do this, but none of them seem too elegant. Any advice anyone might have
will help me think this through.
