Clearing RiseVision's "DummyVar" for Web Page Widget Refresh

  • 1
  • Problem
  • Updated 3 years ago
  • Solved
Hello all,

I have an issue while using a Web Page Widget with a 1 min refresh. 
I have an HTM file that I have update several times a day.
This HTM file is read by the Web Page Widget and it used to work great, but it seems that it's starting to "recycle" the dummyvar numbers. 
For example, the URL for the HTM looks something like "www.site.com/Lobby/Visitors.htm?dummyVar=6", but depending on what number follows "Var=", I get different versions of this file throughout it's history. 
Is there anyway to have Rise Vision actually do a refresh rather than reusing dummyVars that once had a cached version of this file? Or is there a way to disable clientside caching entirely to force it to reach out to the webserver to get the latest each and every refresh?

Thanks to anyone that is willing to help!
Photo of Jamco America IT Dept.

Posted 3 years ago

  • 1
Photo of Blake Freeman

Blake Freeman, Official Rep

  • 36,116 Points 20k badge 2x thumb
Jamco America IT Dept,

I'm afraid I'm not quite certain how your setup functions. Can you elaborate a little bit on the "dummyvars" that you use and how they relate to your presentation?

There is no way to disable client side caching, so that would not be an option for a solution. I think we're going to need to look at how your webserver works, and what URL you are pointing the Web Page Widget to present.
Hello Blake and thanks for the response.

Currently the presentation is using the Web Page widget which is looking at a simple HTM page which we have on our Intranet.
This web page is modified several times throughout the day, so we need it to refresh for the presentation.
Currently, the refresh rate on the Web Page widget is set to 1 minute.
I've noticed that the Rise Vision windows application uses what is known as "DummyVars" to try to pull a new request for the HTM document upon each/every refresh (every 1 minute). 
So when you view the source of the page that is viewed, you see something like "www.site.com/Lobby/Visitors.htm?dummyVar=6", then upon next refresh it'll show as ""www.site.com/Lobby/Visitors.htm?dummyVar=7" and so on as the dummyVar counter increases. 
In theory, this should be fine as the number keeps changing, but it seems that Chromium caches each instance of these requests separately and when the counter decides to start re-using the previous dummyVars (which it does), I get the old version of the cached HTM file. 

Testing locally on my Chrome Browser, a temporary fix was to go into Settings and Clear the browsers cache and that seemed to clear all the stored versions of the HTM file with the various dummyVar instances. However, this obviously isn't a feasible solution to do on a presentation machine with a file that updates randomly throughout the day.

I wish there was an easier way to explain it, but I hope that I have provided the extra bits of info that may help you understand the situation a bit better. 
Photo of Blake Freeman

Blake Freeman, Official Rep

  • 36,116 Points 20k badge 2x thumb
Thanks for the additional information. This is enough for me to go on right now. I'll get back to you when I have some ideas!
Photo of Stephen Garrett

Stephen Garrett, Champion

  • 2,674 Points 2k badge 2x thumb
Are you generating the web page yourselves? If so, you could maybe use a Javascript timer to call a newer version of the HTML. We use mustache templates to pull dynamic content into a predefined HTML structure. Then, you wouldn't need to rely on any kind of refresh from the web page widget.
Stephen,
The web page is generated on our end, but it's actually a published version of an Excel spread sheet. Excel 2010 has the option to publish to a HTM file upon save, so we have our receptionist update the excel spreadsheet with some information, and when she saves that file, it auto-publishes to the HTM file that is being displayed by RV. So unless there was a parent HTML page that contained a frame with that HTM page in it, I don't see this working. 
I appreciate the idea though!
Photo of Stephen Garrett

Stephen Garrett, Champion

  • 2,674 Points 2k badge 2x thumb
Yeah, that sounds like it would take some work. Good luck!
Stephen,
I'd like to say thank you for your suggestion as I actually used the premise to accomplish a work around solution to the primary problem.

By using the below HTML code, I was able to have a second page which framed the initial site, but forces a refresh every 30 seconds. With the webpage performing it's own refresh, I no longer rely on the Web Page Widget to do any refreshes which now stops the dummyVars from being an issue.

Hopefully this helps someone else later down the road.

HTML:
<head><meta http-equiv="refresh" content="30">
<iframe id="Iframe1" src="www.site.com/Lobby/Visitors.htm"; width="600" height="600" style="border:none"></iframe>
</head>
(Edited)
Photo of Stephen Garrett

Stephen Garrett, Champion

  • 2,674 Points 2k badge 2x thumb
Well done!
Photo of HSuarez

HSuarez

  • 11,896 Points 10k badge 2x thumb
Thanks for sharing your findings!
Photo of Blake Freeman

Blake Freeman, Official Rep

  • 36,116 Points 20k badge 2x thumb
Jamco America IT Dept,

Our Content team has let me know that they will be starting work on the Web Page Widget soon, and part of that working is resolving the issue that you have reported. If you would like, you can check out the feedback thread on the Web Page Widget here. It would be a good place to post any concerns with the current functionality of the widget.