[Swansea Hackspace] Raspberry Pi - kiosk mode

[Iain Menzies-Runciman]

Another option would be to use WebSockets

Create a WebSocket Server (I am using https://pypi.python.org/pypi/websockets <https://pypi.python.org/pypi/websockets> for one of my projects)

Then create a WebSocket call from within the Web Page.

Your server could then not only supply any changes dynamically, it could then also act as a watchdog timer on the requests from the client - e.g. if it has not been asked for a information refresh in X minutes, then it is a fair guess that there is something wrong.

If want more details about how it could work, let me know.

Regards,
Ming

> On 23 Jan 2015, at 21:54, Emyr Morris <em at preseli.com> wrote:
> 
> yessss.... ajax - I was hoping to avoid ajax
> 
> Just as I pushed the send button on my initial email JS and AJAX came to my mind.
> 
> the project started off easy, I was going to just supply JPEGs on a memory stick plugged into the tellies
> 
> Then he said about turning things on and off... changing prices on a weekly basis, and then wanting it controlled from his ipad
> 
> that is when it became a client server setup
> 
> that was the point I should have jacked the price up significantly to push him back to keeping it simple, but I am a sucker for a challenge.
> 
> It is all databased so AJAX isn't a problem
> 
> I have really optimised all the files so a refresh isn't at all bad, the nice HD background is the slowest thing loading.
> 
> what is scary though is if it loses connection to the server and the customers don't have a menu to look at. There a JS solution would be much better as it could cache data until it gets a new connection
> 
> I had thought of doing a cron job to detect if it had lost the server connection, and if so it would simply pipe a pre-defined screen capture to /dev/fb0
> 
> 
> 
> On 23 January 2015 at 21:41, Justin Mitchell <justin at discordia.org.uk <mailto:justin at discordia.org.uk>> wrote:
> On Fri, 2015-01-23 at 20:28 +0000, Emyr Morris wrote:
> 
> > I was hoping to have something monitor chromium and if it detected
> > that the browser had frozen / stopped responding or hadn't refreshed
> > for a certain period of time, it would close the browser and re-open
> > it
> >
> >
> > I thought I had found an example a few months ago and bookmarked it,
> > but I can not for the life of me find the example again.
> >
> >
> > for example, I have a web page that is refreshed every 5 mins, if
> > chromium has not refreshed in 10 mins it needs to be restarted.
> >
> >
> > currently I am using a very simple
> > <meta http-equiv="refresh" content="120">
> > to reload the page,
> > I would value advice. Thanks
> 
> If there is a webserver on the pi have some javascript polling a simple
> cgi script (a bash script would do) via ajax, so it isnt disturbing the
> main page.
> 
> its easy enough to check that a process is still running from a shell
> script, but thats no indication that the page involved is still
> running/reloading.
> 
> Whilst there may be some cache and status files that belong to the
> browser, i dont imagine that it would be a terribly reliable indication
> of anything.
> 
> as an aside, those kind of page reloads are awefully klunky and
> disruptive, if you need any guidance on ajax, jquery, and other more
> modern stuff I or one of the others will gladly help i'm sure.
> 
> 
> 
> _______________________________________________
> Hackspace mailing list
> Hackspace at swansea.hackspace.org.uk <mailto:Hackspace at swansea.hackspace.org.uk>
> http://swansea.hackspace.org.uk/mailman/listinfo/hackspace <http://swansea.hackspace.org.uk/mailman/listinfo/hackspace>
> 
> 
> 
> -- 
> This e-mail and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed.
>  
> Mae'r e-bost hwn ac unrhyw ffeiliau a drosglwyddir gydag ef yn gyfrinachol ac at ddefnydd yr unigolyn neu'r corff y cyfeiriwyd hwy atynt yn unig.
> _______________________________________________
> Hackspace mailing list
> Hackspace at swansea.hackspace.org.uk
> http://swansea.hackspace.org.uk/mailman/listinfo/hackspace

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://swansea.hackspace.org.uk/pipermail/hackspace/attachments/20150124/b976551d/attachment.html>