Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Fri, 14 Jun 2013 11:20:16 -0400

On Fri, Jun 14, 2013 at 10:19 AM, Jeremy Iken <[email protected]<mailto:[email protected]>> wrote:
Is webOPI the best for mobile/tablets? Is it strong enough?
Depends on how you define best.

Not best as in: The highest performant.
If you want something that works the best on an iPad, you need to implement that in ObjectiveC.
Android device, you need to implement that in Java-for-Android.
Web browsers in general, you need to implement that in HTML and Java Script on the client side, custom servlets on the server side, and do that for Internet Explorer as well as the rest.

The Webopi uses Eclipse RAP, meaning: It basically replaces the graphics library of the standalone RCP application (SWT) with one for a web application.
Instead of drawing a line on the screen, it remembers that you wanted to draw a line on the screen, sends Java script to the web client so that the web client performs "long polls" for updates, and the next time the web client asks, it will get the message: "Please draw a line".
This allowed us to make the CSS BOY displays available to web clients. ITER recently did that for the Data Browser.
It's very convenient that we can use the same source code, the same *.opi files, and also display them on the web.
This is "the best" if you use CSS on a beam line, your people know how to create *.opi files, and now they would like to see one or two simple *.opi files on the web.
It allows a beam line person to quickly create a display file with key parameters that they want to monitor over the weekend.
Just copy those *.opi files into a directory that's served by the webopi.
It's perfect if the 3 people working on the beam line look at it every once in a while.

But nothing in there is optimized for performance. It sucks if you want to use this for THE status display of your machine, viewed by 50 people each morning, displayed 24/7 on numerous monitors throughout the facility, because basically everybody who views this starts an instance of CSS within the web server. For that you need to do more than just copy an existing *.opi file to a webopi directory, and instead create a web application that creates the information that you want once, and serves it to N people without hardly any added overhead for N+1.

-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System