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Clay Ferguson
17 Aug 2009, 12:48 PM
We are implementing (at CA) a web app that needs to display charts in the browser as well as generate reports on the back end, even perhaps when no users (browsers) are even logged on. So we are hoping the chart API inside GXT can somehow be used independently from any browser component, and used to generate chart image (PNG) totally from data existing only on the web server? Anybody know if this is possible? Thanks in advance.

Arno.Nyhm
19 Aug 2009, 4:42 AM
for this you should use more a pure java solution like http://www.jfree.org/jfreechart/ or others

Clay Ferguson
19 Aug 2009, 7:15 AM
Thanks Arno. We are aware of JFreeChart. So let me clarify our exact situation (choice).

We are currently planning to use BIRT charting engine however (available here http://download.eclipse.org/birt/downloads/build.php?build=R-R1-2_5_0-200906180630) because our app generates its reports using BIRT. However, we were hoping for the charts we show in reports to 'look the same' and have the 'same set of capabilities' as what is shown in the browser interactively when a user requests an on-demand chart outside the context of reporting. So inclusion of a GXT-generated chart into a report would be an option (provided that GXT allowed it). BIRT can render a chart into a PNG file (or stream) completely on the back-end which means BIRT can provide for us the browser-viewing as well as report-inclusion. However GXT is limited to using 'only' in the browser (afaik). I personally think this is a mistake. If GXT has the 'technical capability' of doing chart rendering, it should allow the server to emit the image date to a non-browser destination, so that apps like ours can both 1) display charts in GXT windows, and 2) easily do 'whatever else' we want with the chart images, such as includeing in reports or whatever. That's the choice we are making. If GXT charting can't do everything we need then we will simply not use ANY GXT charting whatsoever in our app - because we want a consistent look for charts.

Anyone having any comments, I appreciate, any help. thanks.

Arno.Nyhm
19 Aug 2009, 8:26 AM
GXT charting is just a wrapper to use Open Flash Chart

and Open Flash Chart is only a client side solution for charts.

there are 2 functions in OFC for getting the binary and posting a screenshot to server. but for this you need flash runnig.

please look here:
http://teethgrinder.co.uk/open-flash-chart/

Clay Ferguson
19 Aug 2009, 8:38 AM
Arno, thanks for the info. We have the need to run reports on the back end (at scheduled times) even when there are no logged in users, so anything involving a browser won't work for us, unfortunately. We need an API (black box) that takes data as input, and spits out chart images as the output. Cannot require any browser in the loop. So at least we know we made the right decision that GXT is not the right tool for our charting. But we still love everything else about GXT!!! Of course when we display charts it *will* still be inside a GXT window!