When the "length of visits" widget is configured to display a pie chart (and only in that configuration), any resizing of the browser window causes the chart to vanish from the page.
Tested in Firefox 12, Opera 11.64, Chromium 11 and IE 9.
When that happens, hovering over the area where the pie chart should have been generates numerous JS errors. These errors are harmless and I wouldn't have noticed them if it hadn't had Firebug installed in Firefox.
Attachment: The widget that is affected by the issue.
MWSnap 2012-08-03, 12_51_19 - Piwik widget.png
Attachment: Before resizing
MWSnap 2012-08-03, 16_17_43 - demo.piwik.org - widget before resizing.png
Attachment: After resizing
MWSnap 2012-08-03, 16_17_59 - demo.piwik.org - widget after resizing.png
Attachment: Error log in Firebug's console
MWSnap 2012-08-09, 13_59_23-Piwik-pie chart errors in Firebug.png
Thanks for the report. Do you mean the graph "Visits per visit duration" ? For me it works well in firefox. Can you reproduce on demo ? which URL ?
Yes, I mean the graph that shows how long visits last. Please see the attachment for a screenshot of the widget.
I am using 1.8.2 on my website, waavsolutions.com
Yes I can reproduce the problem on demo.piwik.org (see attached files for screen captures in FF 12.0) in both FF 12.0 and Opera 11.64.
To make the graph appear again, you need to click the pie chart icon.
I have just added a screenshot of the errors logged in the Firebug console. Maybe that it'll help pinpointing the root cause of this ungodly vanishment
(In ) Fixes #3295, make sure Piwik JQPlot class doesn't transform pie chart data twice.