Setting the time period to 50 days makes the chart disappear without message.

[Heiko Graeber]

The BurndownChart macro is very useful to show the project's progress unless you need it for a longer period of time which is common in the projects I work for. One example for this is the following invocation:

[[BurndownChart(milestone=Release4.8, startdate=2009-06-10, enddate=2009-07-31)]]

which produces just an empty image tagged "Burndown". The macro might process a longer period of time or at least show a warning message to the user so [s]he might figure out how to use the macro in a way that works. Alternatively, this could be documented in the Wiki if it is not possible to fix the limitation.

I observed this using a Trac 0.10.4 installation.

[anonymous]

This is most likely to do with limit of google charts URL size. If you check url used by empty image and bring it up in a brower you will see the google chart error message if it is this.

[osimons]

#8686 closed as duplicate.

For server-side charts we can actually switch to 'POST' quite easily, so this patch should increase the limit from 2K to 16K (according to ​http://code.google.com/intl/no/apis/chart/faq.html#url_length):

estimationtools/utils.py

@@ -64 +64 @@
         return req.path_info == '/estimationtools/chart'
     def process_request(self, req):
         req.perm.require('TICKET_VIEW')
-        url = 'http://chart.apis.google.com/chart?%s' % req.args.get('data', '')
-        self.log.debug("Fetching chart using url: %s" % repr(url))
-        chart = urllib2.urlopen(url.encode('utf-8'))
+        data = req.args.get('data', '')
+        opener = urllib2.build_opener(urllib2.HTTPHandler())
+        chart_req = urllib2.Request('http://chart.apis.google.com/chart', data=data)
+        self.log.debug("Fetch chart, %r + data: %r" % (chart_req.get_method(), data))
+        chart = opener.open(chart_req)
         for header, value in chart.headers.items():
             req.send_header(header, value)
         req.write(chart.read())

[falkb]

Yessssssss! Your patch works well. Event that error logging mentioned in duplicate ticket #8686 is away now. Great work, mate! :-) This ticket can be closed now.

[osimons]

(In [10048]) EstimationToolsPlugin: Slight rework of server-side charts, switching to using POST requests to Google internally. References #5555.

[osimons]

Right, committed the patch switching to POST for server-side charts. Realistically this is the best that can be done for this, as we can't really redo the regular client-side requests based on <img/> tags. That would be way too involved.

So, I'm closing this as 'fixed'. Enable serverside_chart setting to overcome the 'HTTPError: HTTP Error 414: Request-URI Too Large' limitation.