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I am using the cfchart tag in ColdFusion 10 (zingcharts). The page containing the chart is receiving data via websocket and I am trying to pass some of this data to the chart at regular intervals with JavaScript, using: 

var x = data.number;
var handle = ColdFusion.Chart.getChartHandle();
handle.exec('mychart', 'appendseriesvalues', '{"plotindex": 0, "values": [x]}');

The above code works fine if I enter an actual number instead of x, for example "values": [1.1] works fine. However if I try and pass in a number by way of a dynamic variable, it does not work and throws this error:

SyntaxError: JSON.parse: unexpected character

I was wondering if anyone knows how to accomplish this?

Peter Boughton
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AlanJames
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  • I would suggest not using `cfchart` in ColdFusion 10. I have played around quite a bit with this functionality, and I find it is actually easier to use ZingCharts directly, rather than use the implementation in ColdFusion 10 - especially when it comes to formatting and styling the charts. – Scott Stroz Sep 01 '13 at 12:39

2 Answers2

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Following on from @PeterBoughton's answer/comment, the ZingCharts API is really well documented. So, yes, you can pass an object rather than a JSON representation of one (based on the code example on that page). That would be a preferable approach.

Having messed around with <cfchart> and ZingCharts directly... I find it's much easier to do the latter, and remove <cfchart> from the equation altogether. There's little gain in becoming an expert in <cfchart> (it's not a marketable skill), whereas being comfortable using Javascript libraries directly (if not specifically ZingCharts) is a better tool to have in one's belt.

Adam Cameron
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You're passing a JSON string to handle.exec, which is turned into a JS object in a different place to where your x variable is defined, and thus causing the error.

Instead, let x be resolved as part of the string and it should work:

handle.exec( ... , '{"plotindex": 0, "values": ['+x+']}');
Peter Boughton
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  • Excellent, thanks very much for that Peter !! I was pulling my hair out...very much appreciated. – AlanJames Aug 30 '13 at 11:36
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    No problem. It _might_ be possible to pass in an object directly (not a string), then you could do `handle.exec( ... , {"plotindex": 0, "values": [x]} )` but I don't know if cfchart works like that or not. – Peter Boughton Aug 30 '13 at 11:39