Andrew Schwabe's Blog - charting

Presentation Files from CFUnited Express New York on April 20 2009

Tue, 21 Apr 2009 14:31:00 -0400

Here are the presentation files I used during my talk in NYC yesterday. The unexpected "intermission" has been omitted from the Powerpoint file :) http://www.schwabe.net/2009%20Charting_with_CF_Flex.zip Thanks again to Liz, Nafisa, and the others from CF United, the speakers and PACE University for making this a great event! Looking forward to seeing you all in August at CF United!

I have been invited to speak at CF United Express in NYC on 4/20/09

Fri, 20 Mar 2009 19:50:00 -0400

Thanks to Liz Frederick and the CF United team for their invitation! I will be presenting on "Charting with ColdFusion and Flex" and will go through step by step on how to build charts using Flex's charting package. In addition, we will go over how to build a reusable chart project where you can use the Flex/Ajax bridge to push chart data into your Flex app using Javascript/JSON/etc. Should be a good time, come on out! The details are online here: http://express.cfunited.com/go/newyork/2009/ Don't forget that I will also be speaking at CFUnited August 12-15 2009 in Leesburg, VA about integrating Flex with Google App Engine (GAE). Details are at www.cfunited.com.

CF United 2008 Presentation Files

Thu, 19 Jun 2008 02:00:00 -0400

Here are the presentation files and sample flex apps from my presentation on "Charting with CF and Flex" on Friday June 20, 2008.

RIA328_Charting_with_CF_and_Flex.zip (5.5M)

Google Chart API

Fri, 07 Dec 2007 02:00:00 -0400

From the incredible minds at Google :)

http://code.google.com/apis/chart/

This impressive little library lets you generate PNG chart files from a single URL request string. Since people typically need to pass lots and lots of data for charting, they came up with a really creative way to compress the values, and provide a javascript snippet for automating the process.

So the nifty chart you see to the right is a "hello world" app using their API. It ultimately comes down to a simple URL request of:

http://chart.apis.google.com/chart?cht=p3&chd=s:hW&chs=250x100&chl=Hello|World

Quite impressive and easy to use!

While this doesn't provide the stellar interactivity and depth of integration that Flex charts do, it certainly provides a way to do nice looking charts with a quick turn-around.

According to their docs, you can freely use this so long as you don't regularly exceed the 50,000 hits per day limit at which point they may block you. I think most of us will not be hitting it quite this much.

Some samples:

Using JFreeChart with ColdFusion

Fri, 22 Jul 2005 02:00:00 -0400

This was originally posted in Christian Cantrell's blog.

Well, your post just helped me figure out a long time nagging problem. I have been working on a CF wrapper for JFreeChart to generate on-the-fly charts, and have been stumped with corrupted output, until I saw your fix about the double getResponse() method calls. With that change, all works great!

For those who don't understand WHY you might need to do this, here is sampe code that creates a bar chart on-the-fly (no caching on the file system) and outputs directly to the browser a JPEG image (or a PNG with incredible quality!):

barDataset = CreateObject("java", "org.jfree.data.category.DefaultCategoryDataset");
Randomize(numberformat(timeformat(now(),"ss")));
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2001", "Q1");
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2001", "Q2");
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2001", "Q3");
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2001", "Q4");
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2002", "Q1");
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2002", "Q2");
rval = int(randrange(1,500));
barDataset.setValue(numberformat(rval), "2002", "Q3");
rval = int(randrange(1,500)); barDataset.setValue(numberformat(rval), "2002", "Q4");

chart = CreateObject("java", "org.jfree.chart.JFreeChart");
chartfactory = CreateObject("java", "org.jfree.chart.ChartFactory");
chartorient = CreateObject("java", "org.jfree.chart.plot.PlotOrientation");
chartutil = CreateObject("java", "org.jfree.chart.ChartUtilities");

chart = chartfactory.createBarChart3D ("Sample Bar Chart", "Category", "Value", barDataset, chartorient.VERTICAL, true, true, true);

response = getPageContext().getResponse().getResponse();
response.setContentType("image/jpeg");

chartutil.writeChartAsJPEG(response.getOutputStream(),
   100, // jpeg quality 0-100
   chart, // chart object
   500, // width
   300); // height

response.flush();
response.close();

If anybody else needs help with the above code, email me.

cheers