Since RMagick seems to be broken on Win32 when using with Ruby 1.8.4 and Gruff is using RMagick to draw its pretty graphs, I had to go out and find an alternative chart library for use with Rails.
XML/SWF Charts
Fortunately I have run into this chart library a while back when doing php evelopment. It’s not really a php driven because the data input andconfiguration is in form of a XML file. To make it work with rails, all Ihad to do is translate the php function that generates the XML file to Ruby.
Well, after a few hours of playing around and experimenting with differentapproaches to the issue I think I have come up with a fairly easy way to get he charts working with rails.
Chart Sample
The above sample displays a sample of a working graph. After a few failed / ugly attempts, I settled for a class/controller hybrid that hopefully is easy to use. So with out further rambling, here is a step by step guide to get it to work:
1.Download the SWF Chart library and place it in the /public directory
2.Download the swfchart.rb class and place in the /lib directory
3.Download chart_controller and place it in the /controllers directory
With all the pieces in place , the last two components will be tied to your application directly. The data and options for the chart have to be set in a controller. For instance something like this should work:
@swf = SWFChart.new
session[:swfchart] = @swf
#set data headings
@swf.data_array = Array.new
@swf.data_array[0] = [nil]
@swf.data_array[1] = [”]
#get space count per category
for c in @current_show.ShowCategories
@swf.data_array[0] << c.name
@swf.data_array[1] << c.BaseSpaces.count
end
@swf.chart_type = "3d pie"
@swf.chart_rect = {:x => ‘150’,:width => ‘200’,:height => ‘125’}
@swf.legend_rect = {:x => 10, :y => 10, :width => 50, :height => 200}
And finally, the chart will be displayed from the view with code like this:
<%= @swf.insert_chart(:data_source => url_for(:controller => "/chart"), :width => "400", :height => "300") %>
Observant readers will have noticed that the whole chart data-setting and generation is encapsulated in the swfchart.rb class from the /lib directory. Unfortunately I don’t have much time to encapsulate this as a plugin, but perhaps somebody could take what I have and run with it…
06.12.06 – Edit
There have been a few issues reported by a few users while trying to get this up and running. In order to solve some of the more common mistakes, I have decided to create a sample project. Just download testapp.zip, unzip, run webrick and browse to http://localhost:3000/sample
08.02.06 – Edit
Version 0.1.14 of the SWFChart wrapper is done. Changes include a "plugin" like structure (still have to solve copying of the charts to the public directory before it becomes a true plugin) and minor bugfixes to xml generator method.
Installation:
Just download the swfchart.0.1.14.zip and unzip it to the root of your rails application. If you have a previous version installed , remove swfchart.rb from the lib directory and any require statements from your controllers.
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