Chart Topper

Chart Topper is an extension to the Sinatra DSL to allow you to quickly and dynamically create image based chart's and graphs.

# myapp.rb
require 'rubygems'
require 'sinatra'
require 'sinatra/chart_topper'

line "A graph of various fruit" do

    size "400x225"

    data "Apples",   [1, 2, 3, 4, 4, 3]
    data "Oranges",  [4, 8, 7, 9, 8, 9]       
    data "Watermelon", [2, 3, 1, 5, 6, 8]       
    data "Peaches", [9, 9, 10, 8, 7, 9]     

end

Install the software (for more info see the Installation section) and run with:

ruby mayapp.rb

View your graph at http://localhost:4567/a_graph_of_various_fruit.png

To install Chart Topper

sudo gem install chart-topper

Chart Topper is built around Gruff which is in turn built around ImageMagick and RMagick.

The quickest way to get the ImageMagick dependancy installed is to use MacPorts (OS X).

sudo port install imagemagick

Then install the gem dependancies as normal:

sudo gem install gruff rmagick    

Graph URL's are generated from the graph title. Non word characters are stripped, spaces become underscores and the whole thing is lowercased.

# Graph is addressable via /this_weeks_expenditures.png
pie "This week's expenditures" do
    ...
end

Various Gruff graph types are mapped to new Sinatra DSL methods, for a complete list see Sinatra::ChartTopper.GRAPH_TYPES

The basic rule is that any Gruff graph type can be generated via it's lowercased and underscore separated equivalent.

# Create a graph of type Gruff::AccumulatorBar
accumulator_bar "My accumulator bar graph" do
    ...
end

In order to make the DSL a bit nicer to use number of methods are delegated to the Gruff graph object. These can be found in Sinatra::ChartTopper.GRAPH_DELEGATIONS

dot "My dot graph" do
    # Delegated to Gruff::Base.data
    data "Tuesday", [2,4,6,8]
end

Direct access to the current Gruff graph object can be gained via the graph() method

spider "My spider chart" do
    graph.theme = {
        :colors => %w(orange purple green white red),
        :marker_color => 'blue',
        :background_colors => %w(black grey)
    }
end

You can pass through options to the graph methods. Currently the only available option is prefix though. This will add a prefix to the generated URL.

# /my/prefix/my_graph.png
bar "My Graph", :prefix => "/my/prefix/" do
	...
end

You can use the extension in modular style apps too ...

require 'sinatra/base'
require 'sinatra/chart_topper'

class MyApp < Sinatra::Base

  	register Sinatra::ChartTopper
	
	bar "My Graph" do
		...
	end
	
end

It's probably a good place to start, check out the examples directory.

License:

(GPLv3)

Copyright (C) 2009 Matt Haynes

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <www.gnu.org/licenses/>