rails-google-visualization-plugin: A Ruby repository from mwarnock

GoogleVisualization
===================

This plugin currently covers the following visualizations: MotionChart, Annotated Time Line, LineChart, PieChart, ColumnChart and BarChart.

Max Warnock (http://github.com/mwarnock) wrote the original code which I've altered slightly so that the plugin implements a few extra visualization types.

Installation
============
If you are unfamiliar with how to install rails plugins you’ll want to look here (http://nubyonrails.com/articles/the-complete-guide-to-rails-plugins-part-i) for guidance. To install it run this from the root of your rails app:

ruby script/plugins install git://github.com/geirfreysson/rails-google-visualization-plugin.git
mv vendor/plugins/rails/rails-google-visualization-plugin vendor/plugins/google_visualization #It needs to be renamed for the sake of rails auto loading

Usage
=====
First of all, your app's header has to include the necessary js files. This can be done either by adding

-- application.html.erb (layout)
<%= setup_google_visualizations('linechart','barchart') %>

into your layout or by adding the following into the layout and the view that will render your graphs.


-- application.html.erb (layout)
<%= yield :head %>

-- graph.html.erb (view with charts)
<% content_for(:head) do %>
  <%= setup_google_visualizations('linechart', 'annotatedtimeline', 'piechart') %>
<% end %>

Not that you pass the name of the visualizations you are using as parameters to the setup function, according to what goole calls them (see the google visualization docs).

I prefer the second method so that the js is only fetched if the user goes to whatever parts of the app has charts, but if this is every other page, you might as well include it in the layout.

Once the js files have been included, this is an example of code to put into your view to create a chart:

<% dates = [Date.new(2009,1,1),Date.new(2009,2,1),Date.new(2009,3,1),Date.new(2009,4,1)] %>
<% line1= [1,2,3,4] %>
<% line2= [2,3,4,5] %>
<% line3= [1,1,4,5] %>

<% line_chart_for @dates, :width=>1000, :height=>400, :min=>4, :axis_color=>'#cccc',
                            :axis_font_size=>'12', :axis_fontcolor=>'#cccccc',
                            :legend_font_size=>'12', :title_font_size=>'12',
                            :colors=>["#216DE1","#D0221B","#8BC026"] do |chart| %>
  <% chart.add_line("first line",line1,:value=>:to_f) %>
  <% chart.add_line("second line",line2,:value=>:to_f) %>
  <% chart.add_line("third line",line3,:value=>:to_f) %>
<% end %>

Note that for each chart you can pass any options that are supported by whichever Google visualization you are
using. Supply the options with the ruby underscore convention and they are converted to camelCase.

The pie charts take slightly different data in the sense that for each pie, there is only one
'column'.

Example:

<% @categories = ["Blood", "Sweat", "Tears"] %>
<% line1= [4,3,2] %>

<% pie_chart_for @dates, :width=>400, :height=>400, :title=>'What it takes' do |chart| %>
  <% chart.add_line("the line",line1,:value=>:to_i) %>
<% end %>

Finally, note that PieChart, LineChart, BarChart and ColumnChart can all take strings
instead of dates for the value of their x-axis, but AnnotatedTimeLine expects dates.


Additional Information
======================

For more information see the rails-google-visualization-plugin wiki on github at http://wiki.github.com/mwarnock/rails-google-visualization-plugin

Copyright (c) 2008 Max Warnock, released under the GNU Public License v3