Simple GCharts

Create Google Charts in your views using ruby, with no Javascript required. This library will serialize your data andautomatically load any required charts packages, and render your charts for you. Requires jQuery.

class ActivitiesController < ActionController::Base
  def graphs
    @activities = {
      'Work' => 11,
      'Eat' => 2,
      'Commute' => 2,
      'Watch TV' => 2,
      'Sleep' => 7
    }
  end
end

# views/activities/graphs.html.erb
<%= google_chart :pie, ['Task', 'Hours per Day'], @activities.map { |k,v| [k, v] }, { title: 'My Daily Activities' } %>

Add this line to your application's Gemfile:

gem 'simple-gcharts'

And then execute:

$ bundle

Or install it yourself as:

$ gem install simple-gcharts

Add script to application.js (or appropriate page)

//= require jquery
//= require simple-gcharts

See the Google Charts Documentation for chart type descriptions and options.

def google_chart type, headers, data, opts={}, chart_id="chart-#{SecureRandom.hex(10)}", parent_tag=:div

Ruby can't make Javascript date objects, but fortunately Google Charts supports an alternate syntax for date and time datatypes. You can use chart_date_format to convert DateTime objects to the proper format.

def chart_date_format(datetime, time=false)
  if time
    datetime.strftime "Date(%Y, %m, %d, %H, %M, %S)"
  else
    datetime.strftime "Date(%Y, %m, %d)"
  end
end

The gem is available as open source under the terms of the MIT License.