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.

Example PieChart

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' } %>

Installation

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

Usage

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

google_chart

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

Argument	Description
type	The type of chart (e.g. :line, see below)
headers	The column data. Can be column name or object
data	A 2-D array of data rows. headers and data combined are passed to arrayToDataTable()
opts	Options passed to chart.draw()
chart_id	The HTML id attribute to use for the chart
parent_tag	The tag used to wrap the child tags

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

Chart Types

Types
:annotation
:area
:bubble
:bar
:calendar
:candlestick
:column
:combo
:gantt
:gauge
:geochart
:histogram
:line
:map
:orgchart
:pie
:snakey
:scatter
:stepped
:table
:timeline
:treemap
:word

License

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