Using GRUFF with Ruby on Rails

Posted May 1st, 2008 by manmeet

Gruff is a RoR plugin to generate On-The-Fly graphs within the Web Application. Developed by Geoffrey Grosenbach you can find the Plugin Home Page at http://nubyonrails.com/pages/gruff

The API documentation can be found at http://gruff.rubyforge.org/

Example Graphs

Installation
Simple type in the following command to install Gruff 




sudo gem install gruff 




To use it in a Rails project you can also  unpack the gem into the vendor/plugins directory and add the following line to  environment.rb located in the config directory




require 'gruff'




 




Sample Basic Graph








g = Gruff::Line.new #Define a New Graph

g.title = "My Graph" #Title for the Graph




g.data("Apples", [1, 2, 3, 4, 4, 3]) #Graph Data

g.data("Oranges", [4, 8, 7, 9, 8, 9])

g.data("Watermelon", [2, 3, 1, 5, 6, 8])

g.data("Peaches", [9, 9, 10, 8, 7, 9])




g.labels = {0 => '2003', 2 => '2004', 4 => '2005'} #Labels for Each of the Graph




g.write('my_fruity_graph.png')







The about graph will write a graph to the file to my_fruity_graph.png. In case you want to generate graphs dynamically without writing to a file you can do so through the following




send_data(g.to_blob, :disposition => 'inline', :type => 'image/png', :filename => "arbitaryfilename.png")




The above line simlple gets the graph data and displays it with an image header. I have used g.to_blob to repeatedly updates graphs on Reports.




 




SQL Query to Retrieve records grouped by dates





I have used the following query to retrieve all the graph data ordered by Date. After retrieving the data to an array I wrote a function which fills in empty data for the days that dont have data. The query does an excellent job of retrieving a lot of data within a given date range. I used the query for a Banner Management Tool to get Clicks and Views Statistics for a period of time.







SELECT COUNT( * ) AS data, DATE_FORMAT( created_at, '%Y-%m-%d' ) AS

day FROM `adlogs`

WHERE CLICK = " + clicks.to_s +

" AND BANNER_ID = " + id.to_s + 

" AND created_at > '" + qstart.to_s + "'

AND created_at < '" + qend.to_s + "'

GROUP BY DATE_FORMAT( created_at, '%Y %m %d' ) 

ORDER BY DATE_FORMAT( created_at, '%Y %m %d' ) ASC