Using GRUFF with Ruby on Rails
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
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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
