Tag: Ruby on Rails applications

How To Generate Barcode Using Barby Gem In Rails 2.3.8

Posted on by Jay

A barcode is a series of vertical black lines with white spaces in between. This series of lines and spaces can be read by a device that can decode them. This would be a barcode reader.

In Ruby on Rails there is a gem called “barby” which generates the barcode with various format.

Here is an example to create barcode using barby & Rails 2.3.8.

Step#1

Include the barby gems in your config/environment.rb file

config.gem'barby'
config.gem 'barby-chunky_png'
config.gem 'png''RubyInline'

Install the gems by running the commandrake gems:install. Restart the Rails server.

You might face problem to start the server after the gems installed.Comment out the gems “png” & “RubyInline” in the “config/environment.rb” to get the server started.

Step#2

Create a folder named “Barcodes” to store the barcode images in your “Public” folder.

Step#3

Add the below lines of code in your controller

require'barby'
'barby/outputter/png_outputter'

Step#4

The following method will generate the barcode images and store in the “/public/Barcodes” path. Place this method inside the controller.

The “symbology” is the format in which the barcode will be generated. Default is “Code128B”, If you want to generate in different format you can set the “symbology” according to it.

def generate_barcodes(data) # check to see if we don't already have this barcode image uri = CGI.escape(symbology) + '_' + CGI.escape(data) + '.jpg' fname = RAILS_ROOT + '/public/Barcodes/' + uri #fname = '/var/www/html/arc_cloud/arcdevelopment/' + uri
 
# if the barcode image doesn't already exist then generate and save it
if ! File.exists?(fname)
 
str = 'Barby::'+symbology+'.new("'+data+'")'
 
begin
barcode = eval str
rescue Exception => exc
barcode = Barby::Code128B.new(data) # fall back to Code128 type B
end
 
File.open(fname, 'w') do |f|
f.write barcode.to_jpg
end
 
end
uri
end

Step#5

Following lines of code will call to generate your dynamic barcode
generate_barcodes(@item_id)

Step#6

To show the Barcode images call the following lines of code

<img src="/Barcodes/<%= @job_info.job_number %>.jpg" >

How to use Nested Attributes in Rails 3 Forms

Posted on by Jay

For example, say we want to add multiple addresses(attributes) having many fields inside a create/edit employee form

Step# 1

  •         Create a model named Employee
  •         Create another model named Address
  •         Add the following relationship in Employee model
class Employee < ActiveRecord::Base
has_many :addresses, :dependent => :destroy
accepts_nested_attributes_for :addresses, :reject_if => lambda { |a| a[:city].blank? }
end
  •    Nested attribute form rejects if the city field of the address is blank

Step# 2

  •        In Employees controller add the following in the “new” action
def new
@employee = Employee.new
@employee.addresses << Address.new
end

Step# 3

  •         In the view file add the following inside the form attribute
<%= form_for @employee, :html => { :multipart => true, :id => 'new-employee' } do |f|
<%= f.label :name, 'Name' %>
<%= f.text_field :name %>
 
<% end %>

Ruby Rails Development Sphere & Associated Myths

Posted on by Jay

Ruby on Rails development is fast changing the norms of web development across the globe.

Companies around the world are fast catching up with this magical web development framework for exploring and executing its true potentials; thereby serving their clients with really cost-effective, quick and dynamic Ruby on Rails Applications.

Ruby developers and Rails developers are becoming the most sought after skilled professionals, for Software companies to hunt for.

Ruby on Rails, being an Open Source tool, coupled with fast development life cycle, requires much less resources in terms of Programmers and man-hours; which results in the service provider and client being the ultimate beneficiaries.

Silicon Valley based leading Software firm, Andolasoft Inc. is a formidable force to reckon with as far as Ruby on Rails development is concerned.

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With a vast pool of Programmers as well as Domain Leads, this fairly young Enterprise has carved out many Social Networking Sites, Social Media Marketing web apps.

Andolasoft services include but not limited to RoR Development, RoR Application Migration, Social Media Integration, System Administration, Redesigning of Existing Apps, Performance Improvement Related Tasks and Rescue Support.

Irrespective of all its popularity, RoR also has few myths related to it.

Applications can be built hundreds of thousands times faster than other technologies: The fact is Rails doesn’t write the code automatically.

It just lets the developers work easy by managing certain functionalities; thereby allowing them to focus on other crucial modules.

It also manages the laborious part of lifting of user interactive modules. Having said that, such myths reflects a wrong opinion upon customers, whose expectations sometimes become too high for the service providers.

Even Non-programmers can build web applications: This is by far the silliest perception about Rails development. Although the simplicity of this framework and clean syntax of ruby language assist in quick development, but still experience is required as far as writing code is concerned.

Rails developers do need to write new and unique code, apart from using the Rails conventions on top a comprehensive web development framework.