RoR Guide & Solutions

Generate PDF using rails view with PDFKit gem

2018-03-23T13:18:00.001+05:30

PDFKit gem is used to generate PDF files using HTML from rails view and style code. We will use this gem to generate PDF for our Rails5 application.

Following are the steps where we need to change in code:

Step1:-

Open a gemfile and install following gems

gem 'pdfkit'

gem 'render_anywhere'

Then run bundle install.

Step 2:-

Add following line in your config/application.rb

config.middleware.use PDFKit::Middleware, :print_media_type => true

Step3 :-

Add following line in your layout/application.html.erb

<%= stylesheet_link_tag 'application', :media => "all" %>

Step 4:-

Give the link of pdf on view page so that it will convert the page in form pdf format. Add the following link your orders/show.html.erb

<%= link_to "Download PDF",user_path(@user, format: "pdf") %></p>

Step5 :-

If you want to convert some specific HTML data in pdf format, do following:

require "pdfkit"

kit = PDFKit.new(<<-HTML)

HTML CODE

HTML

kit.to_file("html.pdf")

Image upload using paperclip gem in rails5

2017-11-01T12:35:00.000+05:30

Image uploading is an important feature in web application. Here are few steps to enable image uploading function using “Paperclip gem”:

Step-1:

Paperclip requires the installation of ImageMagick on your Mac machine:

brew install imagemagick

Step-2:

Open gemfile and add gem:

gem 'paperclip'

then run bundle install

Step-3:

After adding gem add the image column in your table, here users table. Run

command:

rails generate migration add_image_to_users

This will create new migration in db/migrate then run migration

Step-4:

We also need to add validation for your image attribute. Add following code in your model 'user.rb'

has_attached_file :img, styles: { medium: "300x300>", thumb: "100x100>" }, default_url: "/images/:style/missing.png"

validates_attachment_content_type :img, content_type: /\Aimage\/.*\z/

Step-5:

After that you need to edit in your users new form and edit form with following HTML code

app/views/users/new.html.erb

app/views/users/edit.html.erb

<%= f.file_field :image %>

</div>

Step-6:

After submitting the form if you want to show the image you need to add following code to the app/views/users/show.html.erb

<p>

<strong>Image:</strong>

<%= image_tag @user.image %>

</p>

Sending email in Rails5 using Mailtrap

2017-03-01T12:52:00.000+05:30

Email Functionality:-

In our rails application we want to create email functionality so that rails application will send an email to the user when a new user is created.

Following step will show how to send email through ActionMailer, ActionMailer Preview and third party email provider.

Step-1 :-

In your rails app on terminal start with following command.

$ rails g mailer example_mailer

this will create mailer folder in our application.

Step-2 :-

Then go for the following path

app/mailers/example_mailer.rb

Add following code

class ExampleMailer < ActionMailer::Base

default from: "from@example.com"

end

It will set a sender’s email address by default

Step-3 :-

Create a sample_email method it will take the parameter and send email to email address of user.

class ExampleMailer < ActionMailer::Base

default from: "from@example.com"

def sample_email(user)

@user = user mail(to: @user.email, subject: 'Sample Email')

end

Step-4 :-

Now we will write a mail we want to send to our user and this can be done by adding sample_email.html.erb file in views

so create sample_email.html.erb to app/views/example_mailer/sample_email.html.erb

and write following code.

<!DOCTYPE html>

<html>

<head>

</head>

<body>

<p> Sample mail sent using smtp. </p>

</body>

</html>

Step-5:-

We also need create text part for this email.

So create sample_email.text.erb in your app/views/example_mailer and add following code:

Hi <%= @user.name %>

Sample mail sent using smtp.

Step-6:-

By default rails tries to send emails via SMTP. We will provide SMTP configuration in environment settings/config/environments/production.rb. Add following code using your any mailtrap address

config.action_mailer.smtp_settings = {

:user_name => ‘<username>,

:password => '<pwd>',

:address => 'smtp.mailtrap.io',

:domain => 'smtp.mailtrap.io',

:port => '2525',

:authentication => :cram_md5

}

Step-7 :-

Now edit the UsersController to trigger the event that will send an email to a user.

We just need to add “ExampleMailer.sample_email(@user).deliver”

line to the create method in app/controllers/users_controller.rb.

def create

@user = User.new(user_params)

respond_to do |format|

if @user.save

ExampleMailer.sample_email(@user).deliver

format.html { redirect_to @user, notice: 'User was successfully created.' }

format.json { render :show, status: :created, location: @user }

else

format.html { render :new }

format.json { render json: @user.errors, status: :unprocessable_entity }

end

After doing all this step restart your server and create any new user. User will receive welcome mail in mail account.

Solved: Error “bash: scp: command not found” when using scp command

2016-01-30T11:42:00.000+05:30

I am doing scp from my linux system to one of the newly installed Centos system. When I run the scp command and enter password, I get following errors:

ritesh@rorguide:~/projects$ scp -r rorguide root@202.89.64.50:/root/code
root@202.89.64.50's password:
bash: scp: command not found
lost connection

Solution:
I found the solution on
http://stackoverflow.com/questions/17131048/error-when-using-scp-command-bash-scp-command-not-found

which states scp command should be available on both server - both on the client and on the server.

I ran the command "yum -y install openssh-clients" on Centos. After successfully installing the scp I was able to scp files on remote system.

Online Shopping Store India - Reservedeal: Let’s Say Our Final Goodbye to Winter And Welcome ...

2016-01-17T08:17:00.001+05:30

Online Shopping Store India - Reservedeal: Let’s Say Our Final Goodbye to Winter And Welcome ...: New Year has just started and time for festivity has commenced. We welcome the New Year with immense prosperity and happiness, harvesting the success, health and wisdom. Winters are at the verge of bidding us goodbye for the next year to come where spring is just on the way. A time of harvest celebrated with joy and pompous, sweetening it up with authentic ingredients like til, gul, popcorns, mungfali and many other sweet candies. A wave of festive season spreads across India in form of Lohri in Punjab, Pongal in South India, Uttarayan in Gujarat, Makar Sankranti in Maharashtra and with many other names. ...

Solution to remove Warning "Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true"

2014-02-04T20:55:00.000+05:30

While working on Rails 4 application, getting following lines in application log file:

[2014-02-04 20:31:12] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true
[2014-02-04 20:31:12] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true
[2014-02-04 20:31:12] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true
[2014-02-04 20:31:12] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Solution:
Taken from "http://stackoverflow.com/questions/9612618/warn-could-not-determine-content-length-of-response-body-set-content-length-of"

This is a problem of Webrick. you can use "Thin" instead.

Add this to Gemfile

gem 'thin'

then rails s will use thin instead of Webrick, and the warn will disappear.

Solution to turn off Rails asset pipeline log in Rails 4 development log file

2014-02-04T20:46:00.000+05:30

While working on one of the application created in Rails4, I was annoyed by the way Rails asset was writing in application log file, debugging was turning out to be bit difficult. Here is how the log was looking like:

Started GET "/assets/application.js?body=1" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Started GET "/assets/facebook32x32.png" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Started GET "/assets/youtube32x32.png" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Started GET "/assets/googleplus.png" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Started GET "/assets/twitter-old.png" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Started GET "/assets/linkedin32x32.png" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Started GET "/assets/banner5.jpeg" for 127.0.0.1 at 2014-02-04 20:20:53 +0530
[2014-02-04 20:20:53] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

Here is the solution which I implemented to turn off assets pipeline log:

I added 'quiet_assets' gem in Gemfile and then run bundle install:

gem 'quiet_assets', :group => :development

To re-enable the logging of the asset pipeline messages, place the following in yourconfig/application.rb file:

config.quiet_assets = false

'ExecJS::RuntimeUnavailable' error after creating new Rails4 application

2013-09-09T00:27:00.000+05:30

Create new rails4 application, run command: rails new interview -d mysql
It will automatically run bundle install.
Browse to interview folder and try to start rails server by command, 'rails s'.
It will give error:

ritesh@ritesh-ThinkPad-L420:~/projects/interview$ rails s
/home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/execjs-2.0.1/lib/execjs/runtimes.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/execjs-2.0.1/lib/execjs.rb:5:in `<module:ExecJS>'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/execjs-2.0.1/lib/execjs.rb:4:in `<top (required)>'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/uglifier-2.2.1/lib/uglifier.rb:3:in `require'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/uglifier-2.2.1/lib/uglifier.rb:3:in `<top (required)>'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429@global/gems/bundler-1.3.5/lib/bundler.rb:132:in `require'
    from /home/ritesh/projects/interview/config/application.rb:7:in `<top (required)>'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/railties-4.0.0/lib/rails/commands.rb:76:in `require'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/railties-4.0.0/lib/rails/commands.rb:76:in `block in <top (required)>'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/railties-4.0.0/lib/rails/commands.rb:73:in `tap'
    from /home/ritesh/.rvm/gems/ruby-1.9.3-p429/gems/railties-4.0.0/lib/rails/commands.rb:73:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

Solution:
To fix this issue, edit Gemfile and comment out the line:
gem 'therubyracer', platforms: :ruby
After this run bundle install and you can start rails server.

Although I was able to fix it, but I am not sure why 'therubyracer' gem in Gemfile is commented ???

Where to start on Rails4 : Links, Resources, Tutorials, Tips, References

2013-09-08T21:18:00.000+05:30

Tutorials:
http://net.tutsplus.com/tutorials/ruby/digging-into-rails-4/
http://edgeguides.rubyonrails.org/
http://ruby.railstutorial.org/ruby-on-rails-tutorial-book
https://blog.engineyard.com/2013/new-in-rails-4

Two most important links:
http://blog.wyeworks.com/2012/11/13/rails-4-compilation-links/
http://blog.remarkablelabs.com/2012/11/rails-4-countdown-to-2013

Videos:
http://railscasts.com/episodes/400-what-s-new-in-rails-4
http://railscasts.com/?tag_id=38&view=list

Upgrading to Rails4:
http://railscasts.com/episodes/415-upgrading-to-rails-4
http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html

Features:
Many features can be found on rails-3.1 features
Asset Pipeline : http://edgeguides.rubyonrails.org/asset_pipeline.html

Turbolinks : http://railscasts.com/episodes/390-turbolinks

Russian Doll Caching and Cache Digests : http://blog.remarkablelabs.com/2012/12/russian-doll-caching-cache-digests-rails-4-countdown-to-2013

Multiple ways to import your data in ror

2012-11-17T00:21:00.002+05:30

1. Importing the csv data from a specific location through Rake Task
URL of that blog - http://rorguide.blogspot.in/2012/11/importing-csv-data-from-specific.html

2. Importing the csv data by browsing and uploading csv from application screen
URL of that blog - http://rorguide.blogspot.in/2012/11/importing-csv-data-by-browsing-and.html

Importing the csv data by browsing and uploading csv from application screen

2012-11-17T00:14:00.000+05:30

Importing the csv data by browsing and uploading csv from application screen

Given below code will be placed in view which will allow user to browse file to upload from view. Notice the code
:html => { :multipart => true }
which is mandatory for uploading file.

<% form_for :dump, :url=>{:controller=>"imports", :action=>"csv_import_eqdata2"}, :html => { :multipart => true } do |f| -%>
<table border=1>
<tr>
<td>
<label for="dump_file">
Select a EQ Data CSV File2 :
</label>
</td>
<td >
<%= f.file_field :file -%>
</td>

<td colspan='2'>
<%= submit_tag 'Submit' -%>
</td>
</tr>
</table>
<% end -%>

==================
After upload when user will hit submit button, it will call imports controller, csv_import_eqdata2 action. Here are the codes which will be written in controller:

def csv_import_eqdata2
@parsed_file=CSV::Reader.parse(params[:dump][:file])
n=0

@parsed_file.each do |row|

rsymbol = row[0].strip if !row[0].blank?
rseries = row[1]
rtottrdqty = row[2]
rtottrdval = row[3]

@eqrawdatas = Eqrawdata.find(:all, :conditions => ["symbol='#{rsymbol}' and series ='#{rseries}' and tottrdqty ='#{rtottrdqty}' and tottrdval ='#{rtottrdval}' and deleted_at is null"])

presentinlotsize = Lotsizedata.find(:first, :conditions =>["symbol='#{rsymbol}' "])

#Accept only those records whose series is EQ only
if @eqrawdatas.blank? && !rsymbol.blank? && !rseries.blank? && (rseries == "symbol" or rseries == "EQ") && !presentinlotsize.blank?
c=Eqrawdata.new
c.symbol= rsymbol
c.series=rseries
c.tottrdqty = rtottrdqty
c.tottrdval= rtottrdval

if c.save
n=n+1
GC.start if n%50==0
end
flash.now[:message]="CSV Import Successful, #{n} new records added to data base"
end
end
return redirect_to(eqdatalist_url)
end

Importing the csv data from a specific location through Rake Task

2012-11-17T00:01:00.001+05:30

1. Importing the csv data from a specific location through Rake Task:

We can import data from csv file which is placed in csv folder in our Rails application root directory. Here we checks that csv file name should start with eq2 and ends with .csv, only these csv files should be picked to parse. All such csv files will be parsed. Place the given below code in "lib/tasks" folder as a rake task and run to import data.

Here are code details:

namespace :import do

desc 'import csv files of eq2'
task :eq2 => :environment do
root = Rails.root.to_s
require 'csv'

#importing eq2 csv files where name starting from eq2 and ending with csv
eq_files = Dir.glob("#{root}/csv/eq2*.csv")
puts "Found eq2 csv file named #{eq_files}"

if !eq_files.blank?
eq_files.each do |eq_file|
puts "eq1 file is not blank #{eq_file}"

@parsed_file = CSV::Reader.parse(File.open(eq_file, "rb"))
n = 0
@parsed_file.each_with_index do |row, i|
next if i == 0 || i == 1
break if row[2].blank?

rsymbol = row[2].strip if !row[0].blank?
rseries = row[3]

presentinmaster = Masterdata.find(:first, :conditions =>["nse_symbol='#{rsymbol}' "])

#Accept only those records which fulfill following conditions
if !presentinmaster.blank? !rsymbol.blank? && !rseries.blank? && (rseries == "symbol" or rseries == "EQ")
c=Eqmasterdata.new
c.symbol= rsymbol
c.series=rseries
c.masterdatas_id = presentinmaster.id
if c.save
puts "CSV Import Successful, #{n} new records added to data base"
n=n+1
GC.start if n%50==0
else
puts "EQ2 could not be save, error is #{c.errors}"
#else writing error in different table
AllError.create(:error_of => 'EQ2', :error_detail => c.errors, :error_summary => "Data not saved")
end
end

end
end
end
end
end

Multiple ways to export your data in ruby on rails

2012-11-16T23:44:00.001+05:30

1. Prompting and letting user save csv in a particular folder:

Export excel from Rails application - User gets a link on view and when user clicks on that link a prompt comes asking user to save the exported excel on clients computer at desired location. In this case, you can create excel view and perform view formatting as we do with html page.

URL of blog - prompting-and-letting-user-save-csv-in-particular-folder

2. Saving the csv at a particular pre-defined folder:

Export csv at a particular pre-defined folder specified in rails application: User gets a link on view and when user clicks on that link user is not asked about the location for saving the csv, csv is exported and saved at pre-defined location. In this case, you cannot create excel view.

URL of blog - export-csv-at-particular-pre-defined-folder

CSV reader syntax change in Ruby 1.8.7 and Ruby 1.9.2

2012-11-16T22:14:00.000+05:30

The way CSV file is opened in Ruby 1.8.7 and in Ruby 1.9.2 are different, here are the syntax:

@parsed_file = CSV::Reader.parse(File.open(restaurant_file, "rb"))
when running from ruby 1.8.7

new
@parsed_file = CSV.read(restaurant_file)
when running from ruby 1.9.2

Fixed error "_gedit_app_get_window_in_viewport: assertion `GEDIT_IS_WINDOW (window)' failed"

2012-06-02T19:13:00.001+05:30

On Ubuntu when I try to open a file through gedit, I get following error:

"** (gedit:2679): CRITICAL **: _gedit_app_get_window_in_viewport: assertion `GEDIT_IS_WINDOW (window)' failed"

To fix the problem first remove gedit by command:
- sudo apt-get remove gedit

Then install gedit again:
- sudo apt-get install gedit

Export csv at a particular pre-defined folder in rails application

2012-02-04T21:57:00.000+05:30

Export excel from Rails application - User gets a link on view and when user clicks on that link user is not asked about the location for saving the csv, csv is exported and saved at pre-defined location. In this case, you cannot create excel view.
Saving the csv at a particular pre-defined folder
Code snippets:

1. Add action on 'eqrawdatas' controller:
def export_list
require 'csv'
symboldetails = Masterdata.find(:all)
config = read_config_exp

    outfile = File.open(File.join(config['event_export_path'],"export_data.csv"), "w")
      CSV::Writer.generate(outfile) do |csv|
      csv << Array["Uniq Symbol", "Symbol", "Data Date" ]
      symboldetails.each do |symboldetail|
        arr = []
    arr = Array[symboldetail.uniqsymbol, symboldetail.symbol, symboldetail.data_date.strftime("%b %d, %Y") ]
        csv << arr
      end
    end
    outfile.close
return redirect_to :back
end

2. In the same controller, add a private method
private
#read the config file

def read_config_exp
    config_file = File.open("#{RAILS_ROOT}/misc/export_event.yml")
    erb = ERB.new(config_file.read)
    all_configs = YAML.load(erb.result(binding))
    dir = all_configs["All"]["event_export_path"]
    Dir.mkdir(dir) unless File.exists?(dir)
    all_configs['All']
end

3. Create export_event.yml file in misc folder inside rails application
In rails application misc folder, create export_event.yml file. In this file it will export the csv data in C:\exported_csv folder:
All:
event_export_path: C:\exported_csv

4. Add link on view:
<%= link_to("Export EQ Date Data List", :controller => :eqrawdatas, :action => :export_list) %>

Prompting and letting user save csv in a desired folder

2012-02-04T21:05:00.000+05:30

Export excel from Rails application - User gets a link on view and when user clicks on that link a prompt comes asking user to save the exported excel on clients computer at desired location. In this case, you can create excel view and perform view formatting as we do with html page.
Prompting and letting user save csv in a desired folder:
Code snippets:

1. Add in routes:
map.fumasterdatalist 'chart/fumasterexcel', :controller => "chart", :action => "fumaster_excel"

2. Add link on view:
   <%= link_to "Export FU List as Excel", {:controller=> "chart", :action=> "fumaster_excel"} %>

3. Add action on controller
def fumaster_excel
      @oprawdatas= Expdatedata.find(:all, :order=> "exp_date asc")
      headers['Content-Type'] = "application/vnd.ms-excel"
      headers['Content-Disposition'] = 'attachment; filename="fuexpreport.xls"'
      headers['Cache-Control'] = ''
      render(:layout=>false)
    end

4. Create a view page which will be exported in excel:

<table "border=1px" cellpadding="2" style="margin: 20px 40px">
<tr>
   <th>Sl. No.</th>
   <th>ID</th>
   <th>Instrument</th>
    <th>Symbol</th>
    <th>Created_At   </th>
</tr>

<% i = 0 %>
<% @oprawdatas.each do |import| %>
<tr>
<td><%=i = i + 1 %></td>
<td><%=h import.id %></td>
    <td><%=h import.instrument %></td>
    <td><%=h import.symbol %></td>
    <td><%=h import.created_at.strftime("%b %d, %Y") %></td>
    <td><%= link_to 'Destroy', {:controller=> "oprawdatas", :action=> "destroy", :id=> import.id}, :confirm => 'Are you sure you want to delete the record?' %></td>
</tr>
<% end %>
</table>

"src/rbae.c:13:27: fatal error: Carbon/Carbon.h: No such file or directory" while installing rb-appscript (0.6.1) on ubuntu

2012-02-04T00:21:00.002+05:30

While running bundle install, got following error:
Installing rb-appscript (0.6.1) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

/home/ritesh/.rvm/rubies/ruby-1.9.3-p0/bin/ruby extconf.rb
extconf.rb:44: Use RbConfig instead of obsolete and deprecated Config.
create /home/ritesh/.rvm/gems/ruby-1.9.3-p0@koodrails/gems/rb-appscript-0.6.1/src/osx_ruby.h ...
create /home/ritesh/.rvm/gems/ruby-1.9.3-p0@koodrails/gems/rb-appscript-0.6.1/src/osx_intern.h ...
creating Makefile

make
Makefile:226: warning: overriding commands for target `/home/ritesh/.rvm/gems/ruby-1.9.3-p0@koodrails/gems/rb-appscript-0.6.1/lib'
Makefile:224: warning: ignoring old commands for target `/home/ritesh/.rvm/gems/ruby-1.9.3-p0@koodrails/gems/rb-appscript-0.6.1/lib'
compiling src/rbae.c
src/rbae.c:13:27: fatal error: Carbon/Carbon.h: No such file or directory
compilation terminated.
make: *** [rbae.o] Error 1

Gem files will remain installed in /home/ritesh/.rvm/gems/ruby-1.9.3-p0@koodrails/gems/rb-appscript-0.6.1 for inspection.
Results logged to /home/ritesh/.rvm/gems/ruby-1.9.3-p0@koodrails/gems/rb-appscript-0.6.1/./gem_make.out
An error occured while installing rb-appscript (0.6.1), and Bundler cannot continue.
Make sure that `gem install rb-appscript -v '0.6.1'` succeeds before bundling.

Yet looking for solution to fix the issue, if someone can help.

Getting error "can't activate sqlite3 (~> 1.3.5), already activated sqlite3-1.3.4" when upgrading to Rails 3.2

2012-01-31T20:39:00.004+05:30

Upgradation from Rails 3.1 to Rails 3.2 done successfully. When starting server, getting error :

Exiting
/home/ritesh/.rvm/gems/ruby-1.9.3-p0@global/gems/bundler-1.0.21/lib/bundler/rubygems_integration.rb:153:in `block in replace_gem': Please install the sqlite3 adapter: `gem install activerecord-sqlite3-adapter` (can't activate sqlite3 (~> 1.3.5), already activated sqlite3-1.3.4. Make sure all dependencies are added to Gemfile.) (LoadError)
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:3:in `<top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:251:in `require'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:251:in `block in require'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:234:in `block in load_dependency'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:639:in `new_constants_in'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:234:in `load_dependency'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:251:in `require'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/connection_adapters/abstract/connection_specification.rb:48:in `resolve_hash_connection'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/connection_adapters/abstract/connection_specification.rb:39:in `resolve_string_connection'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/connection_adapters/abstract/connection_specification.rb:23:in `spec'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/connection_adapters/abstract/connection_specification.rb:127:in `establish_connection'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/railtie.rb:76:in `block (2 levels) in <class:Railtie>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/lazy_load_hooks.rb:43:in `block in run_load_hooks'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/lazy_load_hooks.rb:42:in `each'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.2.0/lib/active_record/base.rb:709:in `<top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/omniauth-identity-1.0.0/lib/omniauth/identity/models/active_record.rb:6:in `<module:Models>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/omniauth-identity-1.0.0/lib/omniauth/identity/models/active_record.rb:5:in `<module:Identity>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/omniauth-identity-1.0.0/lib/omniauth/identity/models/active_record.rb:4:in `<module:OmniAuth>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/omniauth-identity-1.0.0/lib/omniauth/identity/models/active_record.rb:3:in `<top (required)>'
from /home/ritesh/projects/projects/crowd/app/models/crowd/credential.rb:1:in `<top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:469:in `load'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:469:in `block in load_file'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:639:in `new_constants_in'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:468:in `load_file'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:353:in `require_or_load'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:502:in `load_missing_constant'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:192:in `block in const_missing'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:190:in `each'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:190:in `const_missing'
from /home/ritesh/projects/projects/crowd/config/initializers/omniauth.rb:4:in `block in <top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/omniauth-1.0.0/lib/omniauth/builder.rb:7:in `initialize'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/actionpack-3.2.0/lib/action_dispatch/middleware/stack.rb:43:in `new'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/actionpack-3.2.0/lib/action_dispatch/middleware/stack.rb:43:in `build'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/actionpack-3.2.0/lib/action_dispatch/middleware/stack.rb:112:in `block in build'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/actionpack-3.2.0/lib/action_dispatch/middleware/stack.rb:112:in `each'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/actionpack-3.2.0/lib/action_dispatch/middleware/stack.rb:112:in `inject'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/actionpack-3.2.0/lib/action_dispatch/middleware/stack.rb:112:in `build'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/engine.rb:470:in `app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/application/finisher.rb:32:in `block in <module:Finisher>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:30:in `instance_exec'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:30:in `run'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:54:in `each'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:54:in `run_initializers'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/application.rb:136:in `initialize!'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/ritesh/projects/projects/crowd/spec/dummy/config/environment.rb:5:in `<top (required)>'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:4:in `require'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:4:in `block in <main>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:1:in `new'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:1:in `<main>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands/server.rb:46:in `app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands/server.rb:70:in `start'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands.rb:55:in `block in <top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands.rb:50:in `tap'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands.rb:50:in `<top (required)>'
from /home/ritesh/projects/projects/crowd/spec/dummy/script/rails:6:in `require'
from /home/ritesh/projects/projects/crowd/spec/dummy/script/rails:6:in `<top (required)>'
from script/rails:6:in `load'
from script/rails:6:in `<main>'

To fix the error:

Change the sqlite version in .gemspec from

s.add_development_dependency "sqlite3"

s.add_development_dependency "sqlite3" , "~> 1.3.5"

and run 'bundle install'

Getting error 'undefined method `before_dispatch' for class `Rails::Rack::Logger' (NameError) '

2012-01-31T20:18:00.000+05:30

Upgradation from Rails 3.1 to Rails 3.2 done successfully. When starting rails server getting following error:

/home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/core_ext/module/aliasing.rb:31:in `alias_method': undefined method `before_dispatch' for class `Rails::Rack::Logger' (NameError)
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/core_ext/module/aliasing.rb:31:in `alias_method_chain'
from /home/ritesh/projects/projects/crowd/spec/dummy/config/initializers/quite_assets.rb:6:in `block in <top (required)>'
from /home/ritesh/projects/projects/crowd/spec/dummy/config/initializers/quite_assets.rb:2:in `class_eval'
from /home/ritesh/projects/projects/crowd/spec/dummy/config/initializers/quite_assets.rb:2:in `<top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:245:in `load'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:245:in `block in load'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:236:in `load_dependency'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.0/lib/active_support/dependencies.rb:245:in `load'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/engine.rb:588:in `block (2 levels) in <class:Engine>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/engine.rb:587:in `each'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/engine.rb:587:in `block in <class:Engine>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:30:in `instance_exec'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:30:in `run'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:54:in `each'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/initializable.rb:54:in `run_initializers'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/application.rb:136:in `initialize!'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/ritesh/projects/projects/crowd/spec/dummy/config/environment.rb:5:in `<top (required)>'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:4:in `require'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:4:in `block in <main>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:1:in `new'
from /home/ritesh/projects/projects/crowd/spec/dummy/config.ru:1:in `<main>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands/server.rb:46:in `app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands/server.rb:70:in `start'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands.rb:55:in `block in <top (required)>'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands.rb:50:in `tap'
from /home/ritesh/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.0/lib/rails/commands.rb:50:in `<top (required)>'
from /home/ritesh/projects/projects/crowd/spec/dummy/script/rails:6:in `require'
from /home/ritesh/projects/projects/crowd/spec/dummy/script/rails:6:in `<top (required)>'
from script/rails:6:in `load'
from script/rails:6:in `<main>'

To fix the error,

Place the following code in config/initializers/quiet_assets.rb

Rails.application.assets.logger = Logger.new('/dev/null')
Rails::Rack::Logger.class_eval do
  def call_with_quiet_assets(env)
    previous_level = Rails.logger.level
    Rails.logger.level = Logger::ERROR if env['PATH_INFO'].index("/assets/") == 0
    call_without_quiet_assets(env).tap do
      Rails.logger.level = previous_level
    end
  end
  alias_method_chain :call, :quiet_assets

end

Update Rails 3.1 to Rails 3.2

2012-01-31T19:33:00.002+05:30

In Gemfile, change following versions of assets and rails

gem 'rails', '3.2.0'

group :assets do
  gem 'sass-rails', "  ~> 3.2.3"
  gem 'coffee-rails', "~> 3.2.1"
  gem 'uglifier', '>= 1.0.3'
end

Run 'bundle update'

Getting error "File Error: data may have been lost" while using spreadsheet and exporting excel

2012-01-01T23:42:00.002+05:30

I am using "Spreadsheet" gem with Rails 2.3.8. Microsoft Office 2007 is installed on my system.
I successfully fitted the code snippets in one of my controller.
I just wrote the code to create Worksheet and pushed one row record in it.
Number of records pushed in that row is around 330.
When I export the spreadsheet/excel, I got following error:

"File Error: data may have been lost"

Clicked on Ok and it created the excel file with the File Type "Microsoft Office Excel 97-2003 Worksheet" with one sheet having 1 row.
When closely analyzed the sheet, I found that Number of maximum columns that can be in that sheet is only 256 and as I was trying to have around 330 columns hence I was getting the error.

What's new in Edge Rails: EXPLAIN

2011-12-24T09:56:00.000+05:30

What's new in Edge Rails: EXPLAIN:
There are some new features related to EXPLAIN in the forthcoming Ruby on Rails 3.2 we'd like
to share:

Running EXPLAIN manually
Automatic EXPLAIN for slow queries
Silencing automatic EXPLAIN

As of this writing they are available for the adapters sqlite3, mysql2, and postgresql.

Running EXPLAIN Manually

You can now run EXPLAIN on the SQL generated by a relation this way:

User.where(:id => 1).joins(:posts).explain

The result of that method call is a string that carefully imitates the output of database shells.

Please note that explain runs the query or queries and asks the database for their respective query plan afterwards. This is because due to eager loading a relation may trigger several queries to fetch the records and their associations, and in such cases some queries need the result of the previous ones.

If the relation triggers several queries the method still returns a single string with all the query plans. This is an output meant for human consumption so we preferred to present everything as a string in a format which is familiar right away rather than a structure.

Automatic EXPLAIN For Slow Queries

Rails 3.2 has the ability to help in detecting slow queries.

New applications get

config.active_record.auto_explain_threshold_in_seconds = 0.5

in config/environments/development.rb. Active Record monitors queries and if they take more than that threshold their query plan will be logged using warn.

That works for anything running find_by_sql (which is almost everything, since most of Active Record ends up calling that method). In the particular case of relations, the threshold is compared against the total time needed to fetch the records, not against the time taken by each individual query. Because conceptually we are concerned with the cost of the call

User.where(:id => 1).joins(:posts).explain

rather than the cost of the different queries that call may trigger due to the implementation.

By default the threshold is nil in the test and production environments, which means the feature is disabled.

The value of that parameter is nil also if the threshold is not set, so existing applications will need to add it by hand if they migrate to 3.2 to be able to enable automatic EXPLAIN.

Silencing Automatic EXPLAIN

With automatic EXPLAIN enabled, it could still be the case that some queries are just slow and you know they have to be. For example, a heavyweight report in the backoffice.

The macro silence_auto_explain allows you to avoid having EXPLAIN run repeatedly in those areas of code:

ActiveRecord::Base.silence_auto_explain do
 # no automatic EXPLAIN here
end

Interpreting Query Plans

The interpretation of the query plans is another topic, these are some pointers:

Happy debugging!

Installing ZeroMQ for Rubyists on Ubuntu

2011-12-13T23:52:00.000+05:30

To install zmq gem in Ruby on Rails on Ubuntu, execute the command:

sudo apt-get install zeromq-bin libzmq-dbg libzmq-dev libzmq0

then

sudo gem install zmq

Getting error "Illegal octal digit"

2011-12-03T23:38:00.001+05:30

While trying to execute below case method to display month, getting 'Illegal octal digit' for August and September month only:

def self.convert_month(month)
    case month
      when "Jan" :         01
      when "Feb" :        02
      when "Mar" :      03
      when "Apr" :        04
      when "May" :       05
      when "Jun" :         06
      when "Jul" :          07
      when "Aug" :       08
      when "Sep" :        09
      when "Oct" :        10
      when "Nov" :       11
      when "Dec" :

end

Solution

Ruby is interpreting numbers that have a leading 0 as being in octal (base 8). Thus the digits 8 and 9 are not valid. So, I removed leading zero from Aug and Sep month and changed the method as:

when "Aug" : 8
when "Sep" : 9