Reddy On Rails more than Ruby

Security issues with git : upted required for Git clients

2014-12-18T14:13:00.000-08:00

Even though the issue may not affect Linux users, if you are a
hosting service whose users may fetch from your service to Windows
or Mac OS X machines, you are strongly encouraged to update to
protect such users who use existing versions of Git.

source :

 http://article.gmane.org/gmane.linux.kernel/1853266

 Updated versions on Github are here :

 GitHub for Windows and GitHub for Mac

making underscore.js dependency to angular js

2014-11-06T10:18:00.002-08:00

var app = angular.module('app', ['underscore']);
app.controller('AppController', ['$scope', '_', function ($scope, _) {
initialize = function () {
_.keys($scope);
}
initialize();
}]);

underscore.factory('_', function () {
return window._;
});

Ruby 2.1.0 some useful changes

2014-05-08T13:52:00.002-07:00

return in lambda
def yield_me
yield
end

def run
yield_me(&lambda {return "call from lambda"})
"call from run method"
end

run   #=> "call from run method"
The example above would have returned "call from lambda" in Ruby previous ruby versions
---------------------------------------------------------------------------------------------------------------
#singleton_class?
class Test
singleton_class?     #=> false
class << self
    singleton_class?   #=> true
end
end

Object#singleton_method
class Test
def self.one
end

def two
end
end

# returns class method
Test.singleton_method(:one)    #=> #
# doesn't return instance method
Test.singleton_method(:two)   #=> #-----------------------------------------------------------------------------------------------------------------
Method#original_name
To return the un-aliased name.
class Example
def foo
    "foo"
end
alias bar foo
end

example = Example.new
example.method(:foo).original_name            #=> :foo
example.method(:bar).original_name            #=> :foo
Example.instance_method(:bar).original_name   #=> :foo

For more changes please visit here:

https://github.com/ruby/ruby/blob/v2_1_0/NEWS

Ruby 2.1 and Garbage Collection issue and memory bloats in production unicorn and Phusion passenger

2014-03-28T10:57:00.000-07:00

Are you working with Unicorn and getting memory leak issues with ruby 2.1 . A better explained scenario on memory allocation on heap with huge strings ,array and hashes in Ruby 2.1 by this author himself here :

http://www.atdot.net/~ko1/activities/rubyconf2013-ko1_pub.pdf

Whats the problem?

Tim Robertson explained this scenario in his blog :
http://www.omniref.com/blog/blog/2014/03/27/ruby-garbage-collection-still-not-ready-for-production/

Well not sure about unicorn solution but Aman Gupta has a solution for Phusion Passenger.
as announced an Out-Of-Band garbage collector for Ruby 2.1.

Here is the Phusion Passenger blog on that one and usage.

Phusion Passenger now supports the new Ruby 2.1 Out-Of-Band GC.

Ruby 1.9.3 (Rails 3) Ruby 2.0 (Rails 4) Performance test and improvements

2013-08-08T18:18:00.002-07:00

Using Mac OS and Webrick in local environment
time -p bundle exec rake environment
real 6.69
user 4.76
sys 0.79

export RUBY_GC_MALLOC_LIMIT=1000000000
export RUBY_FREE_MIN=500000
export RUBY_HEAP_MIN_SLOTS=40000

AFTER we set the above exports , check the below performance
time -p bundle exec rake environment
real 5.36
user 3.19
sys 1.05

Also tested in request to response scenario using apache bench with 100 requests
Ruby 1.9.3 (Rails 3)
------------------------------------------------------------------------------------------
ab -n 100 -c 1 http://localhost:3000/
------------------------------------------------------------------------------------------
BEFORE FLAGS SET (ruby-1.9.3-p194 [ x86_64 ])
------------------------------
Server Software:        WEBrick/1.3.1
Server Hostname:        127.0.0.1
Server Port:            3000

Document Path:          /
Document Length:        96050 bytes

Concurrency Level:      1
Time taken for tests:   391.883 seconds
Complete requests:      100
Failed requests:        13
   (Connect: 0, Receive: 0, Length: 13, Exceptions: 0)
Write errors:           0
Total transferred:      9698686 bytes
HTML transferred:       9604985 bytes
Requests per second:    0.26 [#/sec] (mean)
Time per request:       3918.831 [ms] (mean)
Time per request:       3918.831 [ms] (mean, across all concurrent requests)
Transfer rate:          24.17 [Kbytes/sec] received

Connection Times (ms)
              min mean[+/-sd] median   max
Connect:     2963 3585 583.6   3430    5625
Processing:     0 334 2625.5      1   26154
Waiting:        0 333 2625.5      0   26153
Total:       2963 3919 2905.2   3430   31529

Percentage of the requests served within a certain time (ms)
50%   3430
66%   3532
75%   3623
80%   3710
90%   4407
95%   6346
98%   7244
99% 31529
100% 31529 (longest request)
---------------------------------------------------------------
AFTER FLAGS SET (ruby-1.9.3-p194 [ x86_64 ])
---------------------------------------------------------------
export RUBY_GC_MALLOC_LIMIT=1000000000
export RUBY_FREE_MIN=500000
export RUBY_HEAP_MIN_SLOTS=40000

Server Software:        WEBrick/1.3.1
Server Hostname:        127.0.0.1
Server Port:            3000

Document Path:          /
Document Length:        96050 bytes

Concurrency Level:      1
Time taken for tests:   368.903 seconds
Complete requests:      100
Failed requests:        14
   (Connect: 0, Receive: 0, Length: 14, Exceptions: 0)
Write errors:           0
Total transferred:      9714323 bytes
HTML transferred:       9620622 bytes
Requests per second:    0.27 [#/sec] (mean)
Time per request:       3689.025 [ms] (mean)
Time per request:       3689.025 [ms] (mean, across all concurrent requests)
Transfer rate:          25.72 [Kbytes/sec] received

Connection Times (ms)
              min mean[+/-sd] median   max
Connect:     2563 3388 634.5   3395    5351
Processing:     0 301 2692.0      0   26860
Waiting:        0 301 2692.0      0   26859
Total:       2563 3689 2973.1   3397   32211

Percentage of the requests served within a certain time (ms)
50%   3397
66%   3656
75%   3753
80%   3809
90%   3928
95%   5208
98%   6949
99% 32211
100% 32211 (longest request)
----------------------------------------------------

Ruby 2.0 (Rails 4)
-------------------------------------------------------------------------------------------------------
ab -n 100 -c 1 http://127.0.0.1:3000/
------------------------------------------------------------------------------------------------------
Server Software:        WEBrick/1.3.1
Server Hostname:        127.0.0.1
Server Port:            3000

Document Path:          /?locale=uk
Document Length:        20815 bytes

Concurrency Level:      1
Time taken for tests:   181.485 seconds
Complete requests:      100
Failed requests:        5
   (Connect: 0, Receive: 0, Length: 5, Exceptions: 0)
Write errors:           0
Total transferred:      2185395 bytes
HTML transferred:       2081495 bytes
Requests per second:    0.55 [#/sec] (mean)
Time per request:       1814.851 [ms] (mean)
Time per request:       1814.851 [ms] (mean, across all concurrent requests)
Transfer rate:          11.76 [Kbytes/sec] received

Connection Times (ms)
              min mean[+/-sd] median   max
Connect:       37 1590 658.0   1678    5320
Processing:     0 225 918.2      0    8042
Waiting:        0 225 917.9      0    8041
Total:       1585 1815 818.9   1679    8079

Percentage of the requests served within a certain time (ms)
50%   1679
66%   1685
75%   1690
80%   1694
90%   1749
95%   1995
98%   6240
99%   8079
100%   8079 (longest request)
-------------------------------------------------------------------------------------------------
AFTER FLAG SET (Ruby 2.0 (Rails 4)
export RUBY_GC_MALLOC_LIMIT=1000000000
export RUBY_FREE_MIN=500000
export RUBY_HEAP_MIN_SLOTS=40000
----------
Server Software:        WEBrick/1.3.1
Server Hostname:        127.0.0.1
Server Port:            3000

Document Path:          /?locale=uk
Document Length:        20815 bytes

Concurrency Level:      1
Time taken for tests:   172.496 seconds
Complete requests:      100
Failed requests:        12
   (Connect: 0, Receive: 0, Length: 12, Exceptions: 0)
Write errors:           0
Total transferred:      2185386 bytes
HTML transferred:       2081486 bytes
Requests per second:    0.58 [#/sec] (mean)
Time per request:       1724.962 [ms] (mean)
Time per request:       1724.962 [ms] (mean, across all concurrent requests)
Transfer rate:          12.37 [Kbytes/sec] received

Connection Times (ms)
              min mean[+/-sd] median   max
Connect:       36 350 695.0     40    3408
Processing:     0 1374 737.0   1564    3935
Waiting:        0 1374 736.6   1563    3934
Total:       1582 1725 406.2   1607    3973

Percentage of the requests served within a certain time (ms)
50%   1607
66%   1617
75%   1640
80%   1651
90%   1909
95%   3031
98%   3408
99%   3973
100%   3973 (longest request)

Upgrading tips for Ruby 2.0 & Rails 4 from Ruby 1.9.3 & Rails 3

2013-08-06T14:57:00.000-07:00

Ruby 2.0
1. mostly compatible with Ruby 1.9.3 version
3. more refinements and code related features;
4. Asynchronous exception handling API
5. More built in libraries
6. Debugging support(DTrace,TracePoint)
7. Performace enhancements like GC optimization and better method dispatch
8. Customize VM ENV variables

Rails 4.0
0.Test coverage is should be good before starting an upgrade.
1. By default thread safe: so have to use gems which are thread safe
2. better utf-8 support
3. better with unicorn like servers
4. Rails 4 prefers Ruby 2.0 and requires 1.9.3 or newer.
5. Some ActionController classes moved to ActionDispatch
6.secret_key_base upgraded carefully , cookies signed based on the new secret_key_base in Rails 4.x are not backwards compatible with Rails( Wait for all users to accommodate new token )
7. Better caching (https://gist.github.com/szimek/1669330)
8.Official upgrade link
http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html
9. buy a book to upgrade rails 4 ? here is the link : https://leanpub.com/upgradetorails4

Ruby 'and' 'or' vs && , || precedence

2013-07-19T15:11:00.000-07:00

Just like in maths : Order of Operations - BODMAS or

In general programming languages, && has higher precedence than || operator.

But in Ruby it is not like that as and or have same order of precedence.

Lets see one example :

"a" || "b" && "c" will be assumed as => "a" || ("b" && "c")

output: "a" ("b", "c" are never called) why as "a" is always true.

here && has higher precedence than ||

Lets see with and or operations

"a" or "b" and "c" will be assumed as => ("a" or "b") and "c"

output: "c"

helpful GIT command aliases

2013-07-18T11:54:00.001-07:00

[alias]
   st = status -sb
   ci = commit
   br = branch
   df = diff
   lg = log --pretty=format:'%Cred%h%Creset -%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset'
   lg = log -p
   co = checkout
   cp = cherry-pick
   tree = log --graph --decorate --pretty=oneline --abbrev-commit --all
   pom = push origin master
   amend = commit --amend -C HEAD
   wdiff = diff --color-words
   standup = log --since yesterday --author jreddy@reddyonrails.com
   rst = reset --hard
   pr = pull --rebase

You can also add aliases like so, and they will get added to your .gitconfig file automatically.

$ git config –-global --edit

Error running 'requirements_brew_libs_install libksba' or libgpg-error Ruby 2.0.0 on MAC, brew and RVM

2013-04-09T15:45:00.000-07:00

Problem:
If you have problem installing ruby 2.0.0 on your mac using rvm and brew. And the problem could be timeout error .

rvm install ruby-2.0.0-p0

Installing requirements for osx, might require sudo password.
Already up-to-date.
Installing required packages: libksba....
^CError running 'requirements_brew_libs_install libksba',
please read /Users/XXX/.rvm/log/ruby-2.0.0-p0/package_install_libksba.log

log file :

(curl: (56) Recv failure: Operation timed out)

Solution:

vi /usr/local/Library/Formula/libgpg-error.rb
Replace: url 'ftp://ftp.gnupg.org/gcrypt/libgpg-error/libgpg-error-1.9.tar.gz'
with url 'http://www.mirrorservice.org/sites/ftp.gnupg.org/gcrypt/libgpg-error/libgpg-error-1.11.tar.gz'

same case with libksba

This should works if it complain sha1 stuff replace expected one on ruby code.

Brew Update issue

2013-03-28T12:30:00.000-07:00

$ brew update
error: The following untracked working tree files would be overwritten by merge:
    Library/Formula/libmusicbrainz.rb
Please move or remove them before you can merge.
Aborting
Error: Failure while executing: git pull -q origin refs/heads/master:refs/remotes/origin/master

Solution:

rm /usr/local/Library/Formula/libmusicbrainz.rb
brew update

Rails pg gem '0.14.1' on Mac fails and solution

2013-01-24T22:15:00.004-08:00

pg.c: In function ‘Init_pg_ext’:
pg.c:384: error: ‘PQPING_OK’ undeclared (first use in this function)
pg.c:384: error: (Each undeclared identifier is reported only once
pg.c:384: error: for each function it appears in.)
pg.c:386: error: ‘PQPING_REJECT’ undeclared (first use in this function)
pg.c:388: error: ‘PQPING_NO_RESPONSE’ undeclared (first use in this function)
pg.c:390: error: ‘PQPING_NO_ATTEMPT’ undeclared (first use in this function)
make: *** [pg.o] Error 1

Solution:
env ARCHFLAGS="-arch x86_64" gem install pg -- --with-pg-config=/Library/PostgreSQL/9.2/bin/pg_config

EDIT :
If you dont know where your pg_config is. Assume you are on Linux/Mac system, using the command 'find' should help

find / -name pg_config

How to copy postgresql data from heroku production

2013-01-24T21:53:00.000-08:00

Steps to get the copy of heroku deployed application database to localhost .

1 step: Create a backup on heroku production

           heroku pgbackups:capture --expire

2 step: Get the latest back up to local by curl method

           curl -o backup.dump `heroku pgbackups:url`
3 step: Restore to localhost database using the followng comand

   pg_restore --verbose --clean --no-acl --no-owner -h localhost -d your_database_name backup.dump

In Ruby, private methods are visible in derived classes

2012-11-16T13:35:00.001-08:00


    class Base
    private
      def hello

      end
    end

then methods in the derived class can call it:


    class Derived < Base
      def say
        hello # this is allowed in Ruby
      end
    end

Simply to say this :

in C++ and OOP languages, “private” means “private to this class”,

while in Ruby it means “private to that instance”. Again here class is itself an object :-)

Thats means private method will have only one receiver that is self.

Features of Ruby on Rails 4.0

2012-10-18T11:17:00.003-07:00

Features of Rails 4.0:
    •    strong_parameters
    •    Rails.queue
    •    Turbolinks
    •    Russian Doll Caching (cache_digests)
    •    ActionController::Live (streaming)
    •    PATCH verb
    •    Routing concerns
    •    Extraction of activeresource
    •    ActiveRecord::Relation changes and improvements
    •    Removal of plugin support (not gems; only those that are installed in vendor/plugins)
    •    Removal of Rails 2 finder syntax
    •    Deprecation of most dynamic finders
    •    Deprecation of eager-evaluated scopes

Slide deck: speakerdeck.com/u/alindeman/p/rails-4-dot-0-whirlwind-tour

Video: http://vimeo.com/51181496

tooltipclass.js for drop down options when mouse over

2012-07-15T17:00:00.005-07:00

code : https://github.com/reddyonrails/tooltipclass.js

Description:
 This code is to tooltip drop down option when mouse over. TooltipClass uses json data source .
If this datasource is empty will fetch from ajax url passed from source list url.

You can set a template for each tooltip for drop down box.

sample source params to select particular select box.

Usage:
var dataSourceList = {
    'portfolio': {
        'targetElement': '#analysisjob_portfolio_id',
        'url': '/portfolios',
        'sourceName': 'portfolio',
        'primaryKey': 'portfolio.PortfolioId',
        'jasonData': {},
        'template': "" +
            "<%= item.Name%>" + "
" +
            "<%= item.Description%>" + "
" +
            ""
     }
}
targetElement : select box id
url: ajax url to fetch data
sourceName: json root
primaryKey: key with which we search for json data for each option
template: you can define tooltip structure

loadSource and call tooltipify function like this :
       var source = dataSourceList.portfolio
       var test = TooltipClass.initialize(source);
        test.toolTipfy();

Requirements:
http://twitter.github.com/bootstrap/javascript.html (tooltip,popover)
jquery
underscore.js

Tested in firefox

Kaminari plugin with column_sorting and jquery_ajax

2011-05-25T10:16:00.000-07:00

https://github.com/reddyonrails/Kaminari_column_sorting_jquery_ajax

The above example code for column sorting through ajax calls when doing pagination.

Better to use sorting image arrows for column heading for visual appealing

Please visit for original kaminari pagination plugin here.
https://github.com/amatsuda/kaminari

For those using MacPorts, ImageMagick 6.6.5 and Ruby 1.9.2.

2011-04-28T13:56:00.000-07:00

If anybody get this error :
/gems/carrierwave-0.5.3/lib/carrierwave/processing/rmagick.rb:248: [BUG] Segmentation fault
ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10.7.0]

Theses are the steps to avoid it (Port).
port uninstall ImageMagick
port edit ImageMagick
Add --disable-openmp to configure.args (near line 100)
port install ImageMagick

Uninstall imagemagick:

brew remove imagemagick

Delete the cache:

rm -rf 'brew --cache imagemagick'

Then re-install the package with this flag:

brew install -f imagemagick --disable-openmp

how to stop Rspec run on first failure :rspec tip

2011-02-14T15:27:00.000-08:00

Edit "spec/spec_helper.rb" with:
```
RSpec.configure {|config| config.fail_fast = true}
```
```
 
```
Set the fail_fast option to tell RSpec to stop the run on first failure.
```
 
```

Restful routes for non ID( primary key ) rails 3

2011-01-31T14:40:00.000-08:00

Lets suppose that you have a Profile model, and you have a resources :profiles route.

Generally, profile_path will build a path with the profile object’s ‘id’ in it:

profile = profile.find_by_name('jaganreddy')
  profile_path(profile)  # => "/profiles/1"

You can override to_param in your model to make profile_path build a path using the profile’s name instead of the profile’s id:

class Profile < ActiveRecord::Base

    def to_param # overridding default behaviour

       name

end

 end
    
  

  profile = Profile.find_by_name('jaganreddy')
  profile_path(profile)  # => "/profiles/jaganreddy"

Also take care for nested resources too

In your controller always looks for  
Profile.find_by_name(params[:id])

how to set primary key and autoincrement on non id column using rails 3 -- sqlite

2011-01-26T13:53:00.000-08:00

sqlite_adopter uses
       def default_primary_key_type
          if supports_autoincrement?
            'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'
          else
            'INTEGER PRIMARY KEY NOT NULL'
          end
        end
and under the create table definition the line says:
table_definition.primary_key(options[:primary_key] || Base.get_primary_key(table_name.to_s.singularize)) unless options[:id] == false

that means we should not set :id => false ... many people will do to avoid id column.. this is fine
but if you want other column as primary key add at table definition not at column definition.(dont add :id => false)..

adding primary_key at table definition will take care of removing id column. the following line will also add t ocolumn definition
'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'
ofcourse based on sqlite3 version...

      def supports_autoincrement? #:nodoc:
        sqlite_version >= '3.1.0'
      end
Note: so autoincrement for :primary_key is hard coded
sample:
create_table :students, :primary_key => student_id do |t|
   t.string :name
end
it generates students table as follows;
students;

student_id : primary key autoincrement

name : varchar

This is for what i am using version of rails : 3.0.3

undefined method `user_signed_in? with Rails 3.0.3 - Devise

2011-01-10T12:04:00.000-08:00

I just started a new rails 3.0.3 application after doing a gem update
(loaded rails 3.0.3 and devise 1.1.5) and I got the same error. This
was following the default devise install instructions.

answer:
for got to add
devise_for :users in routes.rb

Date sort in ruby from array can have date formats ,non date formats

2010-11-05T14:09:00.000-07:00

Date sorting(ruby) from array is easy if array contain strings with proper date formats. Sometime invalid date formats raise argument error.

Sample i have used for date column attribute as follows.
def sort_on_mature_date(listings)
    listings.sort do |x,y|
      x_matures_on = x.when_does_it_mature? #date type
      y_matures_on = y.when_does_it_mature? #date type
      begin Date.parse(x_matures_on)   rescue x_matures_on="1900-1-1" end    #string could be not a date like "now"
      begin Date.parse(y_matures_on) rescue y_matures_on="1900-1-1" end
      Date.parse(x_matures_on)<=>Date.parse(y_matures_on)
    end
end

Rails rounded corner box helper

2010-10-22T11:18:00.000-07:00

Here is the helper include in your rails app. You need to take care of images .
#usage:

<%top = {"background-image"=>"url('/images/accept_box_top.png')",:height=>"6px",:width=>"328px"}%>

<%mid = {"background-image"=>"url('/images/accept_box_mid.png')",:height=>"405px",:width=>"auto"}%>

<%bottom = {"background-image"=>"url('/images/accept_box_bottom.png')",:height=>"9px",:width=>"auto"}%>

<%content = {"padding"=>"15px 28px 22px 26px"}%>
<%=round_box(top,mid,bottom,content){|f| "nice box"} %>

Make sure that you pass right height and width. It automatically renders the box and content inside.
If you want you also add extra css attributes too!

#round_box_helper.rb

module RoundBoxHelper

def round_box(top, mid,bottom,content,&b)

     css_elements( top,mid,bottom,content)+

     "<div class = 'accept_gift_box'>

      <div class='accept_gift_box_top'></div>

        <div class='accept_gift_box_mid'>

          <div
class='accept_gift_box_content'>


"+b.call+"

          </div>

        </div>

    <div class='accept_gift_box_bottom'> </div>

</div>"

end

def css_elements top,mid,bottom,content

     "<style type='text/css'> " +

      ".accept_gift_box_top{"+

        parse_styles( top )+

      "}"+

       ".accept_gift_box_mid{"+

        parse_styles( mid )+

      "}"+

      ".accept_gift_box_bottom{"+

        parse_styles( bottom )+

      "}"+

      ".accept_gift_box_content{"+

        parse_styles( content )+

      "}"+

      ".accept_gift_box{"+

       "float:left;"+

      "}"+

     "</style>"

end

def parse_styles el

    str=""

    el.each_pair do |attr,value|

      str = str+attr.to_s+":"+value.to_s+";"

    end

    str

end

end

width and top of invisible element in IE may give 0 zero using jQuery

2010-09-28T09:45:00.000-07:00

jQuery element width for invisible element in IE will not give exact result.
But in Firefox it works perfectly.

$(e).width() //using jQuery to get the width.

i have used a way to solve this one by showing, calculate width and hiding the element.

$(e).
show(). // to get the width of visible element ==> IE issue
css({zoom: 1,left:$(e).position().left-parseInt($(e).width()),top:$(e).position().top}).
hide().

jQuery animation effect slide bug in IE 7

2010-09-28T09:34:00.000-07:00

The best example is for this ind of bug is presented by ryan as follows

http://www.ryancramer.com/misc/jquery_slide/#

the slide effects of jquery may not work 100% correctly in IE 6 & IE 7 . Effects are misbehave like effects complete till 50% or so...

So i have used show call back function to rescue the bug.. Though it is 100% not correct but once the effects renders second time it works perfectly.

So make it show and show it again..with less duration.. to avoid flickering effect.

$("my_element").show(1,function(){$(this).show("slide",{direction:"right"})})