Software Development

Error: Cannot find module 'npmlog'

2013-05-20T15:27:00.001-07:00

1. npm install -g yo grunt-cli bower gives the error:

Fix : sudo curl https://npmjs.org/install.sh | sh

How to upgrade Node.js

2013-05-20T15:15:00.001-07:00

1. Check the version : $node --version
output will be like : n@0.9.3 /usr/lib/node_modules/n

2. To upgrade, run : $n 0.9.3
where, 0.9.3 is from the output of step 1.

Open a new terminal and type: $node --version
You should see the upgraded version.

SQLite3::BusyException: database is locked: ROLLBACK TO SAVEPOINT active_record_1

2013-05-17T10:48:00.002-07:00

Caused SQLite3 to lock due to bug in a test. To fix:

1. ps -a | grep ruby
2. kill -s 9 12345

12345 is the process id that is the zombie rspec process.

WARNING: Nokogiri was built against LibXML version 2.8.0, but has dynamically loaded 2.9.0

2013-05-14T14:12:00.003-07:00

Copied from https://github.com/sparklemotion/nokogiri/issues/742

Moved gem 'nokogiri' in the Gemfile to the top (just below gem 'rails') then:

brew uninstall libxml2
gem uninstall nokogiri
gem install nokogiri

AbstractController::ActionNotFound:

2013-05-13T18:07:00.002-07:00

Could not find devise mapping for path "/users/sign_in?user%5Bemail%5D=bparanj%40gmail.com&user%5Bpassword%5D=secret".
This may happen for two reasons:

1) You forgot to wrap your route inside the scope block. For example:

devise_scope :user do
get "/some/route" => "some_devise_controller"
end

2) You are testing a Devise controller bypassing the router.
If so, you can explicitly tell Devise which mapping to use:

@request.env["devise.mapping"] = Devise.mappings[:user]

Solution:

before :each do
request.env['devise.mapping'] = Devise.mappings[:user]
end

How to select the non highlighted button in the popup window on Mac OS

2013-05-02T18:19:00.002-07:00

Go to Preferences -> Keyboard. At the bottom, turn on "All controls" under "Full Keyboard Access". Hit space to activate the secondary button.

GitHub Error – You don’t exist, go away!

2013-05-01T22:29:00.001-07:00

At the terminal run:

dscacheutil -flushcache

How to checkout a specific tag from a Git repo

2013-05-01T13:47:00.001-07:00

git checkout tag-name

How to Setup Development Environment to Contribute to Rails

2013-04-26T10:48:00.003-07:00

Use the Rails Dev Box available at : https://github.com/rails/rails-dev-box

How to store array in mysql database in a Rails project

2013-04-25T11:40:00.003-07:00

1. The column type should be text
2. serialize the column. In the active record class : serialize :your_field
3. Book.new(:your_field => [1,2])

How to limit svn log output to a given number of entries

2013-04-23T11:36:00.001-07:00

Use limit option: svn log -l 5

Correction to Example in Ruby Programming Language

2013-04-22T12:24:00.001-07:00

In Ruby 2.0, I had to make changes to the given code in the book:

birthyear = 1975

generation = case birthyear
when 1946..1963 then "Baby Boomer"
when 1964..1976
"Generation X"
when 1978..2000
"Generation Y"
else nil
end

p generation

How to use VCR, Webmock with RSpec

2013-04-18T16:30:00.001-07:00

1. Add the gems to the Gemfile under test group:
gem "webmock"
gem "vcr"

2. bundle

3. require 'vcr' as the first line in spec_helper.rb

4. Add

VCR.configure do |c|
c.cassette_library_dir = 'spec/fixtures/cassettes'
c.hook_into :webmock
c.ignore_localhost = false
c.allow_http_connections_when_no_cassette = true
end

inside the configure block.

5. Add WebMock.allow_net_connect! in the before block in the specs.
6. Wrap your network calls using :
VCR.use_cassette do
controller code that accesses network goes here
end

Two different ways to execute a block

2013-04-12T15:54:00.002-07:00

It is familiar that you will see yield being used when the block is anonymous and block.call being used when the block is explicit in the list of parameters for the method. Actually, you can use yield even when the block is explicitly passed to the method:

def foo(&block)
yield
block.call
end

foo { puts 'hi hey again' }

Setting two spaces as the default in Sublime Text 2

2013-04-02T11:49:00.002-07:00

{
    "tab_size": 2,
    "translate_tabs_to_spaces": true
}

Save this in the Preferences -> Settings - Default file.

Installing Guest Additions on Ubuntu 12.04

2013-04-02T10:43:00.001-07:00

1. sudo apt-get install virtualbox-guest-additions-iso
2. Boot the guest OS inside Virtualbox
3. In the virtual box menu, use Devices -> Install Guest Additions.

Reference: ubuntuforums.org

uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)

2013-04-01T16:14:00.001-07:00

This happens when creating a new project in Rails 2.3.8 if the Ruby gems version is 1.8.24.
Solution:

gem update --system 1.5.3

Now, rails blog will create a new project.

program rails is not installed ubuntu rvm rails 2.3.8

2013-04-01T16:03:00.001-07:00

1. Type : gem env, look at the EXECUTABLE DIRECTORY value

2. Add the path to that directory to ~/.bashrc:
PATH="${PATH}:/home/your-user-name/.rvm/gems/ruby-1.8.7-p299/bin"

3. Open a new terminal

4. Type : rails -v

You will now see that rails command is recognized.

How to configure Sublime Text 2 to use Ruby 2.0 using RVM

2013-03-29T18:32:00.004-07:00

{ "env":{ "PATH":"${HOME}/.rvm/bin:${PATH}" }, "cmd": ["rvm-auto-ruby", "$file"], "file_regex": "^(...*?):([0-9]*):?([0-9]*)", "selector": "source.ruby" }

Copy this file to your rvm.sublime.build file.

For more info: Sublime Text 2 Integration With RVM and Rspec: Take Number 2

How to configure rspec to test controller macros

2013-03-25T17:40:00.000-07:00

Include the line:
config.include OnboardingControllerMacros, :type => :controller

in spec_helper.rb

Readline was unable to be required, if you need completion or history install readline then reinstall the ruby.

2013-03-18T19:34:00.003-07:00

This happens on Ubuntu 12 when installing Ruby 2.0 using RVM. To fix this follow the instructions below:

If you're using Ubuntu 12.04, DO NOT pkg install readline, with or without --skip-autoreconf. After you've done that, either readline or zlib will be broken no matter what combination of switches you give to rvm install ruby-2.0.0-p0 .
To get it to work, do the apt-get install that rvm requirements tells you to do, do a rvm pkg uninstall readline and then do a simple rvm remove ruby-2.0.0-p0; rvm install ruby-2.0.0-p0

Now the irb should work fine without any warnings.

http://stackoverflow.com/questions/8176076/how-to-get-readline-support-in-irb-using-rvm-on-ubuntu-11-10

iPhone 5 cord stuck in USB Port

2013-03-12T14:31:00.001-07:00

You can easily remove your iPhone 5 cable stuck in USB port by using either your shirt collar stays or a toothpick. Just stick it inside the USB port, sitting on top of the cable and pull them together.

Accessing Git Repository on Github

2013-02-25T16:20:00.000-08:00

Problem:
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Solution:

Password Caching (Explains how to use https to access repository and cache password so you don't get annoying password prompt whenever you have to access the github repo)

1. curl -s -O \

  http://github-media-downloads.s3.amazonaws.com/osx/git-credential-osxkeychain

chmod u+x git-credential-osxkeychainsudo mv git-credential-osxkeychain `dirname \`which git\``
git config --global credential.helper osxkeychain

Using Bundler Outside Rails

2013-02-25T14:43:00.003-08:00

1. bundle init
2. Open Gemfile and add your gems : gem 'highline'
3. bundle

Bundler without Rails

Using Phusion Passenger as a Rails Server on Mac OS X 10.7.5

2013-02-22T18:24:00.000-08:00

Software used : RVM Passenger 3.0 on Mac OS X 10.7.5

1. rvm use 1.9.3
2. gem install passenger
3. rvm get head
4. rvm reload
5. rvm repair all
6. passenger-install-apache2-module