Top 7 Myths about HTTPS | HttpWatch Blog

Myth #5 (Each HTTPS Site Needs its Own Public IP Address) is actually still true, but the rest of the article is worth reading.

Plotting graphs in Ruby with Gruff

Geoffrey Grosenbach has created Gruff for easily plotting graphs. It is written in pure Ruby and integrates with Rails applications.

It provides features as automatic sizing of dots and lines (the more values, the thinner the graph's elements), custom or predefined themes, different styles (bar, line, dot and many more) and multiple graphs in one chart.

Installation

In your Gemfile:

gem 'rmagick', :require => false
gem 'gruff'

Then run bundle install (and don't forget to restart your development server.)

Usage

This i...

Guide to localizing a Rails application

Localizing a non-trivial application can be a huge undertaking. This card will give you an overview over the many components that are affected.

When you are asked to give an estimate for the effort involved, go through the list below and check which points are covered by your requirements. Work with a developer who has done a full-app localization before and assign an hour estimate to each of these points.

Static text

  • Static strings and template text in app must be translated: Screens, mailer templates, PDF templates, helpe...

Sync confidential files between unixes using cloud storage and encfs

Note: You might also want to check out BoxCryptor which does pretty much the same, and is supported across many more platforms. I just didn't want to use Dropbox...

I use Ubuntu One to automatically sync confidential files between my machines. The encryption is done via encfs, which is a file-based encryption that simply puts encrypted versions of files from one folder into another. This is well-suited for cloud storage, since it allows syncing single files, not whole crypt containers.

Recipe

I'll ass...

Removing white space after links in HAML

TL;DR

%p
  #{link_to "label", "url"}!

Haml is a great engine for writing shorter, readable HTML. However, there is one thing that troubles me regularly. Consider this Haml code:

%p
  Visit our homepage at
  = link_to "www.makandra.com", "http://www.makandra.com"
  !

Haml will insert a space around the generated link, the result is this (see the space before the exclamation mark!):

<p>
  Visit our website at <a href="http://www.makandra.com">www.makandra.com</a> !
</p>

They suggest to us...

How to use pessimistic row locks with ActiveRecord

When requests arrive at the application servers simultaneously, weird things can happen. Sometimes, this can also happen if a user double-clicks on a button, for example.

This often leads to problems, as two object instances are modified in parallel maybe by different code and one of the requests writes the results to the database.

In case you want to make sure that only one of the requests "wins", i.e. one of the requests is fully executed and completed while the other one at least has to wait for the first request to be completed, you ha...

Rails 3 routing: Be careful with matching routes *including their format*

Today, this line made me trouble. Can you spot the mistake?

match 'sitemap.xml' => 'feeds#sitemap', :constraints => { :format => 'xml' }, :as => 'sitemap'

The mistake is to match sitemap.xml. Rails will by default strip any dot-anything, remember it as desired format and forward the rest of the request to the routing engine. Since we're making .xml part of the match, it is not available for format determination and Rails will set the format to html.

Unfortunately, the constraint won't complain in this case and Rails even ren...

Three quick Rails console tips

How to call routes, make requests and try out helpers from the Rails console.

Use a special version of Chrome for selenium (and another for your everyday work)

Sometimes you need a special version of chrome because it has some features you need for testing, like in this card. You do not need to use that Version apart from tests, because you can tweek selenium to use a special version that you set in your environment:

# features/support/chrome.rb
require "selenium/webdriver"

Capybara.register_driver :chrome320x480 do |app|
  
  if driver_path = ENV["CHROME_SELENIUM_BIN...

Run Chrome in a specific resolution or user agent with Selenium

When you want to test how an web-application reacts in a specific resolution, you can set up a specific Selenium driver for some tests:

 Before('@chrome320x480') do
     Capybara.current_driver = :chrome320x480
 end

 After('@chrome320x480') do
    Capybara.use_default_driver 
 end

You can use either chromium or chrome beta (as of 2012.05 the Version "19.0.1084.41 beta" works), or any other member of the family. It only needs to supports the "--window-size" command-line switch. [See this list](http://peter.sh...

Convert primitive Ruby structures into Javascript

Controller responses often include Javascript code that contains values from Ruby variables. E.g. you want to call a Javascript function foo(...) with the argument stored in the Ruby variable @foo. You can do this by using ERB tags (<%= ruby_expression %>) or, in Haml, interpolation syntax (#{ruby_expression}).

In any case you will take care of proper quoting and escaping of quotes, line feeds, etc. A convenient way to do this is to use Object#json, which is defined for Ruby strings, numb...

Google Analytics: Changing the tracked URL path

By default, Google Analytics tracks the current URL for every request. Sometimes you will want to track another URL instead, for example:

  • When an application URL contains a secret (e.g. an access token)
  • When you want to track multiple URLs under the same bucket
  • When you want to track interactions that don't have a corresponding URL + request (e.g. a Javascript button or a PDF download)

Luckily the Analytics code snippet allows you to freely choose what path is being tracked. Simple change this:

ga('send', 'pageview');

......

Fix warning: Cucumber-rails required outside of env.rb

After installing Bundler 1.1 you will get the following warning when running tests:

WARNING: Cucumber-rails required outside of env.rb. The rest of loading is being defered until env.rb is called.\
To avoid this warning, move 'gem cucumber-rails' under only group :test in your Gemfile

The warning is misleading because it has nothing to do with moving cucumber-rails into a :test group. Instead you need to change your Gemfile to say:

gem 'cucumber-rails', :require => false

Define a route that only responds to a specific format

You won't usually have to do this. It's OK to route all formats to a controller, and let the controller decide to which format it wants to respond.

Should you for some reason want to define a route that only responds to a given format, here is how you do it:

Rails 3

match 'sitemap.xml' => 'feeds#sitemap', :constraints => { :format => 'xml' }, :as => 'sitemap'

Rails 2

map.sitemap 'sitemap.xml', :controller => 'feeds', :action => 'sitemap', :format => 'xml'

Customize path for Capybara "show me the page" files

When you regularly make use of Cucumber's "show me the page" step (or let pages pop up as errors occur), the capybara-20120326132013.html files will clutter up your Rails root directory.

To tell Capybara where it should save those files instead, put this into features/support/env.rb:

Capybara.save_and_open_page_path = 'tmp/capybara'

Fix [RubyODBC]Cannot allocate SQLHENV when connecting to MSSQL 2005 with Ruby 1.8.7. on Ubuntu 10.10

I followed this nice guide Connecting to MSSQL with Ruby on Ubuntu - lambie.org until I ran in the following errors:

irb(main):001:0> require "dbi"; dbh = DBI.connect('dbi:ODBC:MyLegacyServer', 'my_name', 'my_password')

DBI::DatabaseError: INTERN (0) [RubyODBC]Cannot allocate SQLHENV
  from /usr/lib/ruby/1.8/dbd/odbc/driver.rb:36:in `connect'
  from /usr/lib/ruby/1.8/dbi/handles/driver.rb:33:in `connect'
  from /usr/lib/ruby...

Creating the inverse of a Rails migration

Let's say you need to revert a migration that happened a while back. You'd create a new migration that removes what was added back then in the up path, while its down path restores the old functionality.

While you could just copy&paste the down and up parts of it to the inverse part of the new migration, you may not want to do that. Especially when the up/down paths already contained some logic (that executed update statements on the created column, for example), copying does not feel right.

Someone already added the logic how to...

WebMock 1.8.0 does not play nice with Curb < 0.7.16

When updating WebMock, be prepared that your specs may send real requests into the depths of the internet unless you update Curb as well.\
WebMock will not complain about those requests not being stubbed.

One of the commits that made it into 1.8.0 actually breaks Curb versions below 0.7.16 while fixing it for that version (and above, hopefully).\
WebMock's hooks for Curl::Easy are sti...

Gatekeeping: Guide for developer

If your project manager wants to do gatekeeping on a project, as a developer you need to follow the following guidelines (e.g. by using something like this issue checklist template).

In order to reduce the number of rejects we get from clients, we want to review all code written before it goes to the staging server.


Note: This process is tailored to our specific needs and tools at makandra. While it will certainly not apply to all (especially larger tea...

Gatekeeping: Guide for gatekeeper

If you're responsible for gatekeeping in a projects, here is a guide, what to do.
In order to reduce the number of rejects we get from clients, we want to review all code written before it goes to the staging server.

Note: This process is tailored to our specific needs and tools at makandra. While it will certainly not apply to all (especially larger teams), we think it is a helpful starting point.


First, read the [Gatekeeping for developers](https://makandracards.com/makandra/6579-gatekeeping-guide-for...

RestClient sends XML Accept header by default

REST Client is a nice, simple HTTP client library for Ruby.

When you do a simple GET request like that:

RestClient.get 'http://example.com/'

it will result in this request beeing sent to www.example.com:

GET / HTTP/1.1
Accept: */*; q=0.5, application/xml
Accept-Encoding: gzip, deflate
Host: www.example.com

The application/xml accept header might lead to unexpected results on your server. You can force REST Client to ask the server for default text/html that way:

RestC...

Auto-generate Cucumber navigation paths

Don't you just hate to write Cucumber path helpers to be able to say this?

When I go to the user form for "foo@bar.de"               # goes to edit_user_path(User.find_by_anything!('foo@bar.de'))
When I go to the form for the user "foo@bar.de"           # goes to edit_user_path(User.find_by_anything!('foo@bar.de'))
When I go to the form for the user above"                 # goes to edit_user_path(User.last)
When I go to the project page for "World Domination"      # goes to project_path(Project.find_by_anything!('World Domination')
...

Use the "retry" keyword to process a piece of Ruby code again.

Imagine you have a piece of code that tries to send a request to a remote server. Now the server is temporarily not available and raises an exception. In order to re-send the request you could use the following snippet:

def remote_request
  begin
    response = RestClient.get my_request_url
  rescue RestClient::ResourceNotFound => error
    @retries ||= 0
    if @retries < @max_retries
      @retries += 1
      retry
    else
      raise error
    end
  end
  response
end

This sni...

Sunspot for Solr fails with '400 Bad Request' in 'adapt_response'

If Sunspot does not work and fails with a backtrace similar to this:

/project/shared/bundle/ruby/1.8/gems/rsolr-1.0.6/lib/rsolr/client.rb:227:in `adapt_response'
/project/shared/bundle/ruby/1.8/gems/rsolr-1.0.6/lib/rsolr/client.rb:164:in `execute'
/project/shared/bundle/ruby/1.8/gems/rsolr-1.0.6/lib/rsolr/client.rb:158:in `send_and_receive'
(eval):2:in `post'

then the schema.xml that is shipped with Sunspot is not loaded into Solr correctly.

Often the latter can be found in /etc/solr/conf/schema.xml. So copy Sunspo...