Tag Archives: ruby

When appending to a string in Ruby use the << method instead of +=

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When appending to a string in Ruby use the << method instead of +=

If you come from another language, you might be tempted to use the += operator when appending to a string.

  1. my_str = “Marco ”
  2. my_str += “Polo”

It works… but there is a better way to do it : the « method.

  1. my_str = “Marco ”
  2. my_str « “Polo”

#UPDATE
I have removed my initial claim about operator precedence as it isn’t really accurate. There is a much better reason to use « instead of += when appending to a string… something I didn’t even realize (Thanks to Gregory). += will create a new String instance and will assign it to your left object. On the other hand, « will append the new string directly into your already existing left object. One could argue that += is only different than « and not better, but to me « is what you’ll want to use 99% of the time (if not 100%) when appending to a String. I have yet to see a real case where one would want to “lose” it’s existing String instance just to get a new one containing the exact same value.

You can also use the « method with arrays :

  1. [1,2,3] « 4 #gives [1,2,3,4]

Be careful however when using « with Fixnum/Bignum instances. With these objects, the « method will shift the bits of your integer to the left. If you want to do a summation (append style that is), you will have to use +=

Preserve Rails Ferret Index with a Symlink and Capistrano

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Preserve Rails Ferret Index with a Symlink and Capistrano

First, deploy your app and build your index. Once that’s done, copy your index folder to the shared folder:


cp -R /path/to/your/app/current/index /path/to/your/app/shared/

Lastly, in your deploy.rb file that you use to control your deployments, tell capistrano to create a symlink to the shared directory for your ferret index:


desc &quot;Preserve ferret index&quot; 
task :after_update_code, :roles =&gt; [:web] do
  run &lt;&lt;-EOF
    ln -s #{shared_path}/index #{latest_release}/index
  EOF
end

Simple static pages in ruby on rails.

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Simple static pages in ruby on rails.

simple pages

— April 2, 2008 at 09:38 PDT

Simple things should be simple, complex things should be possible. — Alan Kay

Here’s a tiny little tip for handling those boiler-plate pages that aren’t part of your app’s functionality but you usually need anyway. It’s good for setting up about, contact, copyright, etc. You can always throw those pages into /public as static html files, but if you want them to get styled with layouts, they need to be rendered as actions. This is a way to do that simply. It’s not rocket science, but I haven’t done a noob post in ages and I’m getting over a cold and I haven’t posted in too long so gimme a break.

Say you want to have a simple landing page and a few typical boiler-plate pages. Let’s start with the routes.

In config/routes.rb

map.root :controller => 'home'
map.home ':page', :controller => 'home', :action => 'show', :page => /about|contact/

In app/controllers/home_controller.rb

def index
  # render the landing page
end

def show
  render :action => params[:page]
end

Throw your about.html or about.html.erb and other pages into app/views/home and you’re good to go. If you’ve set up page caching, this won’t even slow your app down.

The :page => /.../ bit in the route constrains it to match only those specific urls. If you want, you can change that to a constant, like HomeController::PAGES, so it’s easier to manage.

If you want to link to those pages, you can use the route helper methods, home_path and home_url

link_to 'About', home_path('about')

You could always unroll the routes and have a separate route for each page, but I find this way a bit drier. But if you’d rather have a specific named route helper for each page, that’s an okay way to go. Either way, you get to use layouts in your pages, and have a nice simple way to get them rendered.