Notes

Note that this doesn't prevent a NoMethodError if you attempt to call a method that doesn't exist on a valid object.

a = Article.new

a.try(:author) #=> #<Author ...>

nil.try(:doesnt_exist) #=> nil

a.try(:doesnt_exist) #=> NoMethodError: undefined method `doesnt_exist' for #<Artic...

without using at [:a, :b, :c].try(:[], 1)

A somewhat different approach to the same problem:

v.gsub(/(?=\\W)/, '\\\\') #=> Foo\\ Bar\\!

But from what you are trying to achieve I suspect you might be interested in Regexp.escape method :)

Another possible gotcha -- the returned hash keys are of type String, not Symbol:

user.attributes["login"] # => "joe"
user.attributes[:login] # => nil

You can check a date resides between two dates.

Date.today.between?(Date.yesterday, Date.tomorrow)

will return true

Date.yesterday.between?(Date.today, Date.tomorrow)

will return false

If you want to expire cached pages from scripts or console just use class-method expire_page. But don't forget about difference between instance and class method. In class-method you pass page url, not a hash of action/controller:

ActionController::Base.expire_page your_page_url

I know only one possible method:

====

ApplicationController.new.expire_fragment(:your_fragment)

To specify a version range, use array syntax like this: config.gem 'paperclip', :version => ['>= 2.3.1.1', '< 3.0']

The example will, of course, match any version 2.3.1.1 or newer up until (not including) 3.0 or later.

send_file always uses the absolute path /www/somewebsite/public/downloads/file

create generates the object and saves. new only generates the object.

e.g.

o = Object.new(:foo => 'bar')
o.save

is the same as

o = Object.create(:foo => 'bar')

What's difference between create and new?

If you're trying to place a "\" in front of your matches, you'll quickly see that it is a pain in the ass to add the quoting in the replacement string.

Here's an example: v = "Foo Bar!" # Target: Foo\ Bar\! # Resulting strings will not be quoted to decrease # the amount of backslash...

Writing regular expressions is never easy. You may use http://rubular.com to test and optimize your regular expressions.

After 2.2, you can omit the do ...end block and simply use the &block variable directly: concat(content_tag(:div, :class => "wrapped_content") do capture(&block) end, block.binding)

becomes simply:

concat(content_tag(:div, capture(&block), :class => "wrapped_content"))

If you have multiple lines of javascript_include_tag 'jsfile', :cache => true, IE does not load them all (though it seems Firefox and Safari do). And the error won't show up until you're in production (since that's only when caching kicks in.)

You should include them all on one line:

javascript...

By default, content_for :thing appends whatever you put in your block to the previous value of :thing. In some cases, you'd like to clear out :thing rather than append to it.

I just posted a way to do this on my blog: http://stevechanin.blogspot.com/2009/11/clearing-out-content-in-contentfor.html...

You can also specify the format (in case you need to redirect a request coming in one format to another format):

redirect_to :action => 'show', :format => 'html'

How do I do this without actually calling the yield?

- if yield :footer
= yield :footer
- else
= render "layouts/footer_big"

(Note: HAML Syntax) Thanks.

Are you using HAML and try to do the block-thing (do...)? Please note that the whole block has to be in a single line. More: http://groups.google.com/group/haml/browse_thread/thread/52e62ef501c504a3

If you are trying to stream output via render :text => Proc and Mongrel, be sure to note that this does NOT work. Mongrel returns a StringIO, which by nature buffers everything.

Unsure of how to actually stream output with Rails in a consistent fashion.