With Rails, we can build and launch a prototype application in an extremely short time. On average, we can have something simple in front of the client in less than a couple of days, which is much faster than our previous projects where we used ASP or PHP. And that project isn't usually a throwaway project; we can tweak it and move forward, from prototype to production.
In my experience, this is the single most important feature of the Ruby language---capturing the domain in a language the entire team can speak. If you believe clear communications is an essential quality of highly effective teams, this feature is something that you should strive to exploit in your own Ruby projects.Do you want to know what do I feel after reading this post?
FIELDS = [ 'first', 'last', 'band' ]
DATA = [['Kurt', 'Cobain', 'Nirvana'],
['Jimi', 'Page', 'Led Zeppelin'],
['Noel', 'Gallagher', 'Oasis'],
['Thom', 'Yorke', 'Radiohead']]
def combine_fields_and_data(fields, data)
new_data = []
data.each do |row|
row_hash = {}
row.each_with_index do |column, i|
row_hash[fields[i].to_sym] = column
end
new_data.push(row_hash)
end
return new_data
end
def combine_fields_and_data(fields, data)
data.map { |row| Hash[*fields.zip(row).flatten] }
end
module M; end
class A; end
class B < A
include M
end
b = B.new
b.kind_of? A # => true
b.kind_of? B # => true
b.kind_of? M # => true
b.class == A # => true
b.class == B # => false
b.class == M # => false
A === b # => true
B === b # => true
M === b # => true
daemon_controller is not a replacement for Monit or God, or for tools like launchd, daemons tools, inittab, etc. Rather, it is a solution to the following problem:
Hongli: hey Ninh, do a ‘git pull’, I just implemented awesome searching features in our application!
Ninh: cool. *pulls from repository*
Ninh: hey Hongli, it doesn’t work.
Hongli: what do you mean, it doesn’t work?
Ninh: it says “connection refused”, or something
Hongli: oh I forgot to mention it, you have to run the Sphinx search daemon before it works. type “rake sphinx:daemon:start” to do that
Ninh: great. but now I get a different error. something about BackgrounDRb.
Hongli: oops, I forgot to mention this too. you need to start the BackgrounDRb server with “rake backgroundrb:start_server”
Ninh: okay, so every time I want to use this app, I have to type “rake sphinx:daemon:start”, “rake backgroundrb:start_server” and “./script/server”?
Hongli: yep
Imagine the above conversation becoming just:
Hongli: hey Ninh, do a ‘git pull’, I just implemented awesome searching features in our application!
Ninh: cool. *pulls from repository*
Ninh: awesome, it works!
model_instant.new_record? # => true: just created
model_instant.new_record? # => false: created sometime ago
class Listing < ActiveRecord::Base
require_dependency "listing/property_related"
require_dependency "listing/price_related"
require_dependency "listing/contact_related"
require_dependency "listing/address_related"
require_dependency "full_text_search/listing_config"
....
end
# full_text_search/listing_config.rb
class Listing < ActiveRecord::Base
define_index do # ThinkingSphinx plugin
...
end
end
def foobar(a, b='b', c)
...
end
foobar(1, 2, 3)
# a => 1
# b => 2
# c => 3
foobar(1, 2)
# a => 1
# b => 'b'
# c => 2
define bar(a, b='b', c='c', d)
bar(1, 2, 3)
# a => 1
# b => 2
# c => 'c'
# d => 3
a = "a string"
a === "a string" # => true
a === String # => false
String === "xyz" # => true
"xyz".kind_of? String # => true
(1..5) === 3 # => true
(1..5).include? 3 # => true
/\d/ === "123" # => true
# === is used in "case" statement
b = a
a.equal? b # Returns true if the object_id’s are equal.
1 == 1.0 # => true (do type conversion)
1.==(1.0) # underlying of ==
1.eql? 1.0 # => false (don't do type conversion)
module ThinkingSphinx
class Search
class << self
alias_method :original_set_sort_options!, :set_sort_options!
def set_sort_options!(client, options)
expr = options[:sort_expr]
if expr.nil?
original_set_sort_options!(client, options)
else
client.sort_mode = :expr
client.sort_by = expr
end
end
end # class << self
end # Search
end # ThinkingSphinx