Because I don't like :)
And here is my GitHub account: https://github.com/maltize
Thursday, December 1, 2011
Friday, September 17, 2010
Ruby magic variables
Playing in irb console a little bit and I found interesting behaviour:
With this knownledge we can simlify our if / while statements.
So, as an example, we can change this:
Happy refactoring :)
irb(main):001:0> defined? x => nil irb(main):002:0> x NameError: undefined local variable or method `x' for main:Object from (irb):2 irb(main):003:0> x = 1 if false => nil irb(main):004:0> defined? x => "local-variable" irb(main):005:0> x => nilLooks like ruby allocates memory for all variables, even when the block was not executed.
With this knownledge we can simlify our if / while statements.
So, as an example, we can change this:
irb(main):012:0> if false == true irb(main):013:1> z = "not possible" irb(main):014:1> else irb(main):015:1* z = nil irb(main):016:1> end => nil irb(main):017:0> print "Output: #{z}"into this:
irb(main):019:0> if false == true irb(main):020:1> z = "not possible" irb(main):021:1> end => nil irb(main):022:0> print "Output: #{z}" Output: => nilAs you see z variable was allocated (and set to default nil) and we don't need to initialize it "one more time".
Happy refactoring :)
Thursday, September 16, 2010
Ruby/Mac/Growl: SVN new revision notifier
I would like to show you really nice and helpful notification script.
I use it to notify me of new SVN revision, but it can be easily modified and use in some different way.
Here come the script:
#!/usr/bin/env ruby while true do tmp = `svn st -u | grep '*' | cut -c 21-` tmp2 = tmp.split("\n") tmp3 = `pwd` tmp3 = tmp3.split('/').last tmp3.gsub!("\n", "") if tmp2.size > 0 message = "'#{tmp.gsub("\n", " ")}' #{tmp2.size.to_s} new files in #{tmp3}" system "growlnotify -n check_svn -m #{message} --image ./worms.png" puts message end puts Time.now.strftime('%Y-%m-%d %H:%M:%S') sleep(60) end
So, how it works?
Every 60 seconds we run svn up -u command and if there's something new in repository, we print a list of new files using growlnotify (from Growl package - http://growl.info).
That's all :)
The console output:
... and worm icon:
Sunday, August 22, 2010
RoR: Hide real id in url and html code
There are many ways to hide real ids. I'll show you one of them.
As probably most of us know we can overload to_param method for class, to show pretty well formatted slug in url, ex. 1-my_first_article
With at least this knowledge we can try to build some sort of "FunkyId" solution :)
First, create an initializer file and named it for example funky_id.rb (we can move everything from here to a plugin later) and add these lines:
to_param takes our object id and pack it somehow (described later)
But this will work only one way - all ids will be packed before showing them in url and html code.
We need also reversed process to translate OurCrazyID into ID, so our controller can use it propertly.
Now, what are these magic pak/unpak functions?
This is just our packing/unpacking implementation.
For example:
When we "unpak" some string id, we'll get integer one.
Of course, we can implement this in many diffent ways, to use only integer id for input/output and so on.
IMPORTANT
We must remember to use object instead of id in paths/params:
contact_path(@contact) instead of contact_path(@contact.id),
users_path(:role_id => @role) instead of users_path(:role_id => @role.id)
I we really, really want to use .id, additionally we need to hack a little bit ActionView::Helpers::UrlHelper::url_for function.
That's all and as I've said in the beginning,
there are many ways to do this.
Sorry for my English :)
As probably most of us know we can overload to_param method for class, to show pretty well formatted slug in url, ex. 1-my_first_article
With at least this knowledge we can try to build some sort of "FunkyId" solution :)
First, create an initializer file and named it for example funky_id.rb (we can move everything from here to a plugin later) and add these lines:
module ActiveRecord class Base def to_param id.pak end end endThis will overwrite to_param in all classes, which will inherit from ActiveRecord::Base.
to_param takes our object id and pack it somehow (described later)
But this will work only one way - all ids will be packed before showing them in url and html code.
We need also reversed process to translate OurCrazyID into ID, so our controller can use it propertly.
module ActionController class Base before_filter :unpak_id def unpak_id hash = params hash.keys.each do |key| if ( key =~ /_id$/ || key == 'id' ) id = hash[key] params[key] = id.unpak.to_s if id && id.class == String && id =~ /.+\-FID$/ end end end end endThis part will run before each controller action, trying to unpack all ids found in params.
Now, what are these magic pak/unpak functions?
This is just our packing/unpacking implementation.
For example:
class Fixnum def pak tmp = self.to_s tmp = tmp[-1..-1] + tmp.reverse tmp = Base64.encode64(tmp) tmp = tmp.strip + "-FID" tmp end end class String def unpak tmp = self[0..-5] tmp = Base64.decode64(tmp) tmp = tmp[1..-1].reverse tmp.to_i end endSo, when we "pak" some integer id, as a result we'll get string id.
When we "unpak" some string id, we'll get integer one.
Of course, we can implement this in many diffent ways, to use only integer id for input/output and so on.
IMPORTANT
We must remember to use object instead of id in paths/params:
contact_path(@contact) instead of contact_path(@contact.id),
users_path(:role_id => @role) instead of users_path(:role_id => @role.id)
I we really, really want to use .id, additionally we need to hack a little bit ActionView::Helpers::UrlHelper::url_for function.
# Not a good idea to hack this, but if you want it, you got it :) module ActionView module Helpers #:nodoc: module UrlHelper include JavaScriptHelper def url_for(options = {}) options ||= {} url = case options when String escape = true options when Hash options = { :only_path => options[:host].nil? }.update(options.symbolize_keys) options = reparse_id(options) escape = options.key?(:escape) ? options.delete(:escape) : true @controller.send(:url_for, options) when :back escape = false @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()' else escape = false polymorphic_path(options) end escape ? escape_once(url) : url end private def reparse_id hash hash.keys.each do |key| if ( key.to_s =~ /_id$/ || key == :id ) id = hash[key] if id && id.class != String hash[key] = id.pak if id.class == Fixnum hash[key] = id.id.pak if id.is_a?(ActiveRecord::Base) end end end hash end end end end
That's all and as I've said in the beginning,
there are many ways to do this.
Sorry for my English :)
Monday, April 26, 2010
Ruby: Hash to Class
How to convert hash to class, to easily use it on views (i.e. in widgets, etc.)?
Here's my solution:
class MacHash attr_accessor :hash def initialize hash self.hash = hash.symbolize_keys end def method_missing(method, *args) new_hash = hash[method] new_hash.is_a?(Hash) ? MacHash.new(new_hash) : new_hash end endAnd now we can test it:
hc = HashClass.new({:a => {:b => 10}, :c => [1, 2, 3]}) hc.a.b => 10 hc.c => [1, 2, 3]
Tuesday, December 22, 2009
Lotto (Duży Lotek) generator in Ruby
numbers = [] while(numbers.size != 6) do x = (rand(49) + 1) numbers << x unless numbers.include?(x) end numbers.sort!
Simple password generator in Ruby
The code is so simple that it needs no description:
(100000000000 + rand * 1000000000000).to_i.to_s(36)
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