DZone Snippets: Ruby on Rails code

WillPaginate RemoteLinkRenderer

chielwester (Chiel Wester) — Tue, 08 Jul 2008 10:21:45 GMT

// overrides the normal willpaginate link renderer for use with Ajax Requests and the tiny_mce_plus plugin



class RemoteLinkRenderer < WillPaginate::LinkRenderer

  def page_link_or_span(page, span_class = 'current', text = nil)

    text ||= page.to_s

    # RAILS_DEFAULT_LOGGER.error "DEBUG: page: #{page.inspect}"

    if page and page != current_page

      @template.link_to_remote text, :url => url_for(page), :method => :get

    else

      @template.content_tag :span, text, :class => span_class

    end

  end

  

  # Returns URL params for +page_link_or_span+, taking the current GET params

  # and :params option into account.

  def url_for(page)

    RAILS_DEFAULT_LOGGER.error "DEBUG: page: #{page.inspect}"

    page_one = page == 1

    unless @url_string and !page_one

      @url_params = {}

      # page links should preserve GET parameters

      stringified_merge @url_params, @template.params if @template.request.get?

      stringified_merge @url_params, @options[:params] if @options[:params]

      RAILS_DEFAULT_LOGGER.error "DEBUG: #{param_name.to_s}"

      if complex = param_name.to_s.index(/[^\w-]/)

        page_param = (defined?(CGIMethods) ? CGIMethods : ActionController::AbstractRequest).

          parse_query_parameters("#{param_name}=#{page}")

        

        stringified_merge @url_params, page_param

      else

        @url_params[param_name] = page_one ? 1 : 2

      end

      RAILS_DEFAULT_LOGGER.error "DEBUG: #{@url_params.inspect}"

      url = @template.url_for(@url_params)

      RAILS_DEFAULT_LOGGER.error "DEBUG: url: #{url.inspect}"

      return url if page_one

      

      if complex

        @url_string = url.sub(%r!((?:\?|&)#{CGI.escape param_name}=)#{page}!, '\1@')

        return url

      else

        @url_string = url

        @url_params[param_name] = 3

        @template.url_for(@url_params).split(//).each_with_index do |char, i|

          if char == '3' and url[i, 1] == '2'

            @url_string[i] = '@'

            break

          end

        end

      end

    end

    # finally!

    @url_string.sub '@', page.to_s

  end

  

  # Recursively merge into target hash by using stringified keys from the other one

  def stringified_merge(target, other)

    target = target.stringify_keys

    other = other.stringify_keys

    other.each do |key, value|

      existing = target[key]



      if value.is_a?(Hash) and (existing.is_a?(Hash) or existing.nil?)

        stringified_merge(existing || (target[key] = {}), value)

      else

        target[key] = value

      end

    end

  end

end

ActiveRecord Class Example

curtis (Curtis Hermann) — Thu, 17 Apr 2008 14:30:30 GMT

// Trying out the system, here is just a simple ActiveRecord class



class Task < ActiveRecord::Base 

  belongs_to :user

  belongs_to :location

  belongs_to :project

end .

Add a to_conditions method to ActiveRecord::Base for converting models to finder :conditions hash.

chuyeow (Chu Yeow) — Mon, 26 Mar 2007 10:54:25 GMT

// Mixes in a to_conditions method to ActiveRecord::Base. Converts the attributes of an AR object to a
// ActiveRecord::Base#find :conditions hash. Useful for comparing AR objects, especially when looking for
// duplicates.
// E.g.
//
// if not Post.find(:all, :conditions => my_post.conditions).empty?
// puts "Duplicate found"
// end



module Bezurk #:nodoc:

  module ActiveRecord #:nodoc:

    module Extensions

      def to_conditions

        attributes.inject({}) do |hash, (name, value)|

          hash.merge(name.intern => value)

        end

      end

      alias :to_conditions_hash :to_conditions

    end

  end

end



ActiveRecord::Base.send(:include, Bezurk::ActiveRecord::Extensions)

Application version number and cool codename based on subversion number

heavysixer () — Sat, 05 Aug 2006 10:10:34 GMT

// description of your code here



#codename generated from the dictionary

REVISION_NUMBER = `svn info`.split("\n")[4][/\d+/].to_i

APP_CODENAME  = IO.readlines("/usr/share/dict/words")[REVISION_NUMBER]

Add Subversion Revsions Number to Rails Application.

heavysixer () — Thu, 20 Jul 2006 04:30:56 GMT

// description of your code here
Add this to your environment.rb file for a dead easy way to get your subversion revision into your application.



APP_VERSION  = IO.popen("svn info").readlines[4]

how to escape from AJAX URL

heavysixer () — Thu, 16 Mar 2006 08:42:06 GMT

From Dylan Stamat's post on the Ruby on Rails list

Within my "login.rjs" template that get's invoked after my login process, it returns to the same page with an error message on error, or... if the login was successful, it needs to "redirect" to another controller... which is pretty much impossible to do otherwise. so, my " login.rjs" looks like:



if @logged_in_client

  page.replace_html "message", :partial => 'shared/bad_login'

else

  page.redirect_to "whatever you want here"

end

------ End Message--------
Here is my two cents:
Technically, you can do this without a RJS template at all, because it is such a simple example. Use this in your controller



render :update do |page|

  if @logged_in_client

    page.replace_html "message", :partial => 'shared/bad_login'

  else

    page.redirect_to "whatever you want here"

  end

end

Submitting data to two different tables with two different models (or how to modify multiple models from one form)

heavysixer () — Thu, 09 Mar 2006 23:20:41 GMT

Taken from Norman Timmler's example on the ruby on rails mailing list.

Take two text fields for example:



# view

<%= form_tag :controller => :posts, :action => create %>

 <%= text_field("post", "title", "size" => 20) %>

 <%= text_field("user", "email", "size" => 20) %>

<%= end_form_tag %>



# posts_controller

class PostsController < ApplicationController

 def create

   @post = Post.create(params[:post])

   @user = User.create(params[:user])

   @post.users << @user

 end

end

In the controller the params hash has one key for every object (user,
post) in your form. As a values of this key you find a hash having a
key-value pair for every object attribute (title, email).

This way you can submit multiple objects via one form.

Create a new instance of Magick::Image out of uploaded form data

heavysixer () — Thu, 09 Mar 2006 22:41:14 GMT

Taken from Norman Timmler's example on the Ruby on Rails mailing list:



def file=(new_file)

 new_file.rewind

 image = Magick::Image::from_blob(new_file.read).first

end