How to set up production mode in Rails 4 with Thin and Apache

I just completed a few days of research on the problem: how can Apache serve static assets while Thin runs Rails 4 application on the given port. Apache should create far-future expires headers on assets also. So, to do this, you need some

Apache modules:

a2enmod proxy_balancer
a2enmod proxy_http
a2enmod rewrite
a2enmod headers
a2enmod expires

My Apache virtualhost config:

<virtualhost>
    ServerName my_site.com
    ServerAlias *.my_site.com
    DocumentRoot /home/my_path/my_app/public

    RewriteEngine On

    <proxy balancer:="" thinservers="">
     BalancerMember http://127.0.0.1:5000
     </proxy>
   
    <location assets="">
        Header unset ETag
        FileETag None
        ExpiresActive On
        ExpiresDefault "access plus 1 year"
    </location>

    RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f
    RewriteRule ^/(.*)$ balancer://thinservers%{REQUEST_URI} [P,QSA,L]

    # Custom log file locations
    ErrorLog  /home/my_path/my_app/log/error.log
    CustomLog /home/my_path/my_app/log/access.log combined

</virtualhost>

After then, restart your Apache service:

service apache2 restart

That was Apache configuration thanks to this post:
http://bibwild.wordpress.com/2012/11/20/apache-conf-for-rails-asset-pipeline

Setting up Thin

There is my thin configuration file in /etc/thin directory. Set environment to production my_site_name.yml:

chdir: /home/my_path/my_app
environment: production
address: 0.0.0.0
port: 5000
timeout: 30
log: log/thin.log
pid: tmp/pids/thin.pid
max_conns: 1024
max_persistent_conns: 100
require: []
wait: 30
servers: 1
daemonize: true
onebyone: true
user: my_user_name
group: my_user_name
tag: my_site_name-publ

I made a script in application's bin/ directory, my_site_name:

#!/bin/sh
#

# Start the service
start() {
    thin start -C /etc/thin/my_site_name.yml
}

# Stop the service
stop() {
    thin stop -C /etc/thin/my_site_name.yml    
}

# Start the service
restart() {
    thin restart -C /etc/thin/my_site_name.yml
}

### main logic ###
case "$1" in
  start)
        start
        ;;
  stop)
        stop
        ;;
  restart)
        restart
        ;;
  *)
        echo "Usage: $0 {start|stop|restart}"
        exit 1
esac

exit 0

This is important for start / stop / restart your Rails 4 application easily. Set this file executable. Then just restart Thin like this, in you app's directory:

bin/my_site_name restart

Configuration for production mode

First install yui-compressor gem to minify CSS also.
After then, insert gem 'therubyracer' to production section into gemfile.
 

source 'https://rubygems.org'

gem 'rails', '4.0.0'
gem 'mysql2'
gem 'sass-rails', '~> 4.0.0'

gem 'uglifier', '>= 1.3.0'
gem 'yui-compressor','~> 0.12.0'
gem 'coffee-rails', '~> 4.0.0'
gem 'coffee-script-source', '1.5.0'
gem 'therubyracer', platforms: :ruby

gem 'jquery-rails'
gem 'turbolinks'
gem 'jquery-turbolinks'

gem 'jbuilder', '~> 1.2'

group :doc do
  # bundle exec rake doc:rails generates the API under doc/api.
  gem 'sdoc', require: false
end

gem 'execjs'
gem 'savon'
gem 'faye'
gem 'thin'

group :production do
  gem 'therubyracer'
end


And run 'sudo bundle install'

See config/environments/production file:

MySiteName::Application.configure do

  # Code is not reloaded between requests.
  config.cache_classes = true

  # Eager load code on boot. This eager loads most of Rails and
  # your application in memory, allowing both thread web servers
  # and those relying on copy on write to perform better.
  # Rake tasks automatically ignore this option for performance.
  config.eager_load = true

  # Full error reports are disabled and caching is turned on.
  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true

   # Disable Rails's static asset server (Apache or nginx will already do this).
  config.serve_static_assets = false
 
  # Compress JavaScripts and CSS.
  config.assets.js_compressor = :uglifier
  config.assets.css_compressor = :yui

  # Do not fallback to assets pipeline if a precompiled asset is missed.
  config.assets.compile = false

  # Generate digests for assets URLs.
  config.assets.digest = true

  # Version of your assets, change this if you want to expire all your assets.
  config.assets.version = '1.0'

  # Specifies the header that your server uses for sending files.
  config.action_dispatch.x_sendfile_header = nil  #"X-Sendfile" # for apache

   # Set to :debug to see everything in the log.
  config.log_level = :info

   # Precompile additional assets.
  # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
  config.assets.precompile = ['*.js', '*.js.erb', '*.css', '*.css.erb', '*.js.coffee.erb']
  config.assets.precompile << %w(*.png *.jpg *.jpeg *.gif *.ico)
  config.assets.precompile += [ "images/icons/*" ]

  # Ignore bad email addresses and do not raise email delivery errors.
  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
   config.action_mailer.raise_delivery_errors = false

  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation can not be found).
  config.i18n.fallbacks = true

  # Send deprecation notices to registered listeners.
  config.active_support.deprecation = :notify

  # Disable automatic flushing of the log to improve performance.
   config.autoflush_log = false

  # Use default logging formatter so that PID and timestamp are not suppressed.
  config.log_formatter = ::Logger::Formatter.new
end

Don't forget to set config.action_dispatch.x_sendfile_header to nil and pay attention to precompile section. Add image subfolders and image extensions also.

 Now you have to compile assets to public/assets directory, but first empty cache and assets files:

rm -rf tmp/*
rm -rf public/assets/*
RAILS_ENV=production bundle exec rake assets:precompile

Don't forget to restart your Rails 4 application, but probably needs to kill thin process because assets files has been changed.

See this post also, it helped me a lot:
http://blog.55minutes.com/2012/02/untangling-the-rails-asset-pipeline-part-1-caches-and-compass/



And the result is a simple live mathematical practice site.

That's all, good luck!

Rails 3 ajax Autocomplete with jQuery and jQuery UI theme

So we want a form element with autocomplete. First thing to do is installing jquery-rails and jquery-ui-themes gems and require in Gemfile.

Then require one of the jQuery UI theme into app/assets/stylesheets/application.css

 *= require_self
 *= require_tree .
 *= require_style
 *= require jquery-ui/ui-lightness
*/

 app/assets/javascripts/application.js

//= require jquery
//= require jquery_ujs
//= require jquery-ui
//= require_tree .

Our controller responds json object in apps/controllers/accounts_controller.rb

    def search_account
        @accounts=Account.where("LOWER(name) LIKE ?", "%#{params[:name].downcase}%").limit(params[:maxRows]).order(:name)
        
        respond_to do |format|
            format.json {render :json => @accounts}
        end
    end

I've created a helper for input element app/helpers/application_helper.rb
(Take care of heredoc strings.)

    def autocomplete_input(attributes={})
        #*need* object: this form's object : "person"
        #*need* instance: searcheable object : 'account' 
        # instance_key: primary key of this instance : 'account_id'
        # value: original or default value for instance : 'Yahoo Corp.'
        # value_key: original or default value for instance_key: 252
        #*need* ajax_url: remote url for ajax call without format: url_for(:controller=> :accounts, :action=> :search, :id=>'all')
        # ajax_query_additional_params (Array): ["maxRows: 7", "anything :20"]
        #*need* ajax_query_searchable_param Object's string (String): "name" (@person.account.name)
        #*need* ajax_query_searchable_param_key Object's foreign key (String): "id" (@person.account.id)
        # min_length minimal chars to start searching: 2    
        
        if attributes.nil? then return false end
        if attributes.empty? then return false end
        object=attributes[:object]
        instance=attributes[:instance]
        if object.nil? or instance.nil? then return false end    
        object=object.to_s.downcase
        instance=instance.to_s.downcase
        instance_key=attributes[:instance_key] || instance + "_id"
        value=attributes[:value] || ""
        value_key=attributes[:value_key] || ""
        value_key_html=""
        unless value_key.to_s.empty? then
            value_key_html=" value=\""+value_key.to_s+"\"" 
        end
        ajax_url=attributes[:ajax_url]
        ajax_query_additional_params=attributes[:ajax_query_additional_params] || ""
        ajax_query_searchable_param=attributes[:ajax_query_searchable_param] || "name"
        ajax_query_searchable_param_key=attributes[:ajax_query_searchable_param_key] || "id"
        min_length=attributes[:min_length] || 2
        
        ajax_query_additional_params_formatted=""
        unless ajax_query_additional_params.nil? then
            case ajax_query_additional_params
                when Array then
                    i=0
                    ajax_query_additional_params.each do |aqap|
                        if i==0 then
                            ajax_query_additional_params_formatted=ajax_query_additional_params_formatted + aqap.to_s
                        else
                            ajax_query_additional_params_formatted=ajax_query_additional_params_formatted + ",\n" + aqap.to_s
                        end
                        i=i.next
                    end
                when String then
                    ajax_query_additional_params_formatted=ajax_query_additional_params
                when Hash then
                    i=0
                    ajax_query_additional_params.each do |aqap_key,aqap_value|
                        if i==0 then
                            ajax_query_additional_params_formatted=ajax_query_additional_params_formatted + aqap_key.to_s + ": " + aqap_value.to_s
                        else
                            ajax_query_additional_params_formatted=ajax_query_additional_params_formatted + ",\n" + aqap_key.to_s + ": " + aqap_value.to_s
                        end
                        i=i.next
                    end
            end
        end
        jquery_request_data_params="data: {\n"
        unless ajax_query_additional_params_formatted.empty? then
            jquery_request_data_params=jquery_request_data_params + ajax_query_additional_params_formatted + ",\n"
        end
        jquery_request_data_params=jquery_request_data_params + "#{ajax_query_searchable_param}: request.term\n},"
        search_field_id="search_#{object}_#{instance}"
        value_div_id="#{object}_#{instance}_log"
        hidden_field_id="#{object}_#{instance_key}"
        hidden_field_name="#{object}[#{instance_key}]"
        function_log_name="log_#{object}_#{instance}"
        
        html_text = <<HTML1
<table><tbody><tr>
    <td><input id="#{search_field_id}" class="ui-autocomplete-input"/></td>
    <td><div id="#{value_div_id}" class="ui-widget-content">#{value}</div></td>
</tr></tbody></table>
<input type="hidden" id="#{hidden_field_id}" name="#{hidden_field_name}" #{value_key_html} >

HTML1
        
         js_text = <<JS1
        
$(function() {

    function #{function_log_name}( label, id ) {
        $( "##{value_div_id}" ).html(label);
        $( "##{hidden_field_id}").val(id);
    }

    $( "##{search_field_id}" ).autocomplete({
        source: function( request, response ) {
            $.ajax({
                url: "#{ajax_url}.json",
                dataType: "json",
                #{jquery_request_data_params}
                success: function( data ) {
                    response( $.map( data, function( item ) {
                        return {
                            label: item.#{ajax_query_searchable_param},
                            value: item.#{ajax_query_searchable_param},
                            id: item.#{ajax_query_searchable_param_key}
                        }
                    }));
                }
            });
        },
        minLength: #{min_length},
        select: function( event, ui ) {
            if (ui.item) {
                #{function_log_name}( ui.item.value, ui.item.id );
            } else {
                #{function_log_name}( this.value, this.value );
            }
        },
        open: function() {
            $( this ).removeClass( "ui-corner-all" ).addClass( "ui-corner-top" );
        },
        close: function() {
            $( this ).removeClass( "ui-corner-top" ).addClass( "ui-corner-all" );
        }
    });
});
        
JS1
    concat(raw(javascript_tag(js_text)))
    concat(raw(html_text))
    end

Finally insert autocomplete element in _form.htm.erb

<div class="ui-widget">
<label for="search_account">Account:</label><br />
<% autocomplete_input(:object    => "person",
            :instance            => "account",
            :instance_key        => "account_id",
            :value               => (@person.account.name unless @person.account.nil?),
            :value_key           => @person.account_id,
            :ajax_url            => url_for(:controller => 'accounts',
                                            :action     => 'search_account',
                                            :id         => 'all'),
            :ajax_query_additional_params    => {:maxRows => 7},
            :ajax_query_searchable_param     => "name",
            :ajax_query_searchable_param_key => "id",
            :min_length          => 2
)%>
</div>
</div>

Works with Rails 3.2 and jQuery JavaScript Library v1.7.1. Good luck! Questions?

How to sort mysql table by ip address string column

There are lots of result for ordering mysql table by IP address string column on the net. These are almost hellish tricky. So I use this:

ips=Ip.where(:reserved => false).order("INET_ATON(address) ASC")

You can save numeric value of ip address also with INET_ATON, then you can get the string value by "INET_NTOA()" mysql function.

Here is the link about mysql miscellaneous functions:
http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html

Good luck!

Scriptaculous Slider in Rails3 form

So there is an excellent slider. http://madrobby.github.com/scriptaculous/slider/ It is perfect to set up a select form element where values are predefined numbers or integers. First you have to download http://script.aculo.us/downloads the slider.js file and move it to the /public/javascripts directory. Then insert this row in your layout, /app/views/layouts/application.html.erb after the defaults.

<%= javascript_include_tag "slider.js" %>

Then we define CSS style for the slider as the same as at the script.aculo.us homepage. (/app/public/stylesheets/style.css)

div.slider {
 width:256px;
 margin:10px 0;
 background-color:#ccc;
 height:10px;
 position: relative;
}

div.slider div.handle {
 width:10px;
 height:15px;
 background-color:#f00;
 cursor:move;
 position: absolute;
}

Then we create a helper for it. (/app/helpers/application_helper.rb)

def slider(attributes={})
  unless attributes.nil? then
  values=attributes[:values]
  default_value=attributes[:default_value].to_s
  object=attributes[:object].to_s
  instance=attributes[:instance].to_s
  unit=attributes[:unit] || ""
  text_div_id=object + "_" + instance + "_slider_text_div"
  slider_id=object + "_" + instance + "_slider"
        
  concat(raw(
    "<div id=\"#{slider_id}\" class=\"slider\">
       <div class=\"handle\"></div>
     </div>"
  ))

  concat(raw(hidden_field(object, instance, :value => default_value.to_i)))
  concat(raw("<div id=\"#{text_div_id}\">" + default_value + " " + unit + "</div>"))
        
  js_text = <<JS3
  (function() {
    var zoom_slider = $('#{slider_id}');
    var text_div = $('#{text_div_id}');
    var hidden_item = $('#{object + "_" + instance}');
    var values=#{values.inspect};
    
    var values_length = values.length;
    var min=40;
    var max=200;

    var unit = Math.ceil((max - min) / values_length);
    var range = $R(min, max - unit);

    var pix_values = new Array();
    for(i=1;i<=values_length;i++){
      pix_values[i-1]=min + (unit * (i - 1));
    }
        
    var default_value=pix_values[#{values.index(default_value.to_i)}];

    new Control.Slider(zoom_slider.down('.handle'), zoom_slider, {
      range: range,
      sliderValue: default_value,
            increment: unit,
            values: pix_values,
      onSlide: function(value) {
                text_div.innerHTML=values[pix_values.indexOf(value)] + " #{unit}";
                hidden_item.value=values[pix_values.indexOf(value)];
      },
      onChange: function(value) { 
                text_div.innerHTML=values[pix_values.indexOf(value)] + " #{unit}";
                hidden_item.value=values[pix_values.indexOf(value)];
      }
    });
  })();
        
JS3
      concat(raw(javascript_tag(js_text)))
  end
end

Then just define your form element in your view / form:

<table><tbody><tr><td>
<% slider :object        => "config",
          :instance      => "mem_size",
          :unit          => "MB",
          :values        => [512, 1024, 1536, 2048, 2560, 3072, 4096].sort,
          :default_value => 1024 %>
</td></tr></tbody></table>

That"s all! Questions?

Rails3 UTF-8 support for strings

There is a general problem in rails 3 with utf8 string support. For example upcase, downcase, titleize or capitalize. Basically these methods produce ASCII strings because of lots of memory usage of unicode strings. mb_chars string method do the trick. Create a new rb file in /lib:

[String].each do |klass|
  klass.class_eval <<-RUBY, __FILE__, __LINE__
 
 def utf8_downcase
  mb_chars.downcase.to_s
 end
 
 def utf8_upcase
  mb_chars.upcase.to_s
 end
 
 def utf8_capitalize
  mb_chars.capitalize.to_s
 end

 def utf8_titleize
  mb_chars.titleize.to_s
 end

RUBY
end

Works with Rails 3.0.7 and Ruby 1.8 surely. Don't forget to put in config/application.rb this row after require 'rails/all':

Dir.glob("./lib/*.{rb}").each { |file| require file }

Now you can call:

irb(main):005:0> "é ÉÚŐÚ ééé ŐŐÚSDFSF".utf8_downcase
=> "é éúőú ééé őőúsdfsf"

That's all. Questions?

How to submit an ajax form in javascript with Rails3 and Prototype

So there is a Rails 3 problem, when you want to submit a form in javascript (without a submit button), it is working on normal way, not ajax. But we can do creating a hidden submit button and then initializing a click event on it what is exactly doing ajax submission. The submit(); is not working anymore because it doesn't call the rails.js functions. It just works when you simple want to create a not ajax post without any confirmation. Let's see an ajax example in view's index.html.erb file:

<%= form_tag "some_url",
 :remote  => true,
 :method  => :post,
 :name  => "some_procedure",
 :id   => "some_procedure" %>
<%= submit_tag 'procedure_submit_button', :id =>"procedure_submit_button" , :style => "display: none" %>

You can add here your html code for form and create some element what is doing the submission inside a table, for a td:

<td onclick="javascript: procedure_init();" style="cursor: pointer;">

put here an image for example

</td>

</form>

<%= javascript_tag <<-RUBY
function procedure_init()
{
 var submit_button="procedure_submit_button";
 var form_name="some_procedure";
 // here you can build the form, or modify form parameters
 $(submit_button).click();
}
RUBY
%>

If you have problems with sessions or current_user quits within ajax rendering, put this code to public/javascripts/application.js. /thanks to this answer/

document.observe("dom:loaded", function() {
 Ajax.Responders.register({
  onCreate: function(request) {
   var csrf_meta_tag = $$('meta[name=csrf-token]')[0];
   if (csrf_meta_tag) {
    var header = 'X-CSRF-Token',
      token = csrf_meta_tag.readAttribute('content');

    if (!request.options.requestHeaders) {
     request.options.requestHeaders = {};
    }
    request.options.requestHeaders[header] = token;
   }
  }
 });
});

That's all. Questions?

Each loop for a class or model instance variables

Sometimes we need to check all of instance variables in a class or model one by one. In this exaple we will check if a varaible is an Array or not:

your_model.instance_variables.each do |i|
 if your_model.instance_variable_get(i).instance_of?(Array) then
  #your code to do anything with your_model.instance_variable_get(i) what is a value
 end
end

If you have an active record model, you can do:

@account = Account.first

Account.column_names.each do |i|
  @account.instance_eval(i)
 # row returns @account.name for example inside the loop, next @account.address and so on
end

That's all!

How to get requested controller name, action name and id in Rails3 view

To get requested controller name, action name and id in view we will call a simple helper function. For example we have the '/users/show/23' request, by routing rule: 'match ':controller(/:action(/:id(.:format)))''

#to get controller name:
<%= controller.controller_name %>
#=> 'users'

#to get action name, it is the method:
<%= controller.action_name %>
#=> 'show'


#to get id information:
<%= ActionController::Routing::Routes.recognize_path(request.url)[:id] %>
#=> '23'

That's all!

I18n yml files in Rails3

Your locale files are located in config/locales directory by default. Let's make two locale files: en.yml and for example: hu.yml. In that files we can describe our string translations what we will use in our page view with helpers. Take care of yml rules, you can use spaces only instead of tabs, and spaces determine level of string. You can use double quotes to define a string, but if you want to use quotes inside the string, use html entity: " for it. You can use html in strings fo course, but don't forget raw helper in view before. Finally, you can give variables to yml simply, between %{var} (in rails2: {{var}} ) signs and full string needs to be between double quotes. I used to create yml blocks by controllers.

Labels are very simple also. Just take under helpers: and controller_name: (helpers: and contact: in the example below). Submit definitions are the same like labels.

en:
  contact:
    prices:
      show_price: "%{price_dollar}$"
      quote: "Coordinator: & quot;Crucifixion?& quot? & lt;br /& gt; Mr. Cheeky: & quot;Er, no, freedom actually.& quot;"

  attributes:
    created_at: "Created at"
    updated_at: "Updated at"

  helpers:
    submit:
      contact:
        create: "Order"
        update: "Modify"
    label:
      contact:
        name: "Your name"
        company_name: "Company name"
        phone: "Phone number"
        email: "E-mail"
        comment: "Comment"

  date:
    formats:
      default: "%Y-%m-%d"
      short: "%b %d"
      long: "%B %d, %Y"
    day_names: [Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday]
    abbr_day_names: [Sun, Mon, Tue, Wed, Thu, Fri, Sat]
    month_names: [~, January, February, March, April, May, June, July, August, September, October, November, December]
    abbr_month_names: [~, Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec]
    order: [ :year, :month, :day ]
 
  time:
    formats:
      default: "%a, %d %b %Y %H:%M:%S %z"
      short: "%d %b %H:%M"
      long: "%B %d, %Y %H:%M"
    am: "am"
    pm: "pm"

And the reference in our view file (apps/views/contact/index.html.erb):

<%= form_for @contact, :as   => :contact,
   :url  => {:action => 'new'},
   :html => {} do |f| %>

<%=f.label :name %>

<%= f.submit %>

<%=t :show_price, :scope => [:contact, :prices], :price_dollar => 50 %>

<%=raw t(:quote, :scope => [:contact, :prices], :locale=>'en') %>
<%=l Date.today, :format => :long %>

You can define exact locale in view like :locale=>'hu'. Localize dates with l helper function. You can use I18n.locale in controller for getting current locale. You can get all locales in an array with: I18n.available_locales . Don't forget to check application.rb in config directory, where you can setting up default locale:

config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
     config.i18n.default_locale = :hu

Then make a method in app/controllers/application_controller.rb for users to change their language and create a before_filter:

class ApplicationController < ActionController::Base
protect_from_forgery
before_filter :set_locale

  def set_locale
  locale = params[:locale] || session[:locale] || I18n.default_locale.to_s
  locale = I18n.available_locales.include?(locale.to_sym) ? locale : 18n.default_locale.to_s
  session[:locale] = I18n.locale = locale
  end
end

Then create your link to set locale in your layout: link_to('English', url_for(:locale => 'en')). That's all! Questions?

Rails3 ajax tricks with javascript erb templates

This guide is about rails3 ajax and javascript tricks. (Unobtrusive javascript, if it sounds better.) first, you must decide what do you want to do and how. Sometimes there are better solutions than we should think first. To call an ajax method, you must take the code in view header (or layout): <%= javascript_include_tag :defaults %>

Using js.erb templates.

If you decided to use some ajax calls, using server-side programming, recommend to create a new ajax controller (but it's not necessary). In command line:

rails g controller ajax

Then, if we make an ajax call, we will define procession in app/controllers/ajax_controller.rb. Next, we define the javascript output in ajax_controller.rb with respond_to, and define our methods (now: empty_cart):

class AjaxController < ApplicationController
respond_to :js

  def empty_cart
    Cart.where(:session_id => request.session_options[:id]).destroy_all
  end

end

Then we can create empty_cart.js.erb in app/views/ajax/ directory. In this file we define javascript what sends to page. This is javascrip template, but we can use ruby expressions in it. Of course, we can use prototype methods and script.aculo.us effects. The partial cart.html has been defined in layouts and if cart is empty, it will show one row: "the cart is empty". The element will be replaced by partial:

$("cart_div").update("<%= escape_javascript(render("layouts/partials/cart.html.erb")) %>");
new Effect.Highlight("cart_div", {duration: 1.5, startcolor: "#909090"});

After then, we can create this ajax link in our view, now: layouts/partials/cart.html.erb. We make it with a button defined in css.

<% if Cart.where(:session_id => request.session_options[:id]).empty? %>

Cart is empty.

<% else %>

..put here your cart html code..

<%=raw form_tag url_for(:action => "empty_cart",
  :controller => :ajax ),
{ :method => :post,
  :remote => true,
  'data-confirm'  => "Are you sure?" } %>
<%=raw submit_tag "Empty Cart",
  :id  => "empty_cart_submit",
  :class  => "empty_cart_button"
   %>
</form>

<% end %>

Don't forget to set link html options :remote => true, to call an ajax method.

The right syntax of the link_to function with i18n is:

<%= link_to [t :empty_cart, :scope  => [:application]],
  url_for(:controller => 'ajax',
          :action  => "empty_cart"),
  {:method => :post,
   :remote  => true,
   :confirm => "Are you sure?"}
%>

Using effects

You can use any effects in javascript erb template like in pure javascript. For example a toggle effect:

new Effect.toggle("some_div_<%= id %>", "slide", {duration: 0.2});

Don't forget to put ruby expressions between <%= %> tags like in html view.

Forgetting observe_form and observe_field

In rails 2 there were these functions observe_form and observe_field, now, in rails3 are missing. You can use Prototype Legacy Helper plugin, or, I recommend to create your own javascript code, what is faster than calling an ajax method. Put your javascript code into your form view (app/views/controller_name/form.html.erb):

<%=raw javascript_tag "
document.observe("dom:loaded", function()
{
new Form.Observer("<%= @jsvalidator.form.id %>", 0.3, function(form, value)
 {
// now we got form values in one single url-formed linein value javascript variable
// so we create an array of key and value pairs in textArray
  var textArray=unescape(value).split("&");
  var i=0;
  for(i=0; i<(textArray.length); i++)
  {
// then, you can see all elements within a for loop  
// now textArray[i] is one line like: "form_element_name=form_element_value"
 
   value_line_with_equal_sign=textArray[i];
   value_name="";
   value_value="";
   value_name=value_line_with_equal_sign.split("=",2)[0];
   value_value=value_line_with_equal_sign.split("=",2)[1];
// now you can check all of form values in this loop, value_name is the form element name
// value_value is form element's value
// probably you must give form elements to Form class
 
}
 
}
}" %>

@jsvalidator object has been created in form's controller with form datas. See more information: How to generate inline javascript

If you have problems with Internet Explorer, IE see and download newer versions of rails.js and prototype.js. Details here.

If you have problems with sessions or current_user quits within ajax rendering, put this code to public/javascripts/application.js. /thanks to this answer/

document.observe("dom:loaded", function() {
 Ajax.Responders.register({
  onCreate: function(request) {
   var csrf_meta_tag = $$('meta[name=csrf-token]')[0];
   if (csrf_meta_tag) {
    var header = 'X-CSRF-Token',
      token = csrf_meta_tag.readAttribute('content');

    if (!request.options.requestHeaders) {
     request.options.requestHeaders = {};
    }
    request.options.requestHeaders[header] = token;
   }
  }
 });
});

That's all!

How to load i18N locale files in rails3 with our new gem

That is very simple. We'll create a gem with our own locale files, first, we create the locale files in our gem's lib/locales directory (en.yml and hu.yml for example). There would be our gem's .rb file in lib directory (example.rb). Don't forget to specify these files in gemspec. Now we can create a new method: translate_string in our 'lib/example.rb'.

class Example
require 'rubygems'
require 'active_support'
require 'i18n'


path=File.dirname(__FILE__)
I18n.load_path += Dir[ File.join(path, 'locales', '*.{rb,yml}') ]

def initialize
end

def translate_string(var)
  return I18n.t(var, :scope=>[:example, :vars])
end

end

Then, we can create our locale files 'lib/locales/en.yml' like this:

en:
  example:
    vars:
      title: example

And our lib/locales/hu.yml:

hu:
  example:
    vars:
      title: példa

Take care of spaces instead of tabs. After we build our gem and insert to Gemfile (what is in our Rails3 application) we can call our new class in our controller. Don't forget to restart your application before.


e=Example.new
e.translate_string("title")


This gives "example". That's all!

Create new class in Rails3 with hash parameters

This guide is about how to create new class with hash parameters, without ActiveRecord. If you don't want to use database to define a new object, this guide is for you. First, we create a new contact.rb file in "app/models" directory

class Contact
 include ActiveModel::Serialization
 attr_accessor :name, :company_name, :email, :phone, :comment

 def initialize(attributes = {})
  @name=attributes[:name]
  @company_name=attributes[:company_name]
  @email=attributes[:email]
  @phone=attributes[:phone]
  @comment=attributes[:comment]
 end
 
# persisted is important not to get "undefined method `to_key' for" error
 def persisted?
  false
 end 
 
end

And then you can use this model to create a new form, like ActiveRecord in controllers:

@contact=Contact.new

or

@contact=Contact.new(params[:contact])

Now we can use this object to send email to sales or save it to another object's text column with json. For example if there is a json_contact text column in User active_record object, users.rb:

Class User < ActiveRecord::Base
before_save :before_save_function

def before_save_function
  unless self.json_contact.is_a?(String) then
    # we need this condition because if we updating, must know if it is a String (json modelled class) or a Contact model class
    self.json_contact=self.json_contact.to_json
  end
  true
 end

 def contact
  unless self.json_contact.nil? then
   contact_hash = ActiveSupport::JSON.decode(self.json_contact).symbolize_keys.clone
   return Contact.new(contact_hash)
  else
   return nil
  end
 end

end

Then you can give a Contact object to User.json_contact like:

@user=... # your turn (find, or create) @contact=Contact.new(params[:contact]) @user.json_contact=@contact @user.save

Don't forget to restart your application after modifying anything in your models. Now you can get original User.contact as an object, and you can use it like Contact model:

contact_name=@user.contact.name

That's all

How to generate inline javascript by gem for form validation etc...

This tutorial is about generating an inline javascript by gem created by us. This can be usable for form validation or another javascript application. This tutorial is for Ruby on Rails 3. I don't write full code, because it could be too deep, I just try to show to you how to give inline javascript code by  js template to a single view page.

First, we need to create our own gem file structure:

- jsvalidator

- lib

- jsvalidator.js.erb
- jsvalidator.rb

- jsvalidator.gemspec

Then we edit the jsvalidator.gemspec file which is in jsvalidator directory have been created.

Gem::Specification.new do |spec|
   spec.name = 'jsvalidator'
   spec.version ='0.0.1'
   spec.files = ["lib/jsvalidator.js.erb", "lib/jsvalidator.rb"]
   spec.summary = "Javascript form validator for rails3 with javascript."
   spec.author = 'Programmer'
   spec.email = 'programmer@yourdomain.com'
   spec.homepage = 'http://www.yourdomain.com'
   spec.has_rdoc = false
 end 

We create our class structure in jsvalidator.rb file. You can install erubis gem with "gem install erubis" command.

require 'rubygems'
require 'active_support'
require 'erubis'

class Jsvalidator
# define a form object
attr_accessor :form

def form
 return @form
end


# now we don't initialize anything, but you can set initial values in this block
def initialize
end

# we create a function to define our form, what is now an another object class defined later
def define_form(attributes={})
 f=Form.new(attributes)
 @form=f if f
end

# jsvalidator_helper is a function, we will call using Jsvalidator class
 def jsvalidator_helper
# __FILE__ is the path where the this rb file is 
  path=File.dirname(__FILE__)
  template_path=File.join(path, 'jsvalidator.js.erb')
# we can give objects to javascript template like @jsvalidator, what is self in this case,
# beacuse now we work with Jsvalidator class only
  vars={ '@jsvalidator' => self }
# so read the javascript template
  template= File.read(template_path)
# Erubis can execute inline ruby expressions with objects (formed like: <%= @jsvalidator.any %>)
  javascript=Erubis::Eruby.new(template).result(vars)
# then we create return string
  javascript=""
  return javascript
 end

#end of Jsvalidator class
end

# then we must define our Form class
class Form < Jsvalidator
# You can create any object in it, now we use form.id only
attr_accessor :id
def initialize(attributes={})
  @id=attributes[:id]
end
end

In this file we should create our model, or data structure, we will use at jsvalidator.html.erb in another function of course. Then, we edit the jsvalidator.js.erb file. In this file we define our javascript code, but remember, this is a template, so you can use ruby expressions like: <%= @jsvalidator.anything %>, but first you must define objects in Form class. Now we use @form.id only.

document.observe("dom:loaded", function()
{
new Form.Observer("<%= @jsvalidator.form.id %>", 0.3, function(form, value)
 {
// now we got form values in one single url-formed linein value javascript variable
// so we create an array of key and value pairs in textArray
  var textArray=unescape(value).split("&");
  var i=0;
  for(i=0; i<(textArray.length); i++)
  {
// then, you can see all elements within a for loop  
// now textArray[i] is one line like: "form_element_name=form_element_value"

   value_line_with_equal_sign=textArray[i];
   value_name="";
   value_value="";
   value_name=value_line_with_equal_sign.split("=",2)[0];
   value_value=value_line_with_equal_sign.split("=",2)[1];
// now you can check all of form values in this loop, value_name is the form element name
// value_value is form element's value
// probably you must give form elements to Form class

}

}
} 

After then, you can build your gem file at jsvalidator directory at command line:

gem build jsvalidator.gemspec

and install:

sudo gem install jsvalidator

Then edit your Gemfile, what is located at your rails3 application's directory, and insert this line with your real path:

gem 'jsvalidator', :path = "/home/user/gems/jsvalidator", :require = "jsvalidator"

Then type command line:

bundler update

If you don't want to create a working gem because of developing, you can just simply add to your application_controller.rb file this line with your path:

require '/home/user/gems/jsvalidator/lib/jsvalidator.rb'

Now at your view file, you just simply call helper like this:

<% @jsvalidator=Jsvalidator.new %>
<% @jsvalidator.define_form( :id => "your_form_id" ) %>
<%= raw @jsvalidator.jsvalidator_helper %>

That's all.