dospuntocero

Validation Problems

Just found out a “possible” bug when doing validations on large array of objects. When you try the following all validations are skipped (Rails 3.2.5)

 validates :name, :last_name, :age, :bla, :blah, :blah .... :foo, :presence => true, :on => :update

But found this little piece on the internet that made it all ok

 validates :name, :last_name, :age, :bla, :blah, :blah .... :foo, :presence => { :on => :update}

Weird but it worked! =)

And now you know!

Hey kids, Remember, whenever you’re using

JSONP

on your

$.ajax

calls, you’re always using GET don’t even bother trying to force a POST or any other type of HTTP methods. And now you know!

S3 Problems

After encountering this problem

Errno::EPIPE: Broken pipe

while trying to upload a file through the console using Paperclip or Carrierwave and also trying using Fog directly, I found out that the local request being sent to S3 was being rejected.
Then while trying different options I figured that ruby was calling openssl, so why not disable this and see what happened… and lo and behold it worked!
So for everyone out there just remember to add

:use_ssl => false

in this case if you’re using Paperclip in your model like so:

has_attached_file :doc,
  :path => "attachments/:id/:style/:basename.:extension",
  :storage => :s3,
  :s3_credentials => "#{Rails.root.to_s}/config/s3.yml",
  :use_ssl => false

Model default values

When looking for the best way to make default values, I’ve found that you shouldn’t rely on the DB for these. So in order to integrate these on your Model, I usually follow the next best practive:

 class User
    after_initialize :init

    def init
      self.number  ||= 0.0
    end
  end 

This way it will initialize to 0.0 if the value is nil

Custom Validation (twitter bootstrap checkbox). Part 2

After creating the custom input on Part 1, we now needed to include a custom getter for each of these inputs. We could set up a method for each input inside our model but that wouldn’t be as cool, so we create a gem with the following behavior:

Object.instance_eval do 
   def check_for_check( *attrs )
       attrs.each do | attr |
           self.class_eval %Q{
                def #{attr}
                    #{attr}_check ? read_attribute(:#{attr}) : 0
                end
           }
       end
   end
end

This will make it so that we only have to add this to our model:

check_for_check :foo, :bar

Custom Input with Twitter Bootstrap

Using simple_form and Twitter’s bootstrap we can implement a custom input for the prepend left box used in bootstrap.

First you create an inputs folder under your app directory and then a file named left_box_input.rb with the following code:

class LeftBoxInput < SimpleForm::Inputs::Base
  def input
    "<div class='input-prepend'><span class='add-on'>#{options[:symbol]}</span>#{@builder.text_field(attribute_name, input_html_options)}</div>".html_safe
  end
end

Then in your views just call it the following way:

<%= f.input :foo, :as => :left_box, :symbol => "2 + 2 ?" %>

Then you will have in your views something like this:

Custom Validation (twitter bootstrap checkbox)

After jumping the wagon with Twitter Bootstrap for a new client app we are working on, I found myself in to some problem trying to implement this type of input:

We only have one input let’s say name and we wan’t to validate it’s presence when the check is true. The check is a virtual attribute named name_check. So using simple_form gem for this form.
We need to create the custom input element first, we do this by creating an inputs folder under the app folder. We name our file prepend_checkbox_input.rb

class PrependCheckboxInput < SimpleForm::Inputs::Base
  def input
    "<div class='input-prepend'>
      <label class='add-on active' title='#{options[:tooltip]}' rel='tooltip' >
        #{@builder.check_box(attribute_name.to_s + '_check')}
      </label>
      #{@builder.text_field(attribute_name,  input_html_options)}
      <span class='help-inline'>
        #{options[:help]}
      </span>
    </div>".html_safe
  end
end

The input will include an option for tooltip, it will automatically append ‘_check’ to the name of the input to create the check box element, the text field with all the regular HTML options and a help line under it.
This will be how we call it under our views:

  <%= f.input :name, :as => :prepend_checkbox, :tooltip => "Has name?", :help => "Please insert your name" %>

Now we include validations, for custom validators we need implement this one under our initializers:

ActiveRecord::Base.class_eval do
  def self.validates_checkbox(*attrs)
    attrs.each do |attr_name|
    validates attr_name, :presence => true, :if => "#{attr_name.to_s + '_check'} == '1'" 
    end
  end
end

We user *attrs as our input so that we can declare our validations on a single line like so:

 validates_checkbox :name, :phone, :number

Rails 3.1 custom serialize

A new feature that really makes our lives easier is the custom serialize option. Let’s say that your DB requires that when you save a serializable attribute to be in a CSV form instead of the YAML default.

If this is the case then you could use the following

  class CommaSeparatedList
    def load(text)
      return unless text
      text.split(",")
    end

    def dump(text)
      text.join(",")
    end
  end

So after creating this class you just call it as a parameter in your serialize call

  serialize :names, CommaSeparatedList.new

In this way the next time you save to your DB your data will be stored in CSV form.

Rails 3.1 asset pipeline

When you’re trying out the new asset pipeline it might will be hard to debug any CSS/JS since it will all be compressed in to one file.

When you use the link/include tag remember to add the next parameter

stylesheet_link_tag :admin, :debug => Rails.env.development?
javascript_include_tag :admin, :debug => Rails.env.development?

This way it will only server the files separately when in development mode.