How to use view helpers in my ActionMailer views?

If you want to use a helper in mailers:

You can just add in your mailer

helper ApplicationHelper

or whatever helper you need

class MyMailer < ApplicationMailer
helper ApplicationHelper
end

Determine if asset exists?

Determine if asset exists?

 Rails.application.assets.find_asset("cards/header.png")
 => #<Sprockets::Asset:1d346d0 "file:///home/saritha/sites/new_app/app/assets/images/cards/header.png?type=image/png&id=d571d3707e9e08e6527f5c6049742fc7a13672b43ebbcffe625c8986d31c3759">

Rails.application.assets.find_asset 'notthere.png'
 => nil

Rails.application.assets.find_asset("cards/header.png").present?
=> true

Rails.application.assets.find_asset("cards/notthere.png").present?
=> false

Let’s play with ruby function to remove all white spaces.

1.9.3p125 :001 > a = “Miasa Pride”

 => “Miasa Pride”

1.9.3p125 :002 > a.strip

 => “Miasa Pride”

1.9.3p125 :006 > a.gsub(/\s+/, “”)

 => “MiasaPride”

1.9.3p125 :007 > b = ” Miasa Pride “

 => ” Miasa Pride “

1.9.3p125 :008 > b.gsub(/\s+/, “”)

 => “MiasaPride”

1.9.3p125 :009 > c = ” Miasa@Pride “

 => ” Miasa@Pride “

1.9.3p125 :010 > c.gsub(/\s+/, “”)

 => “Miasa@Pride”

2.2.2 :019 > a.delete("")

 => "Miasa Pride" 

2.2.2 :020 > a.delete(" ")

 => "MiasaPride" 

2.2.2 :021 > 

Cheers….!!!!!!!!

How do I pass a hash with hidden_field or hidden_field_tag:

<%= text_field 'item_quantity', item.id, :value => item.quantity %>

then parameters:

"item_quantity"=>{"56372b6ce5d9832c6f000002"=>"1", "5637442ae5d9832c6f00002b"=>"5"}